Merge pull request #29289 from vdimir/issue-29227-rocksdb-truncate

Fix race in StorageSystemRocksDB

src/Storages/RocksDB/StorageEmbeddedRocksDB.cpp

@@ -36,6 +36,7 @@
 #include <rocksdb/convenience.h>
 
 #include <filesystem>
+#include <shared_mutex>
 
 
 namespace fs = std::filesystem;
@@ -213,9 +214,9 @@ public:
         std::vector<rocksdb::Slice> slices_keys(num_keys);
 
         const auto & sample_block = metadata_snapshot->getSampleBlock();
-        const auto & key_column = sample_block.getByName(storage.primary_key);
+        const auto & key_column = sample_block.getByName(storage.getPrimaryKey());
         auto columns = sample_block.cloneEmptyColumns();
-        size_t primary_key_pos = sample_block.getPositionByName(storage.primary_key);
+        size_t primary_key_pos = sample_block.getPositionByName(storage.getPrimaryKey());
 
         size_t rows_processed = 0;
         while (it < end && rows_processed < max_block_size)
@@ -230,8 +231,7 @@ public:
         }
 
         std::vector<String> values;
-        auto statuses = storage.rocksdb_ptr->MultiGet(rocksdb::ReadOptions(), slices_keys, &values);
+        auto statuses = storage.multiGet(slices_keys, values);
-
         for (size_t i = 0; i < statuses.size(); ++i)
         {
             if (statuses[i].ok())
@@ -285,7 +285,10 @@ StorageEmbeddedRocksDB::StorageEmbeddedRocksDB(const StorageID & table_id_,
 
 void StorageEmbeddedRocksDB::truncate(const ASTPtr &, const StorageMetadataPtr & , ContextPtr, TableExclusiveLockHolder &)
 {
+    std::unique_lock<std::shared_mutex> lock(rocksdb_ptr_mx);
     rocksdb_ptr->Close();
+    rocksdb_ptr = nullptr;
+
     fs::remove_all(rocksdb_dir);
     fs::create_directories(rocksdb_dir);
     initDb();
@@ -460,9 +463,20 @@ static StoragePtr create(const StorageFactory::Arguments & args)
 
 std::shared_ptr<rocksdb::Statistics> StorageEmbeddedRocksDB::getRocksDBStatistics() const
 {
+    std::shared_lock<std::shared_mutex> lock(rocksdb_ptr_mx);
+    if (!rocksdb_ptr)
+        return nullptr;
     return rocksdb_ptr->GetOptions().statistics;
 }
 
+std::vector<rocksdb::Status> StorageEmbeddedRocksDB::multiGet(const std::vector<rocksdb::Slice> & slices_keys, std::vector<String> & values) const
+{
+    std::shared_lock<std::shared_mutex> lock(rocksdb_ptr_mx);
+    if (!rocksdb_ptr)
+        return {};
+    return rocksdb_ptr->MultiGet(rocksdb::ReadOptions(), slices_keys, &values);
+}
+
 void registerStorageEmbeddedRocksDB(StorageFactory & factory)
 {
     StorageFactory::StorageFeatures features{

src/Storages/RocksDB/StorageEmbeddedRocksDB.h

@@ -1,8 +1,10 @@
 #pragma once
 
 #include <memory>
+#include <shared_mutex>
 #include <common/shared_ptr_helper.h>
 #include <Storages/IStorage.h>
+#include <rocksdb/status.h>
 
 
 namespace rocksdb
@@ -20,7 +22,6 @@ class Context;
 class StorageEmbeddedRocksDB final : public shared_ptr_helper<StorageEmbeddedRocksDB>, public IStorage, WithContext
 {
     friend struct shared_ptr_helper<StorageEmbeddedRocksDB>;
-    friend class EmbeddedRocksDBSource;
     friend class EmbeddedRocksDBSink;
     friend class EmbeddedRocksDBBlockInputStream;
 public:
@@ -50,6 +51,8 @@ public:
     Strings getDataPaths() const override { return {rocksdb_dir}; }
 
     std::shared_ptr<rocksdb::Statistics> getRocksDBStatistics() const;
+    std::vector<rocksdb::Status> multiGet(const std::vector<rocksdb::Slice> & slices_keys, std::vector<String> & values) const;
+    const String & getPrimaryKey() const { return primary_key; }
 
 protected:
     StorageEmbeddedRocksDB(const StorageID & table_id_,
@@ -63,6 +66,7 @@ private:
     const String primary_key;
     using RocksDBPtr = std::unique_ptr<rocksdb::DB>;
     RocksDBPtr rocksdb_ptr;
+    mutable std::shared_mutex rocksdb_ptr_mx;
     String rocksdb_dir;
 
     void initDb();

src/Storages/RocksDB/StorageSystemRocksDB.cpp

@@ -43,7 +43,8 @@ void StorageSystemRocksDB::fillData(MutableColumns & res_columns, ContextPtr con
     const auto access = context->getAccess();
     const bool check_access_for_databases = !access->isGranted(AccessType::SHOW_TABLES);
 
-    std::map<String, std::map<String, StoragePtr>> tables;
+    using RocksDBStoragePtr = std::shared_ptr<StorageEmbeddedRocksDB>;
+    std::map<String, std::map<String, RocksDBStoragePtr>> tables;
     for (const auto & db : DatabaseCatalog::instance().getDatabases())
     {
         const bool check_access_for_tables = check_access_for_databases && !access->isGranted(AccessType::SHOW_TABLES, db.first);
@@ -51,17 +52,16 @@ void StorageSystemRocksDB::fillData(MutableColumns & res_columns, ContextPtr con
         for (auto iterator = db.second->getTablesIterator(context); iterator->isValid(); iterator->next())
         {
             StoragePtr table = iterator->table();
-            if (!table)
+            RocksDBStoragePtr rocksdb_table = table ? std::dynamic_pointer_cast<StorageEmbeddedRocksDB>(table) : nullptr;
+            if (!rocksdb_table)
                 continue;
 
-            if (!dynamic_cast<const StorageEmbeddedRocksDB *>(table.get()))
-                continue;
             if (check_access_for_tables && !access->isGranted(AccessType::SHOW_TABLES, db.first, iterator->name()))
                 continue;
-            tables[db.first][iterator->name()] = table;
-        }
-    }
 
+            tables[db.first][iterator->name()] = rocksdb_table;
+        }
+    }
 
     MutableColumnPtr col_database_mut = ColumnString::create();
     MutableColumnPtr col_table_mut = ColumnString::create();
@@ -101,10 +101,9 @@ void StorageSystemRocksDB::fillData(MutableColumns & res_columns, ContextPtr con
         String database = (*col_database_to_filter)[i].safeGet<const String &>();
         String table = (*col_table_to_filter)[i].safeGet<const String &>();
 
-        auto & rocksdb_table = dynamic_cast<StorageEmbeddedRocksDB &>(*tables[database][table]);
+        auto statistics = tables[database][table]->getRocksDBStatistics();
-        auto statistics = rocksdb_table.getRocksDBStatistics();
         if (!statistics)
-            throw Exception(ErrorCodes::LOGICAL_ERROR, "rocksdb statistics is not enabled");
+            throw Exception(ErrorCodes::LOGICAL_ERROR, "RocksDB statistics are not available");
 
         for (auto [tick, name] : rocksdb::TickersNameMap)
         {

tests/queries/0_stateless/02030_rocksdb_race_long.sh

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+# Tags: race
+
+unset CLICKHOUSE_LOG_COMMENT
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+set -o errexit
+set -o pipefail
+
+echo "
+	DROP TABLE IF EXISTS rocksdb_race;
+	CREATE TABLE rocksdb_race (key String, value UInt32) Engine=EmbeddedRocksDB PRIMARY KEY(key);
+    INSERT INTO rocksdb_race SELECT '1_' || toString(number), number FROM numbers(100000);
+" | $CLICKHOUSE_CLIENT -n
+
+function read_stat_thread()
+{
+    while true; do
+        echo "
+            SELECT * FROM system.rocksdb FORMAT Null;
+        " | $CLICKHOUSE_CLIENT -n
+    done
+}
+
+function truncate_thread()
+{
+    while true; do
+        sleep 3s;
+        echo "
+            TRUNCATE TABLE rocksdb_race;
+        " | $CLICKHOUSE_CLIENT -n
+    done
+}
+
+# https://stackoverflow.com/questions/9954794/execute-a-shell-function-with-timeout
+export -f read_stat_thread;
+export -f truncate_thread;
+
+TIMEOUT=20
+
+timeout $TIMEOUT bash -c read_stat_thread 2> /dev/null &
+timeout $TIMEOUT bash -c truncate_thread 2> /dev/null &
+
+wait
+
+$CLICKHOUSE_CLIENT -q "DROP TABLE rocksdb_race"