Merge pull request #23429 from Jokser/disk-s3-restart-possibility

2024-11-21 15:12:02 +00:00 · 2021-05-01 15:28:14 +03:00 · 2021-05-01 15:28:14 +03:00 · 3b7c68196b
commit 3b7c68196b
parent 9f369a0a27 0050dbb75b
27 changed files with 1135 additions and 417 deletions
--- a/src/Access/AccessType.h
+++ b/src/Access/AccessType.h
@ -133,6 +133,7 @@ enum class AccessType
    M(SYSTEM_RELOAD_MODEL, "SYSTEM RELOAD MODELS, RELOAD MODEL, RELOAD MODELS", GLOBAL, SYSTEM_RELOAD) \
    M(SYSTEM_RELOAD_EMBEDDED_DICTIONARIES, "RELOAD EMBEDDED DICTIONARIES", GLOBAL, SYSTEM_RELOAD) /* implicitly enabled by the grant SYSTEM_RELOAD_DICTIONARY ON *.* */\
    M(SYSTEM_RELOAD, "", GROUP, SYSTEM) \
+    M(SYSTEM_RESTART_DISK, "SYSTEM RESTART DISK", GLOBAL, SYSTEM) \
    M(SYSTEM_MERGES, "SYSTEM STOP MERGES, SYSTEM START MERGES, STOP_MERGES, START MERGES", TABLE, SYSTEM) \
    M(SYSTEM_TTL_MERGES, "SYSTEM STOP TTL MERGES, SYSTEM START TTL MERGES, STOP TTL MERGES, START TTL MERGES", TABLE, SYSTEM) \
    M(SYSTEM_FETCHES, "SYSTEM STOP FETCHES, SYSTEM START FETCHES, STOP FETCHES, START FETCHES", TABLE, SYSTEM) \
--- a/src/Disks/DiskCacheWrapper.cpp
+++ b/src/Disks/DiskCacheWrapper.cpp
@ -1,20 +1,22 @@
 #include "DiskCacheWrapper.h"
 #include <IO/copyData.h>
+#include <IO/ReadBufferFromFileDecorator.h>
+#include <IO/WriteBufferFromFileDecorator.h>
 #include <Common/quoteString.h>
 #include <condition_variable>

 namespace DB
 {
 /**
- * Write buffer with possibility to set and invoke callback when buffer is finalized.
+ * Write buffer with possibility to set and invoke callback after 'finalize' call.
 */
-class CompletionAwareWriteBuffer : public WriteBufferFromFileBase
+class CompletionAwareWriteBuffer : public WriteBufferFromFileDecorator
 {
 public:
-    CompletionAwareWriteBuffer(std::unique_ptr<WriteBufferFromFileBase> impl_, std::function<void()> completion_callback_, size_t buf_size_)
-        : WriteBufferFromFileBase(buf_size_, nullptr, 0), impl(std::move(impl_)), completion_callback(completion_callback_) { }
+    CompletionAwareWriteBuffer(std::unique_ptr<WriteBufferFromFileBase> impl_, std::function<void()> completion_callback_)
+        : WriteBufferFromFileDecorator(std::move(impl_)), completion_callback(completion_callback_) { }

-    ~CompletionAwareWriteBuffer() override
+    virtual ~CompletionAwareWriteBuffer() override
    {
        try
        {
@ -31,31 +33,13 @@ public:
        if (finalized)
            return;

-        next();
-        impl->finalize();
-
-        finalized = true;
+        WriteBufferFromFileDecorator::finalize();

        completion_callback();
    }

-    void sync() override { impl->sync(); }
-
-    std::string getFileName() const override { return impl->getFileName(); }
-
 private:
-    void nextImpl() override
-    {
-        impl->swap(*this);
-        impl->next();
-        impl->swap(*this);
-    }
-
-    /// Actual write buffer.
-    std::unique_ptr<WriteBufferFromFileBase> impl;
-    /// Callback is invoked when finalize is completed.
    const std::function<void()> completion_callback;
-    bool finalized = false;
 };

 enum FileDownloadStatus
@ -200,8 +184,7 @@ DiskCacheWrapper::writeFile(const String & path, size_t buf_size, WriteMode mode
            auto dst_buffer = DiskDecorator::writeFile(path, buf_size, mode);
            copyData(*src_buffer, *dst_buffer);
            dst_buffer->finalize();
-        },
-        buf_size);
+        });
 }

 void DiskCacheWrapper::clearDirectory(const String & path)
@ -316,22 +299,6 @@ void DiskCacheWrapper::createDirectories(const String & path)
    DiskDecorator::createDirectories(path);
 }

-/// TODO: Current reservation mechanism leaks IDisk abstraction details.
-/// This hack is needed to return proper disk pointer (wrapper instead of implementation) from reservation object.
-class ReservationDelegate : public IReservation
-{
-public:
-    ReservationDelegate(ReservationPtr delegate_, DiskPtr wrapper_) : delegate(std::move(delegate_)), wrapper(wrapper_) { }
-    UInt64 getSize() const override { return delegate->getSize(); }
-    DiskPtr getDisk(size_t) const override { return wrapper; }
-    Disks getDisks() const override { return {wrapper}; }
-    void update(UInt64 new_size) override { delegate->update(new_size); }
-
-private:
-    ReservationPtr delegate;
-    DiskPtr wrapper;
-};
-
 ReservationPtr DiskCacheWrapper::reserve(UInt64 bytes)
 {
    auto ptr = DiskDecorator::reserve(bytes);
--- a/src/Disks/DiskDecorator.cpp
+++ b/src/Disks/DiskDecorator.cpp
@ -196,4 +196,19 @@ void DiskDecorator::onFreeze(const String & path)
    delegate->onFreeze(path);
 }

+void DiskDecorator::shutdown()
+{
+    delegate->shutdown();
+}
+
+void DiskDecorator::startup()
+{
+    delegate->startup();
+}
+
+void DiskDecorator::applyNewSettings(const Poco::Util::AbstractConfiguration & config, ContextConstPtr context)
+{
+    delegate->applyNewSettings(config, context);
+}
+
 }
--- a/src/Disks/DiskDecorator.h
+++ b/src/Disks/DiskDecorator.h
@ -65,12 +65,33 @@ public:
    String getUniqueId(const String & path) const override { return delegate->getUniqueId(path); }
    bool checkUniqueId(const String & id) const override { return delegate->checkUniqueId(id); }
    DiskType::Type getType() const override { return delegate->getType(); }
-    Executor & getExecutor() override;
    void onFreeze(const String & path) override;
    SyncGuardPtr getDirectorySyncGuard(const String & path) const override;
+    void shutdown() override;
+    void startup() override;
+    void applyNewSettings(const Poco::Util::AbstractConfiguration & config, ContextConstPtr context) override;

 protected:
+    Executor & getExecutor() override;
+
    DiskPtr delegate;
 };

+/// TODO: Current reservation mechanism leaks IDisk abstraction details.
+/// This hack is needed to return proper disk pointer (wrapper instead of implementation) from reservation object.
+class ReservationDelegate : public IReservation
+{
+public:
+    ReservationDelegate(ReservationPtr delegate_, DiskPtr wrapper_) : delegate(std::move(delegate_)), wrapper(wrapper_) { }
+    UInt64 getSize() const override { return delegate->getSize(); }
+    DiskPtr getDisk(size_t) const override { return wrapper; }
+    Disks getDisks() const override { return {wrapper}; }
+    void update(UInt64 new_size) override { delegate->update(new_size); }
+
+private:
+    ReservationPtr delegate;
+    DiskPtr wrapper;
+};
+
+
 }
--- a/src/Disks/DiskRestartProxy.cpp
+++ b/src/Disks/DiskRestartProxy.cpp
@ -0,0 +1,311 @@
+#include "DiskRestartProxy.h"
+
+#include <IO/ReadBufferFromFileDecorator.h>
+#include <IO/WriteBufferFromFileDecorator.h>
+
+namespace DB
+{
+namespace ErrorCodes
+{
+    extern const int DEADLOCK_AVOIDED;
+}
+
+using Millis = std::chrono::milliseconds;
+using Seconds = std::chrono::seconds;
+
+/// Holds restart read lock till buffer destruction.
+class RestartAwareReadBuffer : public ReadBufferFromFileDecorator
+{
+public:
+    RestartAwareReadBuffer(const DiskRestartProxy & disk, std::unique_ptr<ReadBufferFromFileBase> impl_)
+        : ReadBufferFromFileDecorator(std::move(impl_)), lock(disk.mutex) { }
+
+private:
+    ReadLock lock;
+};
+
+/// Holds restart read lock till buffer finalize.
+class RestartAwareWriteBuffer : public WriteBufferFromFileDecorator
+{
+public:
+    RestartAwareWriteBuffer(const DiskRestartProxy & disk, std::unique_ptr<WriteBuffer> impl_)
+        : WriteBufferFromFileDecorator(std::move(impl_)), lock(disk.mutex) { }
+
+    virtual ~RestartAwareWriteBuffer() override
+    {
+        try
+        {
+            RestartAwareWriteBuffer::finalize();
+        }
+        catch (...)
+        {
+            tryLogCurrentException(__PRETTY_FUNCTION__);
+        }
+    }
+
+    void finalize() override
+    {
+        if (finalized)
+            return;
+
+        WriteBufferFromFileDecorator::finalize();
+
+        lock.unlock();
+    }
+
+private:
+    ReadLock lock;
+};
+
+DiskRestartProxy::DiskRestartProxy(DiskPtr & delegate_)
+    : DiskDecorator(delegate_) { }
+
+ReservationPtr DiskRestartProxy::reserve(UInt64 bytes)
+{
+    ReadLock lock (mutex);
+    auto ptr = DiskDecorator::reserve(bytes);
+    if (ptr)
+    {
+        auto disk_ptr = std::static_pointer_cast<DiskRestartProxy>(shared_from_this());
+        return std::make_unique<ReservationDelegate>(std::move(ptr), disk_ptr);
+    }
+    return ptr;
+}
+
+const String & DiskRestartProxy::getPath() const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::getPath();
+}
+
+UInt64 DiskRestartProxy::getTotalSpace() const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::getTotalSpace();
+}
+
+UInt64 DiskRestartProxy::getAvailableSpace() const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::getAvailableSpace();
+}
+
+UInt64 DiskRestartProxy::getUnreservedSpace() const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::getUnreservedSpace();
+}
+
+UInt64 DiskRestartProxy::getKeepingFreeSpace() const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::getKeepingFreeSpace();
+}
+
+bool DiskRestartProxy::exists(const String & path) const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::exists(path);
+}
+
+bool DiskRestartProxy::isFile(const String & path) const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::isFile(path);
+}
+
+bool DiskRestartProxy::isDirectory(const String & path) const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::isDirectory(path);
+}
+
+size_t DiskRestartProxy::getFileSize(const String & path) const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::getFileSize(path);
+}
+
+void DiskRestartProxy::createDirectory(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::createDirectory(path);
+}
+
+void DiskRestartProxy::createDirectories(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::createDirectories(path);
+}
+
+void DiskRestartProxy::clearDirectory(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::clearDirectory(path);
+}
+
+void DiskRestartProxy::moveDirectory(const String & from_path, const String & to_path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::moveDirectory(from_path, to_path);
+}
+
+DiskDirectoryIteratorPtr DiskRestartProxy::iterateDirectory(const String & path)
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::iterateDirectory(path);
+}
+
+void DiskRestartProxy::createFile(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::createFile(path);
+}
+
+void DiskRestartProxy::moveFile(const String & from_path, const String & to_path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::moveFile(from_path, to_path);
+}
+
+void DiskRestartProxy::replaceFile(const String & from_path, const String & to_path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::replaceFile(from_path, to_path);
+}
+
+void DiskRestartProxy::copy(const String & from_path, const std::shared_ptr<IDisk> & to_disk, const String & to_path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::copy(from_path, to_disk, to_path);
+}
+
+void DiskRestartProxy::listFiles(const String & path, std::vector<String> & file_names)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::listFiles(path, file_names);
+}
+
+std::unique_ptr<ReadBufferFromFileBase> DiskRestartProxy::readFile(
+    const String & path, size_t buf_size, size_t estimated_size, size_t aio_threshold, size_t mmap_threshold, MMappedFileCache * mmap_cache)
+    const
+{
+    ReadLock lock (mutex);
+    auto impl = DiskDecorator::readFile(path, buf_size, estimated_size, aio_threshold, mmap_threshold, mmap_cache);
+    return std::make_unique<RestartAwareReadBuffer>(*this, std::move(impl));
+}
+
+std::unique_ptr<WriteBufferFromFileBase> DiskRestartProxy::writeFile(const String & path, size_t buf_size, WriteMode mode)
+{
+    ReadLock lock (mutex);
+    auto impl = DiskDecorator::writeFile(path, buf_size, mode);
+    return std::make_unique<RestartAwareWriteBuffer>(*this, std::move(impl));
+}
+
+void DiskRestartProxy::removeFile(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::removeFile(path);
+}
+
+void DiskRestartProxy::removeFileIfExists(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::removeFileIfExists(path);
+}
+
+void DiskRestartProxy::removeDirectory(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::removeDirectory(path);
+}
+
+void DiskRestartProxy::removeRecursive(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::removeRecursive(path);
+}
+
+void DiskRestartProxy::removeSharedFile(const String & path, bool keep_s3)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::removeSharedFile(path, keep_s3);
+}
+
+void DiskRestartProxy::removeSharedRecursive(const String & path, bool keep_s3)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::removeSharedRecursive(path, keep_s3);
+}
+
+void DiskRestartProxy::setLastModified(const String & path, const Poco::Timestamp & timestamp)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::setLastModified(path, timestamp);
+}
+
+Poco::Timestamp DiskRestartProxy::getLastModified(const String & path)
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::getLastModified(path);
+}
+
+void DiskRestartProxy::setReadOnly(const String & path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::setReadOnly(path);
+}
+
+void DiskRestartProxy::createHardLink(const String & src_path, const String & dst_path)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::createHardLink(src_path, dst_path);
+}
+
+void DiskRestartProxy::truncateFile(const String & path, size_t size)
+{
+    ReadLock lock (mutex);
+    DiskDecorator::truncateFile(path, size);
+}
+
+String DiskRestartProxy::getUniqueId(const String & path) const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::getUniqueId(path);
+}
+
+bool DiskRestartProxy::checkUniqueId(const String & id) const
+{
+    ReadLock lock (mutex);
+    return DiskDecorator::checkUniqueId(id);
+}
+
+void DiskRestartProxy::restart()
+{
+    /// Speed up processing unhealthy requests.
+    DiskDecorator::shutdown();
+
+    WriteLock lock (mutex, std::defer_lock);
+
+    LOG_INFO(log, "Acquiring lock to restart disk {}", DiskDecorator::getName());
+
+    auto start_time = std::chrono::steady_clock::now();
+    auto lock_timeout = Seconds(120);
+    do
+    {
+        /// Use a small timeout to not block read operations for a long time.
+        if (lock.try_lock_for(Millis(10)))
+            break;
+    } while (std::chrono::steady_clock::now() - start_time < lock_timeout);
+
+    if (!lock.owns_lock())
+        throw Exception("Failed to acquire restart lock within timeout. Client should retry.", ErrorCodes::DEADLOCK_AVOIDED);
+
+    LOG_INFO(log, "Restart lock acquired. Restarting disk {}", DiskDecorator::getName());
+
+    DiskDecorator::startup();
+
+    LOG_INFO(log, "Disk restarted {}", DiskDecorator::getName());
+}
+
+}
--- a/src/Disks/DiskRestartProxy.h
+++ b/src/Disks/DiskRestartProxy.h
@ -0,0 +1,80 @@
+#pragma once
+
+#include "DiskDecorator.h"
+
+#include <common/logger_useful.h>
+#include <shared_mutex>
+
+namespace DB
+{
+using ReadLock = std::shared_lock<std::shared_timed_mutex>;
+using WriteLock = std::unique_lock<std::shared_timed_mutex>;
+
+class RestartAwareReadBuffer;
+class RestartAwareWriteBuffer;
+
+/**
+ * Gives possibility to change underlying disk settings at runtime calling 'restart' method.
+ * All disk methods are protected by read-lock. Read/Write buffers produced by disk holds read-lock till buffer is finalized/destructed.
+ * When 'restart' method is called write-lock is acquired to make sure that no operations are running on that disk.
+ */
+class DiskRestartProxy : public DiskDecorator
+{
+public:
+    explicit DiskRestartProxy(DiskPtr & delegate_);
+
+    ReservationPtr reserve(UInt64 bytes) override;
+    const String & getPath() const override;
+    UInt64 getTotalSpace() const override;
+    UInt64 getAvailableSpace() const override;
+    UInt64 getUnreservedSpace() const override;
+    UInt64 getKeepingFreeSpace() const override;
+    bool exists(const String & path) const override;
+    bool isFile(const String & path) const override;
+    bool isDirectory(const String & path) const override;
+    size_t getFileSize(const String & path) const override;
+    void createDirectory(const String & path) override;
+    void createDirectories(const String & path) override;
+    void clearDirectory(const String & path) override;
+    void moveDirectory(const String & from_path, const String & to_path) override;
+    DiskDirectoryIteratorPtr iterateDirectory(const String & path) override;
+    void createFile(const String & path) override;
+    void moveFile(const String & from_path, const String & to_path) override;
+    void replaceFile(const String & from_path, const String & to_path) override;
+    void copy(const String & from_path, const DiskPtr & to_disk, const String & to_path) override;
+    void listFiles(const String & path, std::vector<String> & file_names) override;
+    std::unique_ptr<ReadBufferFromFileBase> readFile(
+        const String & path,
+        size_t buf_size,
+        size_t estimated_size,
+        size_t aio_threshold,
+        size_t mmap_threshold,
+        MMappedFileCache * mmap_cache) const override;
+    std::unique_ptr<WriteBufferFromFileBase> writeFile(const String & path, size_t buf_size, WriteMode mode) override;
+    void removeFile(const String & path) override;
+    void removeFileIfExists(const String & path) override;
+    void removeDirectory(const String & path) override;
+    void removeRecursive(const String & path) override;
+    void removeSharedFile(const String & path, bool keep_s3) override;
+    void removeSharedRecursive(const String & path, bool keep_s3) override;
+    void setLastModified(const String & path, const Poco::Timestamp & timestamp) override;
+    Poco::Timestamp getLastModified(const String & path) override;
+    void setReadOnly(const String & path) override;
+    void createHardLink(const String & src_path, const String & dst_path) override;
+    void truncateFile(const String & path, size_t size) override;
+    String getUniqueId(const String & path) const override;
+    bool checkUniqueId(const String & id) const override;
+
+    void restart();
+
+private:
+    friend class RestartAwareReadBuffer;
+    friend class RestartAwareWriteBuffer;
+
+    /// Mutex to protect RW access.
+    mutable std::shared_timed_mutex mutex;
+
+    Poco::Logger * log = &Poco::Logger::get("DiskRestartProxy");
+};
+
+}
--- a/src/Disks/DiskSelector.cpp
+++ b/src/Disks/DiskSelector.cpp
@ -55,11 +55,7 @@ DiskSelectorPtr DiskSelector::updateFromConfig(
    std::shared_ptr<DiskSelector> result = std::make_shared<DiskSelector>(*this);

    constexpr auto default_disk_name = "default";
-    std::set<String> old_disks_minus_new_disks;
-    for (const auto & [disk_name, _] : result->getDisksMap())
-    {
-        old_disks_minus_new_disks.insert(disk_name);
-    }
+    DisksMap old_disks_minus_new_disks (result->getDisksMap());

    for (const auto & disk_name : keys)
    {
@ -73,10 +69,11 @@ DiskSelectorPtr DiskSelector::updateFromConfig(
        }
        else
        {
-            old_disks_minus_new_disks.erase(disk_name);
+            auto disk = old_disks_minus_new_disks[disk_name];

-            /// TODO: Ideally ClickHouse shall complain if disk has changed, but
-            /// implementing that may appear as not trivial task.
+            disk->applyNewSettings(config, context);
+
+            old_disks_minus_new_disks.erase(disk_name);
        }
    }

@ -91,7 +88,7 @@ DiskSelectorPtr DiskSelector::updateFromConfig(
            writeString("Disks ", warning);

        int index = 0;
-        for (const String & name : old_disks_minus_new_disks)
+        for (const auto & [name, _] : old_disks_minus_new_disks)
        {
            if (index++ > 0)
                writeString(", ", warning);
--- a/src/Disks/IDisk.h
+++ b/src/Disks/IDisk.h
@ -1,5 +1,6 @@
 #pragma once

+#include <Interpreters/Context_fwd.h>
 #include <Core/Defines.h>
 #include <common/types.h>
 #include <Common/CurrentMetrics.h>
@ -13,6 +14,7 @@
 #include <boost/noncopyable.hpp>
 #include <Poco/Path.h>
 #include <Poco/Timestamp.h>
+#include "Poco/Util/AbstractConfiguration.h"


 namespace CurrentMetrics
@ -211,24 +213,33 @@ public:
    /// Invoked when Global Context is shutdown.
    virtual void shutdown() { }

+    /// Performs action on disk startup.
+    virtual void startup() { }
+
    /// Return some uniq string for file, overrode for S3
    /// Required for distinguish different copies of the same part on S3
    virtual String getUniqueId(const String & path) const { return path; }

    /// Check file exists and ClickHouse has an access to it
    /// Overrode in DiskS3
-    /// Required for S3 to ensure that replica has access to data wroten by other node
+    /// Required for S3 to ensure that replica has access to data written by other node
    virtual bool checkUniqueId(const String & id) const { return exists(id); }

-    /// Returns executor to perform asynchronous operations.
-    virtual Executor & getExecutor() { return *executor; }
-
    /// Invoked on partitions freeze query.
    virtual void onFreeze(const String &) { }

    /// Returns guard, that insures synchronization of directory metadata with storage device.
    virtual SyncGuardPtr getDirectorySyncGuard(const String & path) const;

+    /// Applies new settings for disk in runtime.
+    virtual void applyNewSettings(const Poco::Util::AbstractConfiguration &, ContextConstPtr) { }
+
+protected:
+    friend class DiskDecorator;
+
+    /// Returns executor to perform asynchronous operations.
+    virtual Executor & getExecutor() { return *executor; }
+
 private:
    std::unique_ptr<Executor> executor;
 };
--- a/src/Disks/S3/DiskS3.cpp
+++ b/src/Disks/S3/DiskS3.cpp
@ -7,11 +7,13 @@
 #include <optional>
 #include <utility>
 #include <IO/ReadBufferFromString.h>
+#include <Interpreters/Context.h>
 #include <IO/ReadBufferFromFile.h>
 #include <IO/ReadBufferFromS3.h>
 #include <IO/ReadHelpers.h>
 #include <IO/SeekAvoidingReadBuffer.h>
 #include <IO/WriteBufferFromFile.h>
+#include <IO/WriteBufferFromFileDecorator.h>
 #include <IO/WriteBufferFromS3.h>
 #include <IO/WriteHelpers.h>
 #include <Poco/File.h>
@ -235,6 +237,28 @@ struct DiskS3::Metadata
    }
 };

+DiskS3::Metadata DiskS3::readOrCreateMetaForWriting(const String & path, WriteMode mode)
+{
+    bool exist = exists(path);
+    if (exist)
+    {
+        auto metadata = readMeta(path);
+        if (metadata.read_only)
+            throw Exception("File is read-only: " + path, ErrorCodes::PATH_ACCESS_DENIED);
+
+        if (mode == WriteMode::Rewrite)
+            removeFile(path); /// Remove for re-write.
+        else
+            return metadata;
+    }
+
+    auto metadata = createMeta(path);
+    /// Save empty metadata to disk to have ability to get file size while buffer is not finalized.
+    metadata.save();
+
+    return metadata;
+}
+
 DiskS3::Metadata DiskS3::readMeta(const String & path) const
 {
    return Metadata(s3_root_path, metadata_path, path);
@ -250,7 +274,11 @@ class ReadIndirectBufferFromS3 final : public ReadBufferFromFileBase
 {
 public:
    ReadIndirectBufferFromS3(
-        std::shared_ptr<Aws::S3::S3Client> client_ptr_, const String & bucket_, DiskS3::Metadata metadata_, UInt64 s3_max_single_read_retries_, size_t buf_size_)
+        std::shared_ptr<Aws::S3::S3Client> client_ptr_,
+        const String & bucket_,
+        DiskS3::Metadata metadata_,
+        size_t s3_max_single_read_retries_,
+        size_t buf_size_)
        : client_ptr(std::move(client_ptr_))
        , bucket(bucket_)
        , metadata(std::move(metadata_))
@ -351,7 +379,7 @@ private:
    std::shared_ptr<Aws::S3::S3Client> client_ptr;
    const String & bucket;
    DiskS3::Metadata metadata;
-    UInt64 s3_max_single_read_retries;
+    size_t s3_max_single_read_retries;
    size_t buf_size;

    size_t absolute_position = 0;
@ -360,30 +388,22 @@ private:
 };

 /// Stores data in S3 and adds the object key (S3 path) and object size to metadata file on local FS.
-class WriteIndirectBufferFromS3 final : public WriteBufferFromFileBase
+class WriteIndirectBufferFromS3 final : public WriteBufferFromFileDecorator
 {
 public:
    WriteIndirectBufferFromS3(
-        std::shared_ptr<Aws::S3::S3Client> & client_ptr_,
-        const String & bucket_,
+        std::unique_ptr<WriteBufferFromS3> impl_,
        DiskS3::Metadata metadata_,
-        const String & s3_path_,
-        std::optional<DiskS3::ObjectMetadata> object_metadata_,
-        size_t min_upload_part_size,
-        size_t max_single_part_upload_size,
-        size_t buf_size_)
-        : WriteBufferFromFileBase(buf_size_, nullptr, 0)
-        , impl(WriteBufferFromS3(client_ptr_, bucket_, metadata_.s3_root_path + s3_path_, min_upload_part_size, max_single_part_upload_size,std::move(object_metadata_), buf_size_))
+        String & s3_path_)
+        : WriteBufferFromFileDecorator(std::move(impl_))
        , metadata(std::move(metadata_))
-        , s3_path(s3_path_)
-    {
-    }
+        , s3_path(s3_path_) { }

-    ~WriteIndirectBufferFromS3() override
+    virtual ~WriteIndirectBufferFromS3() override
    {
        try
        {
-            finalize();
+            WriteIndirectBufferFromS3::finalize();
        }
        catch (...)
        {
@ -396,13 +416,10 @@ public:
        if (finalized)
            return;

-        next();
-        impl.finalize();
+        WriteBufferFromFileDecorator::finalize();

        metadata.addObject(s3_path, count());
        metadata.save();
-
-        finalized = true;
    }

    void sync() override
@ -414,20 +431,6 @@ public:
    std::string getFileName() const override { return metadata.metadata_file_path; }

 private:
-    void nextImpl() override
-    {
-        /// Transfer current working buffer to WriteBufferFromS3.
-        impl.swap(*this);
-
-        /// Write actual data to S3.
-        impl.next();
-
-        /// Return back working buffer.
-        impl.swap(*this);
-    }
-
-    WriteBufferFromS3 impl;
-    bool finalized = false;
    DiskS3::Metadata metadata;
    String s3_path;
 };
@ -530,7 +533,6 @@ public:
    std::future<void> execute(std::function<void()> task) override
    {
        auto promise = std::make_shared<std::promise<void>>();
-
        pool.scheduleOrThrowOnError(
            [promise, task]()
            {
@ -553,6 +555,10 @@ public:
        return promise->get_future();
    }

+    void setMaxThreads(size_t threads)
+    {
+        pool.setMaxThreads(threads);
+    }
 private:
    ThreadPool pool;
 };
@ -560,32 +566,18 @@ private:

 DiskS3::DiskS3(
    String name_,
-    std::shared_ptr<Aws::S3::S3Client> client_,
-    std::shared_ptr<S3::ProxyConfiguration> proxy_configuration_,
    String bucket_,
    String s3_root_path_,
    String metadata_path_,
-    UInt64 s3_max_single_read_retries_,
-    size_t min_upload_part_size_,
-    size_t max_single_part_upload_size_,
-    size_t min_bytes_for_seek_,
-    bool send_metadata_,
-    int thread_pool_size_,
-    int list_object_keys_size_)
-    : IDisk(std::make_unique<AsyncExecutor>(thread_pool_size_))
+    SettingsPtr settings_,
+    GetDiskSettings settings_getter_)
+    : IDisk(std::make_unique<AsyncExecutor>(settings_->thread_pool_size))
    , name(std::move(name_))
-    , client(std::move(client_))
-    , proxy_configuration(std::move(proxy_configuration_))
    , bucket(std::move(bucket_))
    , s3_root_path(std::move(s3_root_path_))
    , metadata_path(std::move(metadata_path_))
-    , s3_max_single_read_retries(s3_max_single_read_retries_)
-    , min_upload_part_size(min_upload_part_size_)
-    , max_single_part_upload_size(max_single_part_upload_size_)
-    , min_bytes_for_seek(min_bytes_for_seek_)
-    , send_metadata(send_metadata_)
-    , revision_counter(0)
-    , list_object_keys_size(list_object_keys_size_)
+    , current_settings(std::move(settings_))
+    , settings_getter(settings_getter_)
 {
 }

@ -649,6 +641,13 @@ void DiskS3::clearDirectory(const String & path)
 }

 void DiskS3::moveFile(const String & from_path, const String & to_path)
+{
+    auto settings = current_settings.get();
+
+    moveFile(from_path, to_path, settings->send_metadata);
+}
+
+void DiskS3::moveFile(const String & from_path, const String & to_path, bool send_metadata)
 {
    if (exists(to_path))
        throw Exception("File already exists: " + to_path, ErrorCodes::FILE_ALREADY_EXISTS);
@ -681,26 +680,26 @@ void DiskS3::replaceFile(const String & from_path, const String & to_path)

 std::unique_ptr<ReadBufferFromFileBase> DiskS3::readFile(const String & path, size_t buf_size, size_t, size_t, size_t, MMappedFileCache *) const
 {
+    auto settings = current_settings.get();
    auto metadata = readMeta(path);

    LOG_DEBUG(log, "Read from file by path: {}. Existing S3 objects: {}",
        backQuote(metadata_path + path), metadata.s3_objects.size());

-    auto reader = std::make_unique<ReadIndirectBufferFromS3>(client, bucket, metadata, s3_max_single_read_retries, buf_size);
-    return std::make_unique<SeekAvoidingReadBuffer>(std::move(reader), min_bytes_for_seek);
+    auto reader = std::make_unique<ReadIndirectBufferFromS3>(settings->client, bucket, metadata, settings->s3_max_single_read_retries, buf_size);
+    return std::make_unique<SeekAvoidingReadBuffer>(std::move(reader), settings->min_bytes_for_seek);
 }

 std::unique_ptr<WriteBufferFromFileBase> DiskS3::writeFile(const String & path, size_t buf_size, WriteMode mode)
 {
-    bool exist = exists(path);
-    if (exist && readMeta(path).read_only)
-        throw Exception("File is read-only: " + path, ErrorCodes::PATH_ACCESS_DENIED);
+    auto settings = current_settings.get();
+    auto metadata = readOrCreateMetaForWriting(path, mode);

    /// Path to store new S3 object.
    auto s3_path = getRandomName();

    std::optional<ObjectMetadata> object_metadata;
-    if (send_metadata)
+    if (settings->send_metadata)
    {
        auto revision = ++revision_counter;
        object_metadata = {
@ -709,31 +708,19 @@ std::unique_ptr<WriteBufferFromFileBase> DiskS3::writeFile(const String & path,
        s3_path = "r" + revisionToString(revision) + "-file-" + s3_path;
    }

-    if (!exist || mode == WriteMode::Rewrite)
-    {
-        /// If metadata file exists - remove and create new.
-        if (exist)
-            removeFile(path);
+    LOG_DEBUG(log, "{} to file by path: {}. S3 path: {}",
+              mode == WriteMode::Rewrite ? "Write" : "Append", backQuote(metadata_path + path), s3_root_path + s3_path);

-        auto metadata = createMeta(path);
-        /// Save empty metadata to disk to have ability to get file size while buffer is not finalized.
-        metadata.save();
+    auto s3_buffer = std::make_unique<WriteBufferFromS3>(
+        settings->client,
+        bucket,
+        metadata.s3_root_path + s3_path,
+        settings->s3_min_upload_part_size,
+        settings->s3_max_single_part_upload_size,
+        std::move(object_metadata),
+        buf_size);

-        LOG_DEBUG(log, "Write to file by path: {}. New S3 path: {}", backQuote(metadata_path + path), s3_root_path + s3_path);
-
-        return std::make_unique<WriteIndirectBufferFromS3>(
-            client, bucket, metadata, s3_path, object_metadata, min_upload_part_size, max_single_part_upload_size, buf_size);
-    }
-    else
-    {
-        auto metadata = readMeta(path);
-
-        LOG_DEBUG(log, "Append to file by path: {}. New S3 path: {}. Existing S3 objects: {}.",
-            backQuote(metadata_path + path), s3_root_path + s3_path, metadata.s3_objects.size());
-
-        return std::make_unique<WriteIndirectBufferFromS3>(
-            client, bucket, metadata, s3_path, object_metadata, min_upload_part_size, max_single_part_upload_size, buf_size);
-    }
+    return std::make_unique<WriteIndirectBufferFromS3>(std::move(s3_buffer), std::move(metadata), s3_path);
 }

 void DiskS3::removeMeta(const String & path, AwsS3KeyKeeper & keys)
@ -803,6 +790,8 @@ void DiskS3::removeAws(const AwsS3KeyKeeper & keys)
 {
    if (!keys.empty())
    {
+        auto settings = current_settings.get();
+
        for (const auto & chunk : keys)
        {
            Aws::S3::Model::Delete delkeys;
@ -812,7 +801,7 @@ void DiskS3::removeAws(const AwsS3KeyKeeper & keys)
            Aws::S3::Model::DeleteObjectsRequest request;
            request.SetBucket(bucket);
            request.SetDelete(delkeys);
-            auto outcome = client->DeleteObjects(request);
+            auto outcome = settings->client->DeleteObjects(request);
            throwIfError(outcome);
        }
    }
@ -889,6 +878,13 @@ Poco::Timestamp DiskS3::getLastModified(const String & path)
 }

 void DiskS3::createHardLink(const String & src_path, const String & dst_path)
+{
+    auto settings = current_settings.get();
+
+    createHardLink(src_path, dst_path, settings->send_metadata);
+}
+
+void DiskS3::createHardLink(const String & src_path, const String & dst_path, bool send_metadata)
 {
    /// We don't need to record hardlinks created to shadow folder.
    if (send_metadata && !dst_path.starts_with("shadow/"))
@ -928,28 +924,41 @@ void DiskS3::setReadOnly(const String & path)

 void DiskS3::shutdown()
 {
+    auto settings = current_settings.get();
    /// This call stops any next retry attempts for ongoing S3 requests.
    /// If S3 request is failed and the method below is executed S3 client immediately returns the last failed S3 request outcome.
    /// If S3 is healthy nothing wrong will be happened and S3 requests will be processed in a regular way without errors.
    /// This should significantly speed up shutdown process if S3 is unhealthy.
-    client->DisableRequestProcessing();
+    settings->client->DisableRequestProcessing();
 }

 void DiskS3::createFileOperationObject(const String & operation_name, UInt64 revision, const DiskS3::ObjectMetadata & metadata)
 {
+    auto settings = current_settings.get();
    const String key = "operations/r" + revisionToString(revision) + "-" + operation_name;
-    WriteBufferFromS3 buffer(client, bucket, s3_root_path + key, min_upload_part_size, max_single_part_upload_size, metadata);
+    WriteBufferFromS3 buffer(
+        settings->client,
+        bucket,
+        s3_root_path + key,
+        settings->s3_min_upload_part_size,
+        settings->s3_max_single_part_upload_size,
+        metadata);
+
    buffer.write('0');
    buffer.finalize();
 }

 void DiskS3::startup()
 {
-    if (!send_metadata)
+    auto settings = current_settings.get();
+
+    if (!settings->send_metadata)
        return;

    LOG_INFO(log, "Starting up disk {}", name);

+    restore();
+
    if (readSchemaVersion(bucket, s3_root_path) < RESTORABLE_SCHEMA_VERSION)
        migrateToRestorableSchema();

@ -986,7 +995,13 @@ int DiskS3::readSchemaVersion(const String & source_bucket, const String & sourc
    if (!checkObjectExists(source_bucket, source_path + SCHEMA_VERSION_OBJECT))
        return version;

-    ReadBufferFromS3 buffer(client, source_bucket, source_path + SCHEMA_VERSION_OBJECT, s3_max_single_read_retries);
+    auto settings = current_settings.get();
+    ReadBufferFromS3 buffer(
+        settings->client,
+        source_bucket,
+        source_path + SCHEMA_VERSION_OBJECT,
+        settings->s3_max_single_read_retries);
+
    readIntText(version, buffer);

    return version;
@ -994,13 +1009,22 @@ int DiskS3::readSchemaVersion(const String & source_bucket, const String & sourc

 void DiskS3::saveSchemaVersion(const int & version)
 {
-    WriteBufferFromS3 buffer (client, bucket, s3_root_path + SCHEMA_VERSION_OBJECT, min_upload_part_size, max_single_part_upload_size);
+    auto settings = current_settings.get();
+
+    WriteBufferFromS3 buffer(
+        settings->client,
+        bucket,
+        s3_root_path + SCHEMA_VERSION_OBJECT,
+        settings->s3_min_upload_part_size,
+        settings->s3_max_single_part_upload_size);
+
    writeIntText(version, buffer);
    buffer.finalize();
 }

 void DiskS3::updateObjectMetadata(const String & key, const ObjectMetadata & metadata)
 {
+    auto settings = current_settings.get();
    Aws::S3::Model::CopyObjectRequest request;
    request.SetCopySource(bucket + "/" + key);
    request.SetBucket(bucket);
@ -1008,7 +1032,7 @@ void DiskS3::updateObjectMetadata(const String & key, const ObjectMetadata & met
    request.SetMetadata(metadata);
    request.SetMetadataDirective(Aws::S3::Model::MetadataDirective::REPLACE);

-    auto outcome = client->CopyObject(request);
+    auto outcome = settings->client->CopyObject(request);
    throwIfError(outcome);
 }

@ -1097,14 +1121,15 @@ void DiskS3::migrateToRestorableSchema()
    }
 }

-bool DiskS3::checkObjectExists(const String & source_bucket, const String & prefix)
+bool DiskS3::checkObjectExists(const String & source_bucket, const String & prefix) const
 {
+    auto settings = current_settings.get();
    Aws::S3::Model::ListObjectsV2Request request;
    request.SetBucket(source_bucket);
    request.SetPrefix(prefix);
    request.SetMaxKeys(1);

-    auto outcome = client->ListObjectsV2(request);
+    auto outcome = settings->client->ListObjectsV2(request);
    throwIfError(outcome);

    return !outcome.GetResult().GetContents().empty();
@ -1112,12 +1137,13 @@ bool DiskS3::checkObjectExists(const String & source_bucket, const String & pref

 bool DiskS3::checkUniqueId(const String & id) const
 {
+    auto settings = current_settings.get();
    /// Check that we have right s3 and have access rights
    /// Actually interprets id as s3 object name and checks if it exists
    Aws::S3::Model::ListObjectsV2Request request;
    request.SetBucket(bucket);
    request.SetPrefix(id);
-    auto resp = client->ListObjectsV2(request);
+    auto resp = settings->client->ListObjectsV2(request);
    throwIfError(resp);
    Aws::Vector<Aws::S3::Model::Object> object_list = resp.GetResult().GetContents();

@ -1127,29 +1153,31 @@ bool DiskS3::checkUniqueId(const String & id) const
    return false;
 }

-Aws::S3::Model::HeadObjectResult DiskS3::headObject(const String & source_bucket, const String & key)
+Aws::S3::Model::HeadObjectResult DiskS3::headObject(const String & source_bucket, const String & key) const
 {
+    auto settings = current_settings.get();
    Aws::S3::Model::HeadObjectRequest request;
    request.SetBucket(source_bucket);
    request.SetKey(key);

-    auto outcome = client->HeadObject(request);
+    auto outcome = settings->client->HeadObject(request);
    throwIfError(outcome);

    return outcome.GetResultWithOwnership();
 }

-void DiskS3::listObjects(const String & source_bucket, const String & source_path, std::function<bool(const Aws::S3::Model::ListObjectsV2Result &)> callback)
+void DiskS3::listObjects(const String & source_bucket, const String & source_path, std::function<bool(const Aws::S3::Model::ListObjectsV2Result &)> callback) const
 {
+    auto settings = current_settings.get();
    Aws::S3::Model::ListObjectsV2Request request;
    request.SetBucket(source_bucket);
    request.SetPrefix(source_path);
-    request.SetMaxKeys(list_object_keys_size);
+    request.SetMaxKeys(settings->list_object_keys_size);

    Aws::S3::Model::ListObjectsV2Outcome outcome;
    do
    {
-        outcome = client->ListObjectsV2(request);
+        outcome = settings->client->ListObjectsV2(request);
        throwIfError(outcome);

        bool should_continue = callback(outcome.GetResult());
@ -1161,14 +1189,15 @@ void DiskS3::listObjects(const String & source_bucket, const String & source_pat
    } while (outcome.GetResult().GetIsTruncated());
 }

-void DiskS3::copyObject(const String & src_bucket, const String & src_key, const String & dst_bucket, const String & dst_key)
+void DiskS3::copyObject(const String & src_bucket, const String & src_key, const String & dst_bucket, const String & dst_key) const
 {
+    auto settings = current_settings.get();
    Aws::S3::Model::CopyObjectRequest request;
    request.SetCopySource(src_bucket + "/" + src_key);
    request.SetBucket(dst_bucket);
    request.SetKey(dst_key);

-    auto outcome = client->CopyObject(request);
+    auto outcome = settings->client->CopyObject(request);
    throwIfError(outcome);
 }

@ -1375,13 +1404,15 @@ void DiskS3::processRestoreFiles(const String & source_bucket, const String & so

 void DiskS3::restoreFileOperations(const RestoreInformation & restore_information)
 {
+    auto settings = current_settings.get();
+
    LOG_INFO(log, "Starting restore file operations for disk {}", name);

    /// Enable recording file operations if we restore to different bucket / path.
-    send_metadata = bucket != restore_information.source_bucket || s3_root_path != restore_information.source_path;
+    bool send_metadata = bucket != restore_information.source_bucket || s3_root_path != restore_information.source_path;

    std::set<String> renames;
-    auto restore_file_operations = [this, &restore_information, &renames](auto list_result)
+    auto restore_file_operations = [this, &restore_information, &renames, &send_metadata](auto list_result)
    {
        const String rename = "rename";
        const String hardlink = "hardlink";
@ -1413,7 +1444,7 @@ void DiskS3::restoreFileOperations(const RestoreInformation & restore_informatio
                auto to_path = object_metadata["to_path"];
                if (exists(from_path))
                {
-                    moveFile(from_path, to_path);
+                    moveFile(from_path, to_path, send_metadata);
                    LOG_DEBUG(log, "Revision {}. Restored rename {} -> {}", revision, from_path, to_path);

                    if (restore_information.detached && isDirectory(to_path))
@ -1440,7 +1471,7 @@ void DiskS3::restoreFileOperations(const RestoreInformation & restore_informatio
                if (exists(src_path))
                {
                    createDirectories(directoryPath(dst_path));
-                    createHardLink(src_path, dst_path);
+                    createHardLink(src_path, dst_path, send_metadata);
                    LOG_DEBUG(log, "Revision {}. Restored hardlink {} -> {}", revision, src_path, dst_path);
                }
            }
@ -1477,8 +1508,6 @@ void DiskS3::restoreFileOperations(const RestoreInformation & restore_informatio
        }
    }

-    send_metadata = true;
-
    LOG_INFO(log, "File operations restored for disk {}", name);
 }

@ -1518,4 +1547,34 @@ void DiskS3::onFreeze(const String & path)
    revision_file_buf.finalize();
 }

+void DiskS3::applyNewSettings(const Poco::Util::AbstractConfiguration & config, ContextConstPtr context)
+{
+    auto new_settings = settings_getter(config, "storage_configuration.disks." + name, context);
+
+    current_settings.set(std::move(new_settings));
+
+    if (AsyncExecutor * exec = dynamic_cast<AsyncExecutor*>(&getExecutor()))
+        exec->setMaxThreads(current_settings.get()->thread_pool_size);
+}
+
+DiskS3Settings::DiskS3Settings(
+    const std::shared_ptr<Aws::S3::S3Client> & client_,
+    size_t s3_max_single_read_retries_,
+    size_t s3_min_upload_part_size_,
+    size_t s3_max_single_part_upload_size_,
+    size_t min_bytes_for_seek_,
+    bool send_metadata_,
+    int thread_pool_size_,
+    int list_object_keys_size_)
+    : client(client_)
+    , s3_max_single_read_retries(s3_max_single_read_retries_)
+    , s3_min_upload_part_size(s3_min_upload_part_size_)
+    , s3_max_single_part_upload_size(s3_max_single_part_upload_size_)
+    , min_bytes_for_seek(min_bytes_for_seek_)
+    , send_metadata(send_metadata_)
+    , thread_pool_size(thread_pool_size_)
+    , list_object_keys_size(list_object_keys_size_)
+{
+}
+
 }
--- a/src/Disks/S3/DiskS3.h
+++ b/src/Disks/S3/DiskS3.h
@ -2,9 +2,9 @@

 #include <atomic>
 #include <common/logger_useful.h>
+#include <Common/MultiVersion.h>
 #include "Disks/DiskFactory.h"
 #include "Disks/Executor.h"
-#include "ProxyConfiguration.h"

 #include <aws/s3/S3Client.h>
 #include <aws/s3/model/HeadObjectResult.h>
@ -17,6 +17,29 @@
 namespace DB
 {

+/// Settings for DiskS3 that can be changed in runtime.
+struct DiskS3Settings
+{
+    DiskS3Settings(
+        const std::shared_ptr<Aws::S3::S3Client> & client_,
+        size_t s3_max_single_read_retries_,
+        size_t s3_min_upload_part_size_,
+        size_t s3_max_single_part_upload_size_,
+        size_t min_bytes_for_seek_,
+        bool send_metadata_,
+        int thread_pool_size_,
+        int list_object_keys_size_);
+
+    std::shared_ptr<Aws::S3::S3Client> client;
+    size_t s3_max_single_read_retries;
+    size_t s3_min_upload_part_size;
+    size_t s3_max_single_part_upload_size;
+    size_t min_bytes_for_seek;
+    bool send_metadata;
+    int thread_pool_size;
+    int list_object_keys_size;
+};
+
 /**
 * Storage for persisting data in S3 and metadata on the local disk.
 * Files are represented by file in local filesystem (clickhouse_root/disks/disk_name/path/to/file)
@ -27,6 +50,8 @@ class DiskS3 : public IDisk
 public:
    using ObjectMetadata = std::map<std::string, std::string>;
    using Futures = std::vector<std::future<void>>;
+    using SettingsPtr = std::unique_ptr<DiskS3Settings>;
+    using GetDiskSettings = std::function<SettingsPtr(const Poco::Util::AbstractConfiguration &, const String, ContextConstPtr)>;

    friend class DiskS3Reservation;

@ -36,18 +61,11 @@ public:

    DiskS3(
        String name_,
-        std::shared_ptr<Aws::S3::S3Client> client_,
-        std::shared_ptr<S3::ProxyConfiguration> proxy_configuration_,
        String bucket_,
        String s3_root_path_,
        String metadata_path_,
-        UInt64 s3_max_single_read_retries_,
-        size_t min_upload_part_size_,
-        size_t max_single_part_upload_size_,
-        size_t min_bytes_for_seek_,
-        bool send_metadata_,
-        int thread_pool_size_,
-        int list_object_keys_size_);
+        SettingsPtr settings_,
+        GetDiskSettings settings_getter_);

    const String & getName() const override { return name; }

@ -82,7 +100,7 @@ public:
    DiskDirectoryIteratorPtr iterateDirectory(const String & path) override;

    void moveFile(const String & from_path, const String & to_path) override;
-
+    void moveFile(const String & from_path, const String & to_path, bool send_metadata);
    void replaceFile(const String & from_path, const String & to_path) override;

    void listFiles(const String & path, std::vector<String> & file_names) override;
@ -109,6 +127,7 @@ public:
    void removeSharedRecursive(const String & path, bool keep_s3) override;

    void createHardLink(const String & src_path, const String & dst_path) override;
+    void createHardLink(const String & src_path, const String & dst_path, bool send_metadata);

    void setLastModified(const String & path, const Poco::Timestamp & timestamp) override;

@ -122,6 +141,8 @@ public:

    void shutdown() override;

+    void startup() override;
+
    /// Return some uniq string for file
    /// Required for distinguish different copies of the same part on S3
    String getUniqueId(const String & path) const override;
@ -130,15 +151,11 @@ public:
    /// Required for S3 to ensure that replica has access to data wroten by other node
    bool checkUniqueId(const String & id) const override;

-    /// Actions performed after disk creation.
-    void startup();
-
-    /// Restore S3 metadata files on file system.
-    void restore();
-
    /// Dumps current revision counter into file 'revision.txt' at given path.
    void onFreeze(const String & path) override;

+    void applyNewSettings(const Poco::Util::AbstractConfiguration & config, ContextConstPtr context) override;
+
 private:
    bool tryReserve(UInt64 bytes);

@ -146,6 +163,7 @@ private:
    void removeMetaRecursive(const String & path, AwsS3KeyKeeper & keys);
    void removeAws(const AwsS3KeyKeeper & keys);

+    Metadata readOrCreateMetaForWriting(const String & path, WriteMode mode);
    Metadata readMeta(const String & path) const;
    Metadata createMeta(const String & path) const;

@ -153,7 +171,7 @@ private:
    /// Converts revision to binary string with leading zeroes (64 bit).
    static String revisionToString(UInt64 revision);

-    bool checkObjectExists(const String & source_bucket, const String & prefix);
+    bool checkObjectExists(const String & source_bucket, const String & prefix) const;
    void findLastRevision();

    int readSchemaVersion(const String & source_bucket, const String & source_path);
@ -163,10 +181,12 @@ private:
    void migrateToRestorableSchemaRecursive(const String & path, Futures & results);
    void migrateToRestorableSchema();

-    Aws::S3::Model::HeadObjectResult headObject(const String & source_bucket, const String & key);
-    void listObjects(const String & source_bucket, const String & source_path, std::function<bool(const Aws::S3::Model::ListObjectsV2Result &)> callback);
-    void copyObject(const String & src_bucket, const String & src_key, const String & dst_bucket, const String & dst_key);
+    Aws::S3::Model::HeadObjectResult headObject(const String & source_bucket, const String & key) const;
+    void listObjects(const String & source_bucket, const String & source_path, std::function<bool(const Aws::S3::Model::ListObjectsV2Result &)> callback) const;
+    void copyObject(const String & src_bucket, const String & src_key, const String & dst_bucket, const String & dst_key) const;

+    /// Restore S3 metadata files on file system.
+    void restore();
    void readRestoreInformation(RestoreInformation & restore_information);
    void restoreFiles(const RestoreInformation & restore_information);
    void processRestoreFiles(const String & source_bucket, const String & source_path, std::vector<String> keys);
@ -181,29 +201,24 @@ private:
    static String pathToDetached(const String & source_path);

    const String name;
-    std::shared_ptr<Aws::S3::S3Client> client;
-    std::shared_ptr<S3::ProxyConfiguration> proxy_configuration;
    const String bucket;
    const String s3_root_path;
-    String metadata_path;
-    UInt64 s3_max_single_read_retries;
-    size_t min_upload_part_size;
-    size_t max_single_part_upload_size;
-    size_t min_bytes_for_seek;
-    bool send_metadata;
+    const String metadata_path;
+    MultiVersion<DiskS3Settings> current_settings;
+
+    /// Gets disk settings from context.
+    GetDiskSettings settings_getter;

    UInt64 reserved_bytes = 0;
    UInt64 reservation_count = 0;
    std::mutex reservation_mutex;

-    std::atomic<UInt64> revision_counter;
+    std::atomic<UInt64> revision_counter = 0;
    static constexpr UInt64 LATEST_REVISION = std::numeric_limits<UInt64>::max();
    static constexpr UInt64 UNKNOWN_REVISION = 0;

    /// File at path {metadata_path}/restore contains metadata restore information
    inline static const String RESTORE_FILE_NAME = "restore";
-    /// The number of keys listed in one request (1000 is max value)
-    int list_object_keys_size;

    /// Key has format: ../../r{revision}-{operation}
    const re2::RE2 key_regexp {".*/r(\\d+)-(\\w+).*"};
--- a/src/Disks/S3/registerDiskS3.cpp
+++ b/src/Disks/S3/registerDiskS3.cpp
@ -19,6 +19,7 @@
 #include "ProxyConfiguration.h"
 #include "ProxyListConfiguration.h"
 #include "ProxyResolverConfiguration.h"
+#include "Disks/DiskRestartProxy.h"


 namespace DB
@ -31,84 +32,132 @@ namespace ErrorCodes

 namespace
 {
-    void checkWriteAccess(IDisk & disk)
-    {
-        auto file = disk.writeFile("test_acl", DBMS_DEFAULT_BUFFER_SIZE, WriteMode::Rewrite);
-        file->write("test", 4);
-    }
+void checkWriteAccess(IDisk & disk)
+{
+    auto file = disk.writeFile("test_acl", DBMS_DEFAULT_BUFFER_SIZE, WriteMode::Rewrite);
+    file->write("test", 4);
+}

-    void checkReadAccess(const String & disk_name, IDisk & disk)
-    {
-        auto file = disk.readFile("test_acl", DBMS_DEFAULT_BUFFER_SIZE);
-        String buf(4, '0');
-        file->readStrict(buf.data(), 4);
-        if (buf != "test")
-            throw Exception("No read access to S3 bucket in disk " + disk_name, ErrorCodes::PATH_ACCESS_DENIED);
-    }
+void checkReadAccess(const String & disk_name, IDisk & disk)
+{
+    auto file = disk.readFile("test_acl", DBMS_DEFAULT_BUFFER_SIZE);
+    String buf(4, '0');
+    file->readStrict(buf.data(), 4);
+    if (buf != "test")
+        throw Exception("No read access to S3 bucket in disk " + disk_name, ErrorCodes::PATH_ACCESS_DENIED);
+}

-    void checkRemoveAccess(IDisk & disk) { disk.removeFile("test_acl"); }
+void checkRemoveAccess(IDisk & disk) { disk.removeFile("test_acl"); }

-    std::shared_ptr<S3::ProxyResolverConfiguration> getProxyResolverConfiguration(
-        const String & prefix, const Poco::Util::AbstractConfiguration & proxy_resolver_config)
-    {
-        auto endpoint = Poco::URI(proxy_resolver_config.getString(prefix + ".endpoint"));
-        auto proxy_scheme = proxy_resolver_config.getString(prefix + ".proxy_scheme");
-        if (proxy_scheme != "http" && proxy_scheme != "https")
-            throw Exception("Only HTTP/HTTPS schemas allowed in proxy resolver config: " + proxy_scheme, ErrorCodes::BAD_ARGUMENTS);
-        auto proxy_port = proxy_resolver_config.getUInt(prefix + ".proxy_port");
+std::shared_ptr<S3::ProxyResolverConfiguration> getProxyResolverConfiguration(
+    const String & prefix, const Poco::Util::AbstractConfiguration & proxy_resolver_config)
+{
+    auto endpoint = Poco::URI(proxy_resolver_config.getString(prefix + ".endpoint"));
+    auto proxy_scheme = proxy_resolver_config.getString(prefix + ".proxy_scheme");
+    if (proxy_scheme != "http" && proxy_scheme != "https")
+        throw Exception("Only HTTP/HTTPS schemas allowed in proxy resolver config: " + proxy_scheme, ErrorCodes::BAD_ARGUMENTS);
+    auto proxy_port = proxy_resolver_config.getUInt(prefix + ".proxy_port");

-        LOG_DEBUG(&Poco::Logger::get("DiskS3"), "Configured proxy resolver: {}, Scheme: {}, Port: {}",
-            endpoint.toString(), proxy_scheme, proxy_port);
+    LOG_DEBUG(&Poco::Logger::get("DiskS3"), "Configured proxy resolver: {}, Scheme: {}, Port: {}",
+        endpoint.toString(), proxy_scheme, proxy_port);

-        return std::make_shared<S3::ProxyResolverConfiguration>(endpoint, proxy_scheme, proxy_port);
-    }
+    return std::make_shared<S3::ProxyResolverConfiguration>(endpoint, proxy_scheme, proxy_port);
+}

-    std::shared_ptr<S3::ProxyListConfiguration> getProxyListConfiguration(
-        const String & prefix, const Poco::Util::AbstractConfiguration & proxy_config)
-    {
-        std::vector<String> keys;
-        proxy_config.keys(prefix, keys);
+std::shared_ptr<S3::ProxyListConfiguration> getProxyListConfiguration(
+    const String & prefix, const Poco::Util::AbstractConfiguration & proxy_config)
+{
+    std::vector<String> keys;
+    proxy_config.keys(prefix, keys);

-        std::vector<Poco::URI> proxies;
-        for (const auto & key : keys)
-            if (startsWith(key, "uri"))
-            {
-                Poco::URI proxy_uri(proxy_config.getString(prefix + "." + key));
-
-                if (proxy_uri.getScheme() != "http" && proxy_uri.getScheme() != "https")
-                    throw Exception("Only HTTP/HTTPS schemas allowed in proxy uri: " + proxy_uri.toString(), ErrorCodes::BAD_ARGUMENTS);
-                if (proxy_uri.getHost().empty())
-                    throw Exception("Empty host in proxy uri: " + proxy_uri.toString(), ErrorCodes::BAD_ARGUMENTS);
-
-                proxies.push_back(proxy_uri);
-
-                LOG_DEBUG(&Poco::Logger::get("DiskS3"), "Configured proxy: {}", proxy_uri.toString());
-            }
-
-        if (!proxies.empty())
-            return std::make_shared<S3::ProxyListConfiguration>(proxies);
-
-        return nullptr;
-    }
-
-    std::shared_ptr<S3::ProxyConfiguration> getProxyConfiguration(const String & prefix, const Poco::Util::AbstractConfiguration & config)
-    {
-        if (!config.has(prefix + ".proxy"))
-            return nullptr;
-
-        std::vector<String> config_keys;
-        config.keys(prefix + ".proxy", config_keys);
-
-        if (auto resolver_configs = std::count(config_keys.begin(), config_keys.end(), "resolver"))
+    std::vector<Poco::URI> proxies;
+    for (const auto & key : keys)
+        if (startsWith(key, "uri"))
        {
-            if (resolver_configs > 1)
-                throw Exception("Multiple proxy resolver configurations aren't allowed", ErrorCodes::BAD_ARGUMENTS);
+            Poco::URI proxy_uri(proxy_config.getString(prefix + "." + key));

-            return getProxyResolverConfiguration(prefix + ".proxy.resolver", config);
+            if (proxy_uri.getScheme() != "http" && proxy_uri.getScheme() != "https")
+                throw Exception("Only HTTP/HTTPS schemas allowed in proxy uri: " + proxy_uri.toString(), ErrorCodes::BAD_ARGUMENTS);
+            if (proxy_uri.getHost().empty())
+                throw Exception("Empty host in proxy uri: " + proxy_uri.toString(), ErrorCodes::BAD_ARGUMENTS);
+
+            proxies.push_back(proxy_uri);
+
+            LOG_DEBUG(&Poco::Logger::get("DiskS3"), "Configured proxy: {}", proxy_uri.toString());
        }

-        return getProxyListConfiguration(prefix + ".proxy", config);
+    if (!proxies.empty())
+        return std::make_shared<S3::ProxyListConfiguration>(proxies);
+
+    return nullptr;
+}
+
+std::shared_ptr<S3::ProxyConfiguration> getProxyConfiguration(const String & prefix, const Poco::Util::AbstractConfiguration & config)
+{
+    if (!config.has(prefix + ".proxy"))
+        return nullptr;
+
+    std::vector<String> config_keys;
+    config.keys(prefix + ".proxy", config_keys);
+
+    if (auto resolver_configs = std::count(config_keys.begin(), config_keys.end(), "resolver"))
+    {
+        if (resolver_configs > 1)
+            throw Exception("Multiple proxy resolver configurations aren't allowed", ErrorCodes::BAD_ARGUMENTS);
+
+        return getProxyResolverConfiguration(prefix + ".proxy.resolver", config);
    }
+
+    return getProxyListConfiguration(prefix + ".proxy", config);
+}
+
+std::shared_ptr<Aws::S3::S3Client>
+getClient(const Poco::Util::AbstractConfiguration & config, const String & config_prefix, ContextConstPtr context)
+{
+    S3::PocoHTTPClientConfiguration client_configuration = S3::ClientFactory::instance().createClientConfiguration(
+        context->getRemoteHostFilter(), context->getGlobalContext()->getSettingsRef().s3_max_redirects);
+
+    S3::URI uri(Poco::URI(config.getString(config_prefix + ".endpoint")));
+    if (uri.key.back() != '/')
+        throw Exception("S3 path must ends with '/', but '" + uri.key + "' doesn't.", ErrorCodes::BAD_ARGUMENTS);
+
+    client_configuration.connectTimeoutMs = config.getUInt(config_prefix + ".connect_timeout_ms", 10000);
+    client_configuration.requestTimeoutMs = config.getUInt(config_prefix + ".request_timeout_ms", 5000);
+    client_configuration.maxConnections = config.getUInt(config_prefix + ".max_connections", 100);
+    client_configuration.endpointOverride = uri.endpoint;
+
+    auto proxy_config = getProxyConfiguration(config_prefix, config);
+    if (proxy_config)
+        client_configuration.perRequestConfiguration
+            = [proxy_config](const auto & request) { return proxy_config->getConfiguration(request); };
+
+    client_configuration.retryStrategy
+        = std::make_shared<Aws::Client::DefaultRetryStrategy>(config.getUInt(config_prefix + ".retry_attempts", 10));
+
+    return S3::ClientFactory::instance().create(
+        client_configuration,
+        uri.is_virtual_hosted_style,
+        config.getString(config_prefix + ".access_key_id", ""),
+        config.getString(config_prefix + ".secret_access_key", ""),
+        config.getString(config_prefix + ".server_side_encryption_customer_key_base64", ""),
+        {},
+        config.getBool(config_prefix + ".use_environment_credentials", config.getBool("s3.use_environment_credentials", false)),
+        config.getBool(config_prefix + ".use_insecure_imds_request", config.getBool("s3.use_insecure_imds_request", false)));
+}
+
+std::unique_ptr<DiskS3Settings> getSettings(const Poco::Util::AbstractConfiguration & config, const String & config_prefix, ContextConstPtr context)
+{
+    return std::make_unique<DiskS3Settings>(
+        getClient(config, config_prefix, context),
+        config.getUInt64(config_prefix + ".s3_max_single_read_retries", context->getSettingsRef().s3_max_single_read_retries),
+        config.getUInt64(config_prefix + ".s3_min_upload_part_size", context->getSettingsRef().s3_min_upload_part_size),
+        config.getUInt64(config_prefix + ".s3_max_single_part_upload_size", context->getSettingsRef().s3_max_single_part_upload_size),
+        config.getUInt64(config_prefix + ".min_bytes_for_seek", 1024 * 1024),
+        config.getBool(config_prefix + ".send_metadata", false),
+        config.getInt(config_prefix + ".thread_pool_size", 16),
+        config.getInt(config_prefix + ".list_object_keys_size", 1000));
+}
+
 }


@ -118,56 +167,20 @@ void registerDiskS3(DiskFactory & factory)
                      const Poco::Util::AbstractConfiguration & config,
                      const String & config_prefix,
                      ContextConstPtr context) -> DiskPtr {
-        Poco::File disk{context->getPath() + "disks/" + name};
-        disk.createDirectories();
-
-        S3::PocoHTTPClientConfiguration client_configuration = S3::ClientFactory::instance().createClientConfiguration(
-            context->getRemoteHostFilter(),
-            context->getGlobalContext()->getSettingsRef().s3_max_redirects);
-
        S3::URI uri(Poco::URI(config.getString(config_prefix + ".endpoint")));
        if (uri.key.back() != '/')
            throw Exception("S3 path must ends with '/', but '" + uri.key + "' doesn't.", ErrorCodes::BAD_ARGUMENTS);

-        client_configuration.connectTimeoutMs = config.getUInt(config_prefix + ".connect_timeout_ms", 10000);
-        client_configuration.requestTimeoutMs = config.getUInt(config_prefix + ".request_timeout_ms", 5000);
-        client_configuration.maxConnections = config.getUInt(config_prefix + ".max_connections", 100);
-        client_configuration.endpointOverride = uri.endpoint;
-
-        auto proxy_config = getProxyConfiguration(config_prefix, config);
-        if (proxy_config)
-            client_configuration.perRequestConfiguration = [proxy_config](const auto & request) { return proxy_config->getConfiguration(request); };
-
-        client_configuration.retryStrategy = std::make_shared<Aws::Client::DefaultRetryStrategy>(
-            config.getUInt(config_prefix + ".retry_attempts", 10));
-
-        auto client = S3::ClientFactory::instance().create(
-            client_configuration,
-            uri.is_virtual_hosted_style,
-            config.getString(config_prefix + ".access_key_id", ""),
-            config.getString(config_prefix + ".secret_access_key", ""),
-            config.getString(config_prefix + ".server_side_encryption_customer_key_base64", ""),
-            {},
-            config.getBool(config_prefix + ".use_environment_credentials", config.getBool("s3.use_environment_credentials", false)),
-            config.getBool(config_prefix + ".use_insecure_imds_request", config.getBool("s3.use_insecure_imds_request", false))
-        );
-
        String metadata_path = config.getString(config_prefix + ".metadata_path", context->getPath() + "disks/" + name + "/");
+        Poco::File (metadata_path).createDirectories();

-        auto s3disk = std::make_shared<DiskS3>(
+        std::shared_ptr<IDisk> s3disk = std::make_shared<DiskS3>(
            name,
-            client,
-            proxy_config,
            uri.bucket,
            uri.key,
            metadata_path,
-            context->getSettingsRef().s3_max_single_read_retries,
-            context->getSettingsRef().s3_min_upload_part_size,
-            context->getSettingsRef().s3_max_single_part_upload_size,
-            config.getUInt64(config_prefix + ".min_bytes_for_seek", 1024 * 1024),
-            config.getBool(config_prefix + ".send_metadata", false),
-            config.getInt(config_prefix + ".thread_pool_size", 16),
-            config.getInt(config_prefix + ".list_object_keys_size", 1000));
+            getSettings(config, config_prefix, context),
+            getSettings);

        /// This code is used only to check access to the corresponding disk.
        if (!config.getBool(config_prefix + ".skip_access_check", false))
@ -177,7 +190,6 @@ void registerDiskS3(DiskFactory & factory)
            checkRemoveAccess(*s3disk);
        }

-        s3disk->restore();
        s3disk->startup();

        bool cache_enabled = config.getBool(config_prefix + ".cache_enabled", true);
@ -197,10 +209,10 @@ void registerDiskS3(DiskFactory & factory)
                       || path.ends_with("txt") || path.ends_with("dat");
            };

-            return std::make_shared<DiskCacheWrapper>(s3disk, cache_disk, cache_file_predicate);
+            s3disk = std::make_shared<DiskCacheWrapper>(s3disk, cache_disk, cache_file_predicate);
        }

-        return s3disk;
+        return std::make_shared<DiskRestartProxy>(s3disk);
    };
    factory.registerDiskType("s3", creator);
 }
--- a/src/IO/ReadBufferFromFileDecorator.cpp
+++ b/src/IO/ReadBufferFromFileDecorator.cpp
@ -0,0 +1,46 @@
+#include <IO/ReadBufferFromFileDecorator.h>
+
+
+namespace DB
+{
+
+ReadBufferFromFileDecorator::ReadBufferFromFileDecorator(std::unique_ptr<ReadBufferFromFileBase> impl_)
+    : impl(std::move(impl_))
+{
+    swap(*impl);
+}
+
+
+std::string ReadBufferFromFileDecorator::getFileName() const
+{
+    return impl->getFileName();
+}
+
+
+off_t ReadBufferFromFileDecorator::getPosition()
+{
+    swap(*impl);
+    auto position = impl->getPosition();
+    swap(*impl);
+    return position;
+}
+
+
+off_t ReadBufferFromFileDecorator::seek(off_t off, int whence)
+{
+    swap(*impl);
+    auto result = impl->seek(off, whence);
+    swap(*impl);
+    return result;
+}
+
+
+bool ReadBufferFromFileDecorator::nextImpl()
+{
+    swap(*impl);
+    auto result = impl->next();
+    swap(*impl);
+    return result;
+}
+
+}
--- a/src/IO/ReadBufferFromFileDecorator.h
+++ b/src/IO/ReadBufferFromFileDecorator.h
@ -0,0 +1,27 @@
+#pragma once
+
+#include <IO/ReadBufferFromFileBase.h>
+
+
+namespace DB
+{
+
+/// Delegates all reads to underlying buffer. Doesn't have own memory.
+class ReadBufferFromFileDecorator : public ReadBufferFromFileBase
+{
+public:
+    explicit ReadBufferFromFileDecorator(std::unique_ptr<ReadBufferFromFileBase> impl_);
+
+    std::string getFileName() const override;
+
+    off_t getPosition() override;
+
+    off_t seek(off_t off, int whence) override;
+
+    bool nextImpl() override;
+
+protected:
+    std::unique_ptr<ReadBufferFromFileBase> impl;
+};
+
+}
--- a/src/IO/SeekAvoidingReadBuffer.cpp
+++ b/src/IO/SeekAvoidingReadBuffer.cpp
@ -4,28 +4,10 @@
 namespace DB
 {

-SeekAvoidingReadBuffer::SeekAvoidingReadBuffer(std::unique_ptr<ReadBufferFromFileBase> nested_, UInt64 min_bytes_for_seek_)
-    : nested(std::move(nested_))
+SeekAvoidingReadBuffer::SeekAvoidingReadBuffer(std::unique_ptr<ReadBufferFromFileBase> impl_, UInt64 min_bytes_for_seek_)
+    : ReadBufferFromFileDecorator(std::move(impl_))
    , min_bytes_for_seek(min_bytes_for_seek_)
-{
-    swap(*nested);
-}
-
-
-std::string SeekAvoidingReadBuffer::getFileName() const
-{
-    return nested->getFileName();
-}
-
-
-off_t SeekAvoidingReadBuffer::getPosition()
-{
-    swap(*nested);
-    off_t position = nested->getPosition();
-    swap(*nested);
-    return position;
-}
-
+{ }

 off_t SeekAvoidingReadBuffer::seek(off_t off, int whence)
 {
@ -39,28 +21,13 @@ off_t SeekAvoidingReadBuffer::seek(off_t off, int whence)

    if (whence == SEEK_SET && off >= position && off < position + static_cast<off_t>(min_bytes_for_seek))
    {
-        swap(*nested);
-        nested->ignore(off - position);
-        swap(*nested);
-        position = off;
-    }
-    else
-    {
-        swap(*nested);
-        position = nested->seek(off, whence);
-        swap(*nested);
+        swap(*impl);
+        impl->ignore(off - position);
+        swap(*impl);
+        return off;
    }

-    return position;
-}
-
-
-bool SeekAvoidingReadBuffer::nextImpl()
-{
-    swap(*nested);
-    bool nested_result = nested->next();
-    swap(*nested);
-    return nested_result;
+    return ReadBufferFromFileDecorator::seek(off, whence);
 }

 }
--- a/src/IO/SeekAvoidingReadBuffer.h
+++ b/src/IO/SeekAvoidingReadBuffer.h
@ -1,6 +1,6 @@
 #pragma once

-#include <IO/ReadBufferFromFileBase.h>
+#include <IO/ReadBufferFromFileDecorator.h>


 namespace DB
@ -10,22 +10,15 @@ namespace DB
 /// It is useful in network and spinning disk storage media when seek is relatively expensive
 /// operation.
 /// See also: `merge_tree_min_rows_for_seek`.
-class SeekAvoidingReadBuffer : public ReadBufferFromFileBase
+class SeekAvoidingReadBuffer : public ReadBufferFromFileDecorator
 {
-    std::unique_ptr<ReadBufferFromFileBase> nested;
-
-    UInt64 min_bytes_for_seek; /// Minimum positive seek offset which shall be executed using seek operation.
-
 public:
-    SeekAvoidingReadBuffer(std::unique_ptr<ReadBufferFromFileBase> nested_, UInt64 min_bytes_for_seek_);
-
-    std::string getFileName() const override;
-
-    off_t getPosition() override;
+    SeekAvoidingReadBuffer(std::unique_ptr<ReadBufferFromFileBase> impl_, UInt64 min_bytes_for_seek_);

    off_t seek(off_t off, int whence) override;

-    bool nextImpl() override;
+private:
+    UInt64 min_bytes_for_seek; /// Minimum positive seek offset which shall be executed using seek operation.
 };

 }
--- a/src/IO/WriteBufferFromFileDecorator.cpp
+++ b/src/IO/WriteBufferFromFileDecorator.cpp
@ -0,0 +1,56 @@
+#include "WriteBufferFromFileDecorator.h"
+
+#include <IO/WriteBuffer.h>
+
+namespace DB
+{
+
+WriteBufferFromFileDecorator::WriteBufferFromFileDecorator(std::unique_ptr<WriteBuffer> impl_)
+    : WriteBufferFromFileBase(0, nullptr, 0), impl(std::move(impl_))
+{
+    swap(*impl);
+}
+
+void WriteBufferFromFileDecorator::finalize()
+{
+    if (finalized)
+        return;
+
+    next();
+    impl->finalize();
+
+    finalized = true;
+}
+
+WriteBufferFromFileDecorator::~WriteBufferFromFileDecorator()
+{
+    try
+    {
+        WriteBufferFromFileDecorator::finalize();
+    }
+    catch (...)
+    {
+        tryLogCurrentException(__PRETTY_FUNCTION__);
+    }
+}
+
+void WriteBufferFromFileDecorator::sync()
+{
+    impl->sync();
+}
+
+std::string WriteBufferFromFileDecorator::getFileName() const
+{
+    if (WriteBufferFromFileBase * buffer = dynamic_cast<WriteBufferFromFileBase*>(impl.get()))
+        return buffer->getFileName();
+    return std::string();
+}
+
+void WriteBufferFromFileDecorator::nextImpl()
+{
+    swap(*impl);
+    impl->next();
+    swap(*impl);
+}
+
+}
--- a/src/IO/WriteBufferFromFileDecorator.h
+++ b/src/IO/WriteBufferFromFileDecorator.h
@ -0,0 +1,30 @@
+#pragma once
+
+#include <IO/WriteBufferFromFileBase.h>
+
+namespace DB
+{
+
+/// Delegates all writes to underlying buffer. Doesn't have own memory.
+class WriteBufferFromFileDecorator : public WriteBufferFromFileBase
+{
+public:
+    explicit WriteBufferFromFileDecorator(std::unique_ptr<WriteBuffer> impl_);
+
+    ~WriteBufferFromFileDecorator() override;
+
+    void finalize() override;
+
+    void sync() override;
+
+    std::string getFileName() const override;
+
+protected:
+    std::unique_ptr<WriteBuffer> impl;
+    bool finalized = false;
+
+private:
+    void nextImpl() override;
+};
+
+}
--- a/src/Interpreters/InterpreterSystemQuery.cpp
+++ b/src/Interpreters/InterpreterSystemQuery.cpp
@ -29,6 +29,7 @@
 #include <Access/ContextAccess.h>
 #include <Access/AllowedClientHosts.h>
 #include <Databases/IDatabase.h>
+#include <Disks/DiskRestartProxy.h>
 #include <Storages/StorageDistributed.h>
 #include <Storages/StorageReplicatedMergeTree.h>
 #include <Storages/StorageFactory.h>
@ -394,6 +395,9 @@ BlockIO InterpreterSystemQuery::execute()
                throw Exception("There is no " + query.database + "." + query.table + " replicated table",
                                ErrorCodes::BAD_ARGUMENTS);
            break;
+        case Type::RESTART_DISK:
+            restartDisk(query.disk);
+            break;
        case Type::FLUSH_LOGS:
        {
            getContext()->checkAccess(AccessType::SYSTEM_FLUSH_LOGS);
@ -637,6 +641,18 @@ void InterpreterSystemQuery::flushDistributed(ASTSystemQuery &)
        throw Exception("Table " + table_id.getNameForLogs() + " is not distributed", ErrorCodes::BAD_ARGUMENTS);
 }

+void InterpreterSystemQuery::restartDisk(String & name)
+{
+    getContext()->checkAccess(AccessType::SYSTEM_RESTART_DISK);
+
+    auto disk = getContext()->getDisk(name);
+
+    if (DiskRestartProxy * restart_proxy = dynamic_cast<DiskRestartProxy*>(disk.get()))
+        restart_proxy->restart();
+    else
+        throw Exception("Disk " + name + " doesn't have possibility to restart", ErrorCodes::BAD_ARGUMENTS);
+}
+

 AccessRightsElements InterpreterSystemQuery::getRequiredAccessForDDLOnCluster() const
 {
@ -779,6 +795,11 @@ AccessRightsElements InterpreterSystemQuery::getRequiredAccessForDDLOnCluster()
            required_access.emplace_back(AccessType::SYSTEM_FLUSH_LOGS);
            break;
        }
+        case Type::RESTART_DISK:
+        {
+            required_access.emplace_back(AccessType::SYSTEM_RESTART_DISK);
+            break;
+        }
        case Type::STOP_LISTEN_QUERIES: break;
        case Type::START_LISTEN_QUERIES: break;
        case Type::UNKNOWN: break;
--- a/src/Interpreters/InterpreterSystemQuery.h
+++ b/src/Interpreters/InterpreterSystemQuery.h
@ -52,6 +52,7 @@ private:
    void dropReplica(ASTSystemQuery & query);
    bool dropReplicaImpl(ASTSystemQuery & query, const StoragePtr & table);
    void flushDistributed(ASTSystemQuery & query);
+    void restartDisk(String & name);

    AccessRightsElements getRequiredAccessForDDLOnCluster() const;
    void startStopAction(StorageActionBlockType action_type, bool start);
--- a/src/Parsers/ASTSystemQuery.cpp
+++ b/src/Parsers/ASTSystemQuery.cpp
@ -94,6 +94,8 @@ const char * ASTSystemQuery::typeToString(Type type)
            return "START DISTRIBUTED SENDS";
        case Type::FLUSH_LOGS:
            return "FLUSH LOGS";
+        case Type::RESTART_DISK:
+            return "RESTART DISK";
        default:
            throw Exception("Unknown SYSTEM query command", ErrorCodes::LOGICAL_ERROR);
    }
--- a/src/Parsers/ASTSystemQuery.h
+++ b/src/Parsers/ASTSystemQuery.h
@ -41,6 +41,7 @@ public:
        RELOAD_EMBEDDED_DICTIONARIES,
        RELOAD_CONFIG,
        RELOAD_SYMBOLS,
+        RESTART_DISK,
        STOP_MERGES,
        START_MERGES,
        STOP_TTL_MERGES,
@ -73,6 +74,7 @@ public:
    bool is_drop_whole_replica{};
    String storage_policy;
    String volume;
+    String disk;
    UInt64 seconds{};

    String getID(char) const override { return "SYSTEM query"; }
--- a/src/Parsers/ParserSystemQuery.cpp
+++ b/src/Parsers/ParserSystemQuery.cpp
@ -134,6 +134,17 @@ bool ParserSystemQuery::parseImpl(IParser::Pos & pos, ASTPtr & node, Expected &
                return false;
            break;

+        case Type::RESTART_DISK:
+        {
+            ASTPtr ast;
+            if (ParserIdentifier{}.parse(pos, ast, expected))
+                res->disk = ast->as<ASTIdentifier &>().name();
+            else
+                return false;
+
+            break;
+        }
+
        case Type::STOP_DISTRIBUTED_SENDS:
        case Type::START_DISTRIBUTED_SENDS:
        case Type::FLUSH_DISTRIBUTED:
--- a/tests/integration/test_merge_tree_s3/configs/config.d/storage_conf.xml
+++ b/tests/integration/test_merge_tree_s3/configs/config.d/storage_conf.xml
@ -6,6 +6,7 @@
                <endpoint>http://minio1:9001/root/data/</endpoint>
                <access_key_id>minio</access_key_id>
                <secret_access_key>minio123</secret_access_key>
+                <s3_max_single_part_upload_size>33554432</s3_max_single_part_upload_size>
            </s3>
            <hdd>
                <type>local</type>
--- a/tests/integration/test_merge_tree_s3/configs/config.d/users.xml
+++ b/tests/integration/test_merge_tree_s3/configs/config.d/users.xml
@ -1,5 +0,0 @@
-<yandex>
-    <profiles>
-        <default/>
-    </profiles>
-</yandex>
--- a/tests/integration/test_merge_tree_s3/test.py
+++ b/tests/integration/test_merge_tree_s3/test.py
@ -2,6 +2,8 @@ import logging
 import random
 import string
 import time
+import threading
+import os

 import pytest
 from helpers.cluster import ClickHouseCluster
@ -10,13 +12,47 @@ logging.getLogger().setLevel(logging.INFO)
 logging.getLogger().addHandler(logging.StreamHandler())


+# By default the exceptions that was throwed in threads will be ignored
+# (they will not mark the test as failed, only printed to stderr).
+#
+# Wrap thrading.Thread and re-throw exception on join()
+class SafeThread(threading.Thread):
+    def __init__(self, target):
+        super().__init__()
+        self.target = target
+        self.exception = None
+    def run(self):
+        try:
+            self.target()
+        except Exception as e: # pylint: disable=broad-except
+            self.exception = e
+    def join(self, timeout=None):
+        super().join(timeout)
+        if self.exception:
+            raise self.exception
+
+
+SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
+CONFIG_PATH = os.path.join(SCRIPT_DIR, './_instances/node/configs/config.d/storage_conf.xml')
+
+
+def replace_config(old, new):
+    config = open(CONFIG_PATH, 'r')
+    config_lines = config.readlines()
+    config.close()
+    config_lines = [line.replace(old, new) for line in config_lines]
+    config = open(CONFIG_PATH, 'w')
+    config.writelines(config_lines)
+    config.close()
+
+
@pytest.fixture(scope="module")
 def cluster():
    try:
        cluster = ClickHouseCluster(__file__)
        cluster.add_instance("node", main_configs=["configs/config.d/storage_conf.xml",
                                                   "configs/config.d/bg_processing_pool_conf.xml",
-                                                   "configs/config.d/log_conf.xml"], user_configs=[], with_minio=True)
+                                                   "configs/config.d/log_conf.xml"], with_minio=True)
        logging.info("Starting cluster...")
        cluster.start()
        logging.info("Cluster started")
@ -365,3 +401,63 @@ def test_freeze_unfreeze(cluster):
    # Data should be removed from S3.
    assert len(
        list(minio.list_objects(cluster.minio_bucket, 'data/'))) == FILES_OVERHEAD
+
+
+def test_s3_disk_apply_new_settings(cluster):
+    create_table(cluster, "s3_test")
+    node = cluster.instances["node"]
+
+    def get_s3_requests():
+        node.query("SYSTEM FLUSH LOGS")
+        return int(node.query("SELECT value FROM system.events WHERE event='S3WriteRequestsCount'"))
+
+    s3_requests_before = get_s3_requests()
+    node.query("INSERT INTO s3_test VALUES {}".format(generate_values('2020-01-03', 4096)))
+    s3_requests_to_write_partition = get_s3_requests() - s3_requests_before
+
+    # Force multi-part upload mode.
+    replace_config("<s3_max_single_part_upload_size>33554432</s3_max_single_part_upload_size>",
+                   "<s3_max_single_part_upload_size>0</s3_max_single_part_upload_size>")
+
+    node.query("SYSTEM RELOAD CONFIG")
+
+    s3_requests_before = get_s3_requests()
+    node.query("INSERT INTO s3_test VALUES {}".format(generate_values('2020-01-04', 4096, -1)))
+
+    # There should be 3 times more S3 requests because multi-part upload mode uses 3 requests to upload object.
+    assert get_s3_requests() - s3_requests_before == s3_requests_to_write_partition * 3
+
+
+def test_s3_disk_restart_during_load(cluster):
+    create_table(cluster, "s3_test")
+
+    node = cluster.instances["node"]
+
+    node.query("INSERT INTO s3_test VALUES {}".format(generate_values('2020-01-04', 1024 * 1024)))
+    node.query("INSERT INTO s3_test VALUES {}".format(generate_values('2020-01-05', 1024 * 1024, -1)))
+
+    def read():
+        for ii in range(0, 20):
+            logging.info("Executing %d query", ii)
+            assert node.query("SELECT sum(id) FROM s3_test FORMAT Values") == "(0)"
+            logging.info("Query %d executed", ii)
+            time.sleep(0.2)
+
+    def restart_disk():
+        for iii in range(0, 5):
+            logging.info("Restarting disk, attempt %d", iii)
+            node.query("SYSTEM RESTART DISK s3")
+            logging.info("Disk restarted, attempt %d", iii)
+            time.sleep(0.5)
+
+    threads = []
+    for i in range(0, 4):
+        threads.append(SafeThread(target=read))
+
+    threads.append(SafeThread(target=restart_disk))
+
+    for thread in threads:
+        thread.start()
+
+    for thread in threads:
+        thread.join()
--- a/tests/integration/test_merge_tree_s3_restore/test.py
+++ b/tests/integration/test_merge_tree_s3_restore/test.py
@ -66,11 +66,11 @@ def generate_values(date_str, count, sign=1):
    return ",".join(["('{}',{},'{}',{})".format(x, y, z, 0) for x, y, z in data])


-def create_table(node, table_name, replicated=False):
+def create_table(node, table_name, attach=False, replicated=False):
    node.query("CREATE DATABASE IF NOT EXISTS s3 ENGINE = Ordinary")

    create_table_statement = """
-        CREATE TABLE s3.{table_name} {on_cluster} (
+        {create} TABLE s3.{table_name} {on_cluster} (
            dt Date,
            id Int64,
            data String,
@ -83,7 +83,8 @@ def create_table(node, table_name, replicated=False):
            storage_policy='s3',
            old_parts_lifetime=600,
            index_granularity=512
-        """.format(table_name=table_name,
+        """.format(create="ATTACH" if attach else "CREATE",
+                   table_name=table_name,
                   on_cluster="ON CLUSTER '{}'".format(node.name) if replicated else "",
                   engine="ReplicatedMergeTree('/clickhouse/tables/{cluster}/test', '{replica}')" if replicated else "MergeTree()")

@ -107,6 +108,7 @@ def drop_shadow_information(node):


 def create_restore_file(node, revision=None, bucket=None, path=None, detached=None):
+    node.exec_in_container(['bash', '-c', 'mkdir -p /var/lib/clickhouse/disks/s3/'], user='root')
    node.exec_in_container(['bash', '-c', 'touch /var/lib/clickhouse/disks/s3/restore'], user='root')

    add_restore_option = 'echo -en "{}={}\n" >> /var/lib/clickhouse/disks/s3/restore'
@ -150,17 +152,18 @@ def drop_table(cluster):
 def test_full_restore(cluster, replicated):
    node = cluster.instances["node"]

-    create_table(node, "test", replicated)
+    create_table(node, "test", attach=False, replicated=replicated)

    node.query("INSERT INTO s3.test VALUES {}".format(generate_values('2020-01-03', 4096)))
    node.query("INSERT INTO s3.test VALUES {}".format(generate_values('2020-01-04', 4096, -1)))
    node.query("INSERT INTO s3.test VALUES {}".format(generate_values('2020-01-05', 4096)))
    node.query("INSERT INTO s3.test VALUES {}".format(generate_values('2020-01-05', 4096, -1)))

-    node.stop_clickhouse()
+    node.query("DETACH TABLE s3.test")
    drop_s3_metadata(node)
    create_restore_file(node)
-    node.start_clickhouse()
+    node.query("SYSTEM RESTART DISK s3")
+    node.query("ATTACH TABLE s3.test")

    assert node.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 4)
    assert node.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)
@ -184,22 +187,18 @@ def test_restore_another_bucket_path(cluster):

    node_another_bucket = cluster.instances["node_another_bucket"]

-    create_table(node_another_bucket, "test")
-
-    node_another_bucket.stop_clickhouse()
    create_restore_file(node_another_bucket, bucket="root")
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    create_table(node_another_bucket, "test", attach=True)

    assert node_another_bucket.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 4)
    assert node_another_bucket.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)

    node_another_bucket_path = cluster.instances["node_another_bucket_path"]

-    create_table(node_another_bucket_path, "test")
-
-    node_another_bucket_path.stop_clickhouse()
    create_restore_file(node_another_bucket_path, bucket="root2", path="data")
-    node_another_bucket_path.start_clickhouse()
+    node_another_bucket_path.query("SYSTEM RESTART DISK s3")
+    create_table(node_another_bucket_path, "test", attach=True)

    assert node_another_bucket_path.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 4)
    assert node_another_bucket_path.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)
@ -234,36 +233,30 @@ def test_restore_different_revisions(cluster):

    node_another_bucket = cluster.instances["node_another_bucket"]

-    create_table(node_another_bucket, "test")
-
    # Restore to revision 1 (2 parts).
-    node_another_bucket.stop_clickhouse()
-    drop_s3_metadata(node_another_bucket)
-    purge_s3(cluster, cluster.minio_bucket_2)
    create_restore_file(node_another_bucket, revision=revision1, bucket="root")
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    create_table(node_another_bucket, "test", attach=True)

    assert node_another_bucket.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 2)
    assert node_another_bucket.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)
    assert node_another_bucket.query("SELECT count(*) from system.parts where table = 'test'") == '2\n'

    # Restore to revision 2 (4 parts).
-    node_another_bucket.stop_clickhouse()
-    drop_s3_metadata(node_another_bucket)
-    purge_s3(cluster, cluster.minio_bucket_2)
+    node_another_bucket.query("DETACH TABLE s3.test")
    create_restore_file(node_another_bucket, revision=revision2, bucket="root")
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    node_another_bucket.query("ATTACH TABLE s3.test")

    assert node_another_bucket.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 4)
    assert node_another_bucket.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)
    assert node_another_bucket.query("SELECT count(*) from system.parts where table = 'test'") == '4\n'

    # Restore to revision 3 (4 parts + 1 merged).
-    node_another_bucket.stop_clickhouse()
-    drop_s3_metadata(node_another_bucket)
-    purge_s3(cluster, cluster.minio_bucket_2)
+    node_another_bucket.query("DETACH TABLE s3.test")
    create_restore_file(node_another_bucket, revision=revision3, bucket="root")
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    node_another_bucket.query("ATTACH TABLE s3.test")

    assert node_another_bucket.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 4)
    assert node_another_bucket.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)
@ -288,25 +281,20 @@ def test_restore_mutations(cluster):

    node_another_bucket = cluster.instances["node_another_bucket"]

-    create_table(node_another_bucket, "test")
-
    # Restore to revision before mutation.
-    node_another_bucket.stop_clickhouse()
-    drop_s3_metadata(node_another_bucket)
-    purge_s3(cluster, cluster.minio_bucket_2)
    create_restore_file(node_another_bucket, revision=revision_before_mutation, bucket="root")
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    create_table(node_another_bucket, "test", attach=True)

    assert node_another_bucket.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 2)
    assert node_another_bucket.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)
    assert node_another_bucket.query("SELECT sum(counter) FROM s3.test FORMAT Values") == "({})".format(0)

    # Restore to revision after mutation.
-    node_another_bucket.stop_clickhouse()
-    drop_s3_metadata(node_another_bucket)
-    purge_s3(cluster, cluster.minio_bucket_2)
+    node_another_bucket.query("DETACH TABLE s3.test")
    create_restore_file(node_another_bucket, revision=revision_after_mutation, bucket="root")
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    node_another_bucket.query("ATTACH TABLE s3.test")

    assert node_another_bucket.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 2)
    assert node_another_bucket.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)
@ -315,12 +303,11 @@ def test_restore_mutations(cluster):

    # Restore to revision in the middle of mutation.
    # Unfinished mutation should be completed after table startup.
-    node_another_bucket.stop_clickhouse()
-    drop_s3_metadata(node_another_bucket)
-    purge_s3(cluster, cluster.minio_bucket_2)
+    node_another_bucket.query("DETACH TABLE s3.test")
    revision = (revision_before_mutation + revision_after_mutation) // 2
    create_restore_file(node_another_bucket, revision=revision, bucket="root")
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    node_another_bucket.query("ATTACH TABLE s3.test")

    # Wait for unfinished mutation completion.
    time.sleep(3)
@ -342,7 +329,6 @@ def test_migrate_to_restorable_schema(cluster):
    node.query("INSERT INTO s3.test VALUES {}".format(generate_values('2020-01-05', 4096, -1)))

    replace_config("<send_metadata>false</send_metadata>", "<send_metadata>true</send_metadata>")
-
    node.restart_clickhouse()

    node.query("INSERT INTO s3.test VALUES {}".format(generate_values('2020-01-06', 4096)))
@ -355,14 +341,10 @@ def test_migrate_to_restorable_schema(cluster):

    node_another_bucket = cluster.instances["node_another_bucket"]

-    create_table(node_another_bucket, "test")
-
    # Restore to revision before mutation.
-    node_another_bucket.stop_clickhouse()
-    drop_s3_metadata(node_another_bucket)
-    purge_s3(cluster, cluster.minio_bucket_2)
    create_restore_file(node_another_bucket, revision=revision, bucket="root", path="another_data")
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    create_table(node_another_bucket, "test", attach=True)

    assert node_another_bucket.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(4096 * 6)
    assert node_another_bucket.query("SELECT sum(id) FROM s3.test FORMAT Values") == "({})".format(0)
@ -374,7 +356,7 @@ def test_migrate_to_restorable_schema(cluster):
 def test_restore_to_detached(cluster, replicated):
    node = cluster.instances["node"]

-    create_table(node, "test", replicated)
+    create_table(node, "test", attach=False, replicated=replicated)

    node.query("INSERT INTO s3.test VALUES {}".format(generate_values('2020-01-03', 4096)))
    node.query("INSERT INTO s3.test VALUES {}".format(generate_values('2020-01-04', 4096, -1)))
@ -393,11 +375,9 @@ def test_restore_to_detached(cluster, replicated):

    node_another_bucket = cluster.instances["node_another_bucket"]

-    create_table(node_another_bucket, "test", replicated)
-
-    node_another_bucket.stop_clickhouse()
    create_restore_file(node_another_bucket, revision=revision, bucket="root", path="data", detached=True)
-    node_another_bucket.start_clickhouse()
+    node_another_bucket.query("SYSTEM RESTART DISK s3")
+    create_table(node_another_bucket, "test", replicated=replicated)

    assert node_another_bucket.query("SELECT count(*) FROM s3.test FORMAT Values") == "({})".format(0)

--- a/tests/queries/0_stateless/01271_show_privileges.reference
+++ b/tests/queries/0_stateless/01271_show_privileges.reference
@ -85,6 +85,7 @@ SYSTEM RELOAD DICTIONARY	['SYSTEM RELOAD DICTIONARIES','RELOAD DICTIONARY','RELO
 SYSTEM RELOAD MODEL	['SYSTEM RELOAD MODELS','RELOAD MODEL','RELOAD MODELS']	GLOBAL	SYSTEM RELOAD
 SYSTEM RELOAD EMBEDDED DICTIONARIES	['RELOAD EMBEDDED DICTIONARIES']	GLOBAL	SYSTEM RELOAD
 SYSTEM RELOAD	[]	\N	SYSTEM
+SYSTEM RESTART DISK	['SYSTEM RESTART DISK']	GLOBAL	SYSTEM
 SYSTEM MERGES	['SYSTEM STOP MERGES','SYSTEM START MERGES','STOP_MERGES','START MERGES']	TABLE	SYSTEM
 SYSTEM TTL MERGES	['SYSTEM STOP TTL MERGES','SYSTEM START TTL MERGES','STOP TTL MERGES','START TTL MERGES']	TABLE	SYSTEM
 SYSTEM FETCHES	['SYSTEM STOP FETCHES','SYSTEM START FETCHES','STOP FETCHES','START FETCHES']	TABLE	SYSTEM