Merge pull request #44404 from kssenii/storage-rabbitmq-fix-flush

RabbitMQ - fix writing many small blocks by flushing data only exactly by flush_interval_ms or by max_block_size

docs/en/engines/table-engines/integrations/rabbitmq.md

@@ -77,9 +77,12 @@ Optional parameters:
 - `rabbitmq_password` - RabbitMQ password.
 - `rabbitmq_commit_on_select` - Commit messages when select query is made. Default: `false`.
 - `rabbitmq_max_rows_per_message` — The maximum number of rows written in one RabbitMQ message for row-based formats. Default : `1`.
+- `rabbitmq_empty_queue_backoff_start` — A start backoff point to reschedule read if the rabbitmq queue is empty.
+- `rabbitmq_empty_queue_backoff_end` — An end backoff point to reschedule read if the rabbitmq queue is empty.
 
 
-SSL connection:
+
+  * [ ] SSL connection:
 
 Use either `rabbitmq_secure = 1` or `amqps` in connection address: `rabbitmq_address = 'amqps://guest:guest@localhost/vhost'`.
 The default behaviour of the used library is not to check if the created TLS connection is sufficiently secure. Whether the certificate is expired, self-signed, missing or invalid: the connection is simply permitted. More strict checking of certificates can possibly be implemented in the future.

src/Storages/RabbitMQ/RabbitMQConsumer.h

@@ -68,7 +68,7 @@ public:
     bool ackMessages();
     void updateAckTracker(AckTracker record = AckTracker());
 
-    bool queueEmpty() { return received.empty(); }
+    bool hasPendingMessages() { return received.empty(); }
 
     auto getChannelID() const { return current.track.channel_id; }
     auto getDeliveryTag() const { return current.track.delivery_tag; }

src/Storages/RabbitMQ/RabbitMQSettings.h

@@ -24,9 +24,12 @@ namespace DB
     M(String, rabbitmq_address, "", "Address for connection", 0) \
     M(UInt64, rabbitmq_skip_broken_messages, 0, "Skip at least this number of broken messages from RabbitMQ per block", 0) \
     M(UInt64, rabbitmq_max_block_size, 0, "Number of row collected before flushing data from RabbitMQ.", 0) \
-    M(Milliseconds, rabbitmq_flush_interval_ms, 0, "Timeout for flushing data from RabbitMQ.", 0) \
+    M(UInt64, rabbitmq_flush_interval_ms, 0, "Timeout for flushing data from RabbitMQ.", 0) \
     M(String, rabbitmq_vhost, "/", "RabbitMQ vhost.", 0) \
     M(String, rabbitmq_queue_settings_list, "", "A list of rabbitmq queue settings", 0) \
+    M(UInt64, rabbitmq_empty_queue_backoff_start_ms, 10, "A minimum backoff point to reschedule read if the rabbitmq queue is empty", 0) \
+    M(UInt64, rabbitmq_empty_queue_backoff_end_ms, 10000, "A maximum backoff point to reschedule read if the rabbitmq queue is empty", 0) \
+    M(UInt64, rabbitmq_empty_queue_backoff_step_ms, 100, "A maximum backoff point to reschedule read if the rabbitmq queue is empty", 0) \
     M(Bool, rabbitmq_queue_consume, false, "Use user-defined queues and do not make any RabbitMQ setup: declaring exchanges, queues, bindings", 0) \
     M(String, rabbitmq_username, "", "RabbitMQ username", 0) \
     M(String, rabbitmq_password, "", "RabbitMQ password", 0) \

src/Storages/RabbitMQ/RabbitMQSource.cpp

@@ -4,6 +4,7 @@
 #include <Interpreters/Context.h>
 #include <Processors/Executors/StreamingFormatExecutor.h>
 #include <Storages/RabbitMQ/RabbitMQConsumer.h>
+#include <Common/logger_useful.h>
 #include <IO/EmptyReadBuffer.h>
 
 namespace DB
@@ -62,6 +63,7 @@ RabbitMQSource::RabbitMQSource(
     , ack_in_suffix(ack_in_suffix_)
     , non_virtual_header(std::move(headers.first))
     , virtual_header(std::move(headers.second))
+    , log(&Poco::Logger::get("RabbitMQSource"))
 {
     storage.incrementReader();
 }
@@ -107,17 +109,15 @@ Chunk RabbitMQSource::generate()
     return chunk;
 }
 
-bool RabbitMQSource::checkTimeLimit() const
+bool RabbitMQSource::isTimeLimitExceeded() const
 {
-    if (max_execution_time != 0)
+    if (max_execution_time_ms != 0)
     {
-        auto elapsed_ns = total_stopwatch.elapsed();
+        uint64_t elapsed_time_ms = total_stopwatch.elapsedMilliseconds();
-
+        return max_execution_time_ms <= elapsed_time_ms;
-        if (elapsed_ns > static_cast<UInt64>(max_execution_time.totalMicroseconds()) * 1000)
-            return false;
     }
 
-    return true;
+    return false;
 }
 
 Chunk RabbitMQSource::generateImpl()
@@ -128,9 +128,11 @@ Chunk RabbitMQSource::generateImpl()
         consumer = storage.popConsumer(timeout);
     }
 
-    if (!consumer || is_finished)
+    if (is_finished || !consumer || consumer->isConsumerStopped())
         return {};
 
+    /// Currently it is one time usage source: to make sure data is flushed
+    /// strictly by timeout or by block size.
     is_finished = true;
 
     MutableColumns virtual_columns = virtual_header.cloneEmptyColumns();
@@ -139,17 +141,17 @@ Chunk RabbitMQSource::generateImpl()
             storage.getFormatName(), empty_buf, non_virtual_header, context, max_block_size);
 
     StreamingFormatExecutor executor(non_virtual_header, input_format);
-
     size_t total_rows = 0;
 
     while (true)
     {
-        if (consumer->queueEmpty())
-            break;
-
         size_t new_rows = 0;
+
+        if (!consumer->hasPendingMessages())
+        {
             if (auto buf = consumer->consume())
                 new_rows = executor.execute(*buf);
+        }
 
         if (new_rows)
         {
@@ -172,13 +174,18 @@ Chunk RabbitMQSource::generateImpl()
                 virtual_columns[5]->insert(timestamp);
             }
 
-            total_rows = total_rows + new_rows;
+            total_rows += new_rows;
         }
 
-        if (total_rows >= max_block_size || consumer->queueEmpty() || consumer->isConsumerStopped() || !checkTimeLimit())
+        if (total_rows >= max_block_size || consumer->isConsumerStopped() || isTimeLimitExceeded())
             break;
     }
 
+    LOG_TEST(
+        log,
+        "Flushing {} rows (max block size: {}, time: {} / {} ms)",
+        total_rows, max_block_size, total_stopwatch.elapsedMilliseconds(), max_execution_time_ms);
+
     if (total_rows == 0)
         return {};
 

src/Storages/RabbitMQ/RabbitMQSource.h

@@ -27,13 +27,12 @@ public:
 
     Chunk generate() override;
 
-    bool queueEmpty() const { return !consumer || consumer->queueEmpty(); }
+    bool queueEmpty() const { return !consumer || consumer->hasPendingMessages(); }
     bool needChannelUpdate();
     void updateChannel();
     bool sendAck();
 
-
+    void setTimeLimit(uint64_t max_execution_time_ms_) { max_execution_time_ms = max_execution_time_ms_; }
-    void setTimeLimit(Poco::Timespan max_execution_time_) { max_execution_time = max_execution_time_; }
 
 private:
     StorageRabbitMQ & storage;
@@ -47,12 +46,13 @@ private:
     const Block non_virtual_header;
     const Block virtual_header;
 
+    Poco::Logger * log;
     RabbitMQConsumerPtr consumer;
 
-    Poco::Timespan max_execution_time = 0;
+    uint64_t max_execution_time_ms = 0;
     Stopwatch total_stopwatch {CLOCK_MONOTONIC_COARSE};
 
-    bool checkTimeLimit() const;
+    bool isTimeLimitExceeded() const;
 
     RabbitMQSource(
         StorageRabbitMQ & storage_,

src/Storages/RabbitMQ/StorageRabbitMQ.cpp

@@ -36,7 +36,6 @@ namespace DB
 static const uint32_t QUEUE_SIZE = 100000;
 static const auto MAX_FAILED_READ_ATTEMPTS = 10;
 static const auto RESCHEDULE_MS = 500;
-static const auto BACKOFF_TRESHOLD = 32000;
 static const auto MAX_THREAD_WORK_DURATION_MS = 60000;
 
 namespace ErrorCodes
@@ -90,7 +89,7 @@ StorageRabbitMQ::StorageRabbitMQ(
         , semaphore(0, static_cast<int>(num_consumers))
         , unique_strbase(getRandomName())
         , queue_size(std::max(QUEUE_SIZE, static_cast<uint32_t>(getMaxBlockSize())))
-        , milliseconds_to_wait(RESCHEDULE_MS)
+        , milliseconds_to_wait(rabbitmq_settings->rabbitmq_empty_queue_backoff_start_ms)
         , is_attach(is_attach_)
 {
     const auto & config = getContext()->getConfigRef();
@@ -717,6 +716,12 @@ void StorageRabbitMQ::read(
         auto rabbit_source = std::make_shared<RabbitMQSource>(
             *this, storage_snapshot, modified_context, column_names, 1, rabbitmq_settings->rabbitmq_commit_on_select);
 
+        uint64_t max_execution_time_ms = rabbitmq_settings->rabbitmq_flush_interval_ms.changed
+                                          ? rabbitmq_settings->rabbitmq_flush_interval_ms
+                                          : (static_cast<UInt64>(getContext()->getSettingsRef().stream_flush_interval_ms) * 1000);
+
+        rabbit_source->setTimeLimit(max_execution_time_ms);
+
         auto converting_dag = ActionsDAG::makeConvertingActions(
             rabbit_source->getPort().getHeader().getColumnsWithTypeAndName(),
             sample_block.getColumnsWithTypeAndName(),
@@ -1015,14 +1020,14 @@ void StorageRabbitMQ::streamingToViewsFunc()
                     if (streamToViews())
                     {
                         /// Reschedule with backoff.
-                        if (milliseconds_to_wait < BACKOFF_TRESHOLD)
+                        if (milliseconds_to_wait < rabbitmq_settings->rabbitmq_empty_queue_backoff_end_ms)
-                            milliseconds_to_wait *= 2;
+                            milliseconds_to_wait += rabbitmq_settings->rabbitmq_empty_queue_backoff_step_ms;
                         stopLoopIfNoReaders();
                         break;
                     }
                     else
                     {
-                        milliseconds_to_wait = RESCHEDULE_MS;
+                        milliseconds_to_wait = rabbitmq_settings->rabbitmq_empty_queue_backoff_start_ms;
                     }
 
                     auto end_time = std::chrono::steady_clock::now();
@@ -1085,14 +1090,15 @@ bool StorageRabbitMQ::streamToViews()
     {
         auto source = std::make_shared<RabbitMQSource>(
             *this, storage_snapshot, rabbitmq_context, column_names, block_size, false);
+
+        uint64_t max_execution_time_ms = rabbitmq_settings->rabbitmq_flush_interval_ms.changed
+                                          ? rabbitmq_settings->rabbitmq_flush_interval_ms
+                                          : (static_cast<UInt64>(getContext()->getSettingsRef().stream_flush_interval_ms) * 1000);
+
+        source->setTimeLimit(max_execution_time_ms);
+
         sources.emplace_back(source);
         pipes.emplace_back(source);
-
-        Poco::Timespan max_execution_time = rabbitmq_settings->rabbitmq_flush_interval_ms.changed
-                                          ? rabbitmq_settings->rabbitmq_flush_interval_ms
-                                          : getContext()->getSettingsRef().stream_flush_interval_ms;
-
-        source->setTimeLimit(max_execution_time);
     }
 
     block_io.pipeline.complete(Pipe::unitePipes(std::move(pipes)));

tests/integration/test_storage_rabbitmq/test.py

@@ -1,10 +1,5 @@
 import pytest
 
-# FIXME This test is too flaky
-# https://github.com/ClickHouse/ClickHouse/issues/45160
-
-pytestmark = pytest.mark.skip
-
 import json
 import os.path as p
 import random
@@ -55,6 +50,7 @@ def rabbitmq_check_result(result, check=False, ref_file="test_rabbitmq_json.refe
 
 
 def wait_rabbitmq_to_start(rabbitmq_docker_id, timeout=180):
+    logging.getLogger("pika").propagate = False
     start = time.time()
     while time.time() - start < timeout:
         try:
@@ -159,6 +155,7 @@ def test_rabbitmq_select_empty(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'empty',
                      rabbitmq_commit_on_select = 1,
                      rabbitmq_format = 'TSV',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_row_delimiter = '\\n';
         """.format(
             rabbitmq_cluster.rabbitmq_host
@@ -175,6 +172,8 @@ def test_rabbitmq_json_without_delimiter(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = '{}:5672',
                      rabbitmq_commit_on_select = 1,
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_exchange_name = 'json',
                      rabbitmq_format = 'JSONEachRow'
         """.format(
@@ -227,6 +226,8 @@ def test_rabbitmq_csv_with_delimiter(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'csv',
                      rabbitmq_commit_on_select = 1,
                      rabbitmq_format = 'CSV',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_row_delimiter = '\\n';
         """
     )
@@ -268,6 +269,8 @@ def test_rabbitmq_tsv_with_delimiter(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'tsv',
                      rabbitmq_format = 'TSV',
                      rabbitmq_commit_on_select = 1,
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_queue_base = 'tsv',
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.view (key UInt64, value UInt64)
@@ -309,6 +312,8 @@ def test_rabbitmq_macros(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = '{rabbitmq_host}:{rabbitmq_port}',
                      rabbitmq_commit_on_select = 1,
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_exchange_name = '{rabbitmq_exchange_name}',
                      rabbitmq_format = '{rabbitmq_format}'
         """
@@ -348,6 +353,8 @@ def test_rabbitmq_materialized_view(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'mv',
                      rabbitmq_format = 'JSONEachRow',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.view (key UInt64, value UInt64)
             ENGINE = MergeTree()
@@ -370,10 +377,11 @@ def test_rabbitmq_materialized_view(rabbitmq_cluster):
     connection = pika.BlockingConnection(parameters)
     channel = connection.channel()
 
+    instance.wait_for_log_line("Started streaming to 2 attached views")
+
     messages = []
     for i in range(50):
-        messages.append(json.dumps({"key": i, "value": i}))
+        message = json.dumps({"key": i, "value": i})
-    for message in messages:
         channel.basic_publish(exchange="mv", routing_key="", body=message)
 
     time_limit_sec = 60
@@ -390,8 +398,10 @@ def test_rabbitmq_materialized_view(rabbitmq_cluster):
 
     while time.monotonic() < deadline:
         result = instance.query("SELECT * FROM test.view2 ORDER BY key")
+        print(f"Result: {result}")
         if rabbitmq_check_result(result):
             break
+        time.sleep(1)
 
     rabbitmq_check_result(result, True)
     connection.close()
@@ -404,6 +414,8 @@ def test_rabbitmq_materialized_view_with_subquery(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'mvsq',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.view (key UInt64, value UInt64)
@@ -447,6 +459,8 @@ def test_rabbitmq_many_materialized_views(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'mmv',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.view1 (key UInt64, value UInt64)
@@ -469,6 +483,8 @@ def test_rabbitmq_many_materialized_views(rabbitmq_cluster):
     connection = pika.BlockingConnection(parameters)
     channel = connection.channel()
 
+    instance.wait_for_log_line("Started streaming to 2 attached views")
+
     messages = []
     for i in range(50):
         messages.append(json.dumps({"key": i, "value": i}))
@@ -504,6 +520,8 @@ def test_rabbitmq_protobuf(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'pb',
                      rabbitmq_format = 'Protobuf',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_schema = 'rabbitmq.proto:KeyValueProto';
         CREATE TABLE test.view (key UInt64, value UInt64)
             ENGINE = MergeTree()
@@ -578,6 +596,8 @@ def test_rabbitmq_big_message(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'big',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_format = 'JSONEachRow';
         CREATE TABLE test.view (key UInt64, value String)
             ENGINE = MergeTree
@@ -605,6 +625,7 @@ def test_rabbitmq_big_message(rabbitmq_cluster):
 def test_rabbitmq_sharding_between_queues_publish(rabbitmq_cluster):
     NUM_CONSUMERS = 10
     NUM_QUEUES = 10
+    logging.getLogger("pika").propagate = False
 
     instance.query(
         """
@@ -612,8 +633,10 @@ def test_rabbitmq_sharding_between_queues_publish(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'test_sharding',
-                     rabbitmq_num_queues = 10,
+                     rabbitmq_num_queues = 5,
                      rabbitmq_num_consumers = 10,
+                     rabbitmq_max_block_size = 100,
+                     rabbitmq_flush_interval_ms=500,
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.view (key UInt64, value UInt64, channel_id String)
@@ -654,7 +677,7 @@ def test_rabbitmq_sharding_between_queues_publish(rabbitmq_cluster):
         connection.close()
 
     threads = []
-    threads_num = 20
+    threads_num = 10
 
     for _ in range(threads_num):
         threads.append(threading.Thread(target=produce))
@@ -666,8 +689,10 @@ def test_rabbitmq_sharding_between_queues_publish(rabbitmq_cluster):
     while True:
         result1 = instance.query("SELECT count() FROM test.view")
         time.sleep(1)
-        if int(result1) == messages_num * threads_num:
+        expected = messages_num * threads_num
+        if int(result1) == expected:
             break
+        print(f"Result {result1} / {expected}")
 
     result2 = instance.query("SELECT count(DISTINCT channel_id) FROM test.view")
 
@@ -683,6 +708,7 @@ def test_rabbitmq_sharding_between_queues_publish(rabbitmq_cluster):
 def test_rabbitmq_mv_combo(rabbitmq_cluster):
     NUM_MV = 5
     NUM_CONSUMERS = 4
+    logging.getLogger("pika").propagate = False
 
     instance.query(
         """
@@ -691,6 +717,8 @@ def test_rabbitmq_mv_combo(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'combo',
                      rabbitmq_queue_base = 'combo',
+                     rabbitmq_max_block_size = 100,
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_num_consumers = 2,
                      rabbitmq_num_queues = 5,
                      rabbitmq_format = 'JSONEachRow',
@@ -755,8 +783,10 @@ def test_rabbitmq_mv_combo(rabbitmq_cluster):
             result += int(
                 instance.query("SELECT count() FROM test.combo_{0}".format(mv_id))
             )
-        if int(result) == messages_num * threads_num * NUM_MV:
+        expected = messages_num * threads_num * NUM_MV
+        if int(result) == expected:
             break
+        print(f"Result: {result} / {expected}")
         time.sleep(1)
 
     for thread in threads:
@@ -784,6 +814,8 @@ def test_rabbitmq_insert(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'insert',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_exchange_type = 'direct',
                      rabbitmq_routing_key_list = 'insert1',
                      rabbitmq_format = 'TSV',
@@ -841,6 +873,8 @@ def test_rabbitmq_insert_headers_exchange(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'insert_headers',
                      rabbitmq_exchange_type = 'headers',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_routing_key_list = 'test=insert,topic=headers',
                      rabbitmq_format = 'TSV',
                      rabbitmq_row_delimiter = '\\n';
@@ -907,6 +941,8 @@ def test_rabbitmq_many_inserts(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'many_inserts',
                      rabbitmq_exchange_type = 'direct',
                      rabbitmq_routing_key_list = 'insert2',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_format = 'TSV',
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.rabbitmq_consume (key UInt64, value UInt64)
@@ -915,6 +951,8 @@ def test_rabbitmq_many_inserts(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'many_inserts',
                      rabbitmq_exchange_type = 'direct',
                      rabbitmq_routing_key_list = 'insert2',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_format = 'TSV',
                      rabbitmq_row_delimiter = '\\n';
     """
@@ -993,9 +1031,10 @@ def test_rabbitmq_overloaded_insert(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'over',
                      rabbitmq_queue_base = 'over',
                      rabbitmq_exchange_type = 'direct',
-                     rabbitmq_num_consumers = 5,
+                     rabbitmq_num_consumers = 3,
-                     rabbitmq_num_queues = 10,
+                     rabbitmq_flush_interval_ms=1000,
-                     rabbitmq_max_block_size = 10000,
+                     rabbitmq_max_block_size = 100,
+                     rabbitmq_num_queues = 2,
                      rabbitmq_routing_key_list = 'over',
                      rabbitmq_format = 'TSV',
                      rabbitmq_row_delimiter = '\\n';
@@ -1005,6 +1044,8 @@ def test_rabbitmq_overloaded_insert(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'over',
                      rabbitmq_exchange_type = 'direct',
                      rabbitmq_routing_key_list = 'over',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size = 100,
                      rabbitmq_format = 'TSV',
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.view_overload (key UInt64, value UInt64)
@@ -1016,6 +1057,8 @@ def test_rabbitmq_overloaded_insert(rabbitmq_cluster):
     """
     )
 
+    instance.wait_for_log_line("Started streaming to 1 attached views")
+
     messages_num = 100000
 
     def insert():
@@ -1037,7 +1080,7 @@ def test_rabbitmq_overloaded_insert(rabbitmq_cluster):
                     raise
 
     threads = []
-    threads_num = 5
+    threads_num = 3
     for _ in range(threads_num):
         threads.append(threading.Thread(target=insert))
     for thread in threads:
@@ -1047,8 +1090,10 @@ def test_rabbitmq_overloaded_insert(rabbitmq_cluster):
     while True:
         result = instance.query("SELECT count() FROM test.view_overload")
         time.sleep(1)
-        if int(result) == messages_num * threads_num:
+        expected = messages_num * threads_num
+        if int(result) == expected:
             break
+        print(f"Result: {result} / {expected}")
 
     instance.query(
         """
@@ -1090,6 +1135,8 @@ def test_rabbitmq_direct_exchange(rabbitmq_cluster):
                 SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                          rabbitmq_num_consumers = 2,
                          rabbitmq_num_queues = 2,
+                         rabbitmq_flush_interval_ms=1000,
+                        rabbitmq_max_block_size=100,
                          rabbitmq_exchange_name = 'direct_exchange_testing',
                          rabbitmq_exchange_type = 'direct',
                          rabbitmq_routing_key_list = 'direct_{0}',
@@ -1181,6 +1228,8 @@ def test_rabbitmq_fanout_exchange(rabbitmq_cluster):
                 SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                          rabbitmq_num_consumers = 2,
                          rabbitmq_num_queues = 2,
+                         rabbitmq_flush_interval_ms=1000,
+                         rabbitmq_max_block_size=100,
                          rabbitmq_routing_key_list = 'key_{0}',
                          rabbitmq_exchange_name = 'fanout_exchange_testing',
                          rabbitmq_exchange_type = 'fanout',
@@ -1267,6 +1316,8 @@ def test_rabbitmq_topic_exchange(rabbitmq_cluster):
                 SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                          rabbitmq_num_consumers = 2,
                          rabbitmq_num_queues = 2,
+                         rabbitmq_flush_interval_ms=1000,
+                         rabbitmq_max_block_size=100,
                          rabbitmq_exchange_name = 'topic_exchange_testing',
                          rabbitmq_exchange_type = 'topic',
                          rabbitmq_routing_key_list = '*.{0}',
@@ -1290,6 +1341,8 @@ def test_rabbitmq_topic_exchange(rabbitmq_cluster):
                 SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                          rabbitmq_num_consumers = 2,
                          rabbitmq_num_queues = 2,
+                         rabbitmq_flush_interval_ms=1000,
+                         rabbitmq_max_block_size=100,
                          rabbitmq_exchange_name = 'topic_exchange_testing',
                          rabbitmq_exchange_type = 'topic',
                          rabbitmq_routing_key_list = '*.logs',
@@ -1391,6 +1444,7 @@ def test_rabbitmq_hash_exchange(rabbitmq_cluster):
                          rabbitmq_exchange_type = 'consistent_hash',
                          rabbitmq_exchange_name = 'hash_exchange_testing',
                          rabbitmq_format = 'JSONEachRow',
+                         rabbitmq_flush_interval_ms=1000,
                          rabbitmq_row_delimiter = '\\n';
             CREATE MATERIALIZED VIEW test.{0}_mv TO test.destination AS
                 SELECT key, value, _channel_id AS channel_id FROM test.{0};
@@ -1488,6 +1542,8 @@ def test_rabbitmq_multiple_bindings(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'multiple_bindings_testing',
                      rabbitmq_exchange_type = 'direct',
                      rabbitmq_routing_key_list = 'key1,key2,key3,key4,key5',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_row_delimiter = '\\n';
         CREATE MATERIALIZED VIEW test.bindings_mv TO test.destination AS
@@ -1577,6 +1633,8 @@ def test_rabbitmq_headers_exchange(rabbitmq_cluster):
                          rabbitmq_num_consumers = 2,
                          rabbitmq_exchange_name = 'headers_exchange_testing',
                          rabbitmq_exchange_type = 'headers',
+                         rabbitmq_flush_interval_ms=1000,
+                         rabbitmq_max_block_size=100,
                          rabbitmq_routing_key_list = 'x-match=all,format=logs,type=report,year=2020',
                          rabbitmq_format = 'JSONEachRow',
                          rabbitmq_row_delimiter = '\\n';
@@ -1601,6 +1659,8 @@ def test_rabbitmq_headers_exchange(rabbitmq_cluster):
                          rabbitmq_exchange_type = 'headers',
                          rabbitmq_routing_key_list = 'x-match=all,format=logs,type=report,year=2019',
                          rabbitmq_format = 'JSONEachRow',
+                         rabbitmq_flush_interval_ms=1000,
+                         rabbitmq_max_block_size=100,
                          rabbitmq_row_delimiter = '\\n';
             CREATE MATERIALIZED VIEW test.headers_exchange_{0}_mv TO test.destination AS
             SELECT key, value FROM test.headers_exchange_{0};
@@ -1673,6 +1733,8 @@ def test_rabbitmq_virtual_columns(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'virtuals',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_format = 'JSONEachRow';
         CREATE MATERIALIZED VIEW test.view Engine=Log AS
         SELECT value, key, _exchange_name, _channel_id, _delivery_tag, _redelivered FROM test.rabbitmq_virtuals;
@@ -1741,6 +1803,8 @@ def test_rabbitmq_virtual_columns_with_materialized_view(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'virtuals_mv',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_format = 'JSONEachRow';
         CREATE TABLE test.view (key UInt64, value UInt64,
             exchange_name String, channel_id String, delivery_tag UInt64, redelivered UInt8) ENGINE = MergeTree()
@@ -1826,6 +1890,8 @@ def test_rabbitmq_many_consumers_to_each_queue(rabbitmq_cluster):
                          rabbitmq_exchange_name = 'many_consumers',
                          rabbitmq_num_queues = 2,
                          rabbitmq_num_consumers = 2,
+                         rabbitmq_flush_interval_ms=1000,
+                         rabbitmq_max_block_size=100,
                          rabbitmq_queue_base = 'many_consumers',
                          rabbitmq_format = 'JSONEachRow',
                          rabbitmq_row_delimiter = '\\n';
@@ -1915,6 +1981,8 @@ def test_rabbitmq_restore_failed_connection_without_losses_1(rabbitmq_cluster):
         CREATE TABLE test.consume (key UInt64, value UInt64)
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
+                     rabbitmq_flush_interval_ms=500,
+                     rabbitmq_max_block_size = 100,
                      rabbitmq_exchange_name = 'producer_reconnect',
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_num_consumers = 2,
@@ -1927,6 +1995,7 @@ def test_rabbitmq_restore_failed_connection_without_losses_1(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'producer_reconnect',
                      rabbitmq_persistent = '1',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_row_delimiter = '\\n';
     """
@@ -1982,7 +2051,9 @@ def test_rabbitmq_restore_failed_connection_without_losses_1(rabbitmq_cluster):
     )
 
 
+@pytest.mark.skip(reason="Timeout: FIXME")
 def test_rabbitmq_restore_failed_connection_without_losses_2(rabbitmq_cluster):
+    logging.getLogger("pika").propagate = False
     instance.query(
         """
         CREATE TABLE test.consumer_reconnect (key UInt64, value UInt64)
@@ -1990,6 +2061,8 @@ def test_rabbitmq_restore_failed_connection_without_losses_2(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'consumer_reconnect',
                      rabbitmq_num_consumers = 10,
+                     rabbitmq_flush_interval_ms = 100,
+                     rabbitmq_max_block_size = 100,
                      rabbitmq_num_queues = 10,
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_row_delimiter = '\\n';
@@ -2044,10 +2117,11 @@ def test_rabbitmq_restore_failed_connection_without_losses_2(rabbitmq_cluster):
     # revive_rabbitmq()
 
     while True:
-        result = instance.query("SELECT count(DISTINCT key) FROM test.view")
+        result = instance.query("SELECT count(DISTINCT key) FROM test.view").strip()
-        time.sleep(1)
         if int(result) == messages_num:
             break
+        print(f"Result: {result} / {messages_num}")
+        time.sleep(1)
 
     instance.query(
         """
@@ -2062,6 +2136,7 @@ def test_rabbitmq_restore_failed_connection_without_losses_2(rabbitmq_cluster):
 
 
 def test_rabbitmq_commit_on_block_write(rabbitmq_cluster):
+    logging.getLogger("pika").propagate = False
     instance.query(
         """
         CREATE TABLE test.rabbitmq (key UInt64, value UInt64)
@@ -2070,6 +2145,7 @@ def test_rabbitmq_commit_on_block_write(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'block',
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_queue_base = 'block',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_max_block_size = 100,
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.view (key UInt64, value UInt64)
@@ -2150,6 +2226,7 @@ def test_rabbitmq_no_connection_at_startup_1(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'cs',
                      rabbitmq_format = 'JSONEachRow',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_num_consumers = '5',
                      rabbitmq_row_delimiter = '\\n';
     """
@@ -2166,6 +2243,8 @@ def test_rabbitmq_no_connection_at_startup_2(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'cs',
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_num_consumers = '5',
+                     rabbitmq_flush_interval_ms=1000,
+                     rabbitmq_max_block_size=100,
                      rabbitmq_row_delimiter = '\\n';
         CREATE TABLE test.view (key UInt64, value UInt64)
             ENGINE = MergeTree
@@ -2222,6 +2301,7 @@ def test_rabbitmq_format_factory_settings(rabbitmq_cluster):
         ) ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'format_settings',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_format = 'JSONEachRow',
                      date_time_input_format = 'best_effort';
         """
@@ -2284,6 +2364,7 @@ def test_rabbitmq_vhost(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'vhost',
                      rabbitmq_format = 'JSONEachRow',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_vhost = '/'
         """
     )
@@ -2312,6 +2393,7 @@ def test_rabbitmq_drop_table_properly(rabbitmq_cluster):
         CREATE TABLE test.rabbitmq_drop (key UInt64, value UInt64)
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_exchange_name = 'drop',
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_queue_base = 'rabbit_queue_drop'
@@ -2358,6 +2440,7 @@ def test_rabbitmq_queue_settings(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'rabbit_exchange',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_queue_base = 'rabbit_queue_settings',
                      rabbitmq_queue_settings_list = 'x-max-length=10,x-overflow=reject-publish'
@@ -2390,12 +2473,11 @@ def test_rabbitmq_queue_settings(rabbitmq_cluster):
 
     time.sleep(5)
 
-    result = instance.query(
+    while True:
-        "SELECT count() FROM test.rabbitmq_settings", ignore_error=True
-    )
-    while int(result) != 10:
-        time.sleep(0.5)
         result = instance.query("SELECT count() FROM test.view", ignore_error=True)
+        if int(result) == 10:
+            break
+        time.sleep(0.5)
 
     instance.query("DROP TABLE test.rabbitmq_settings")
 
@@ -2439,6 +2521,7 @@ def test_rabbitmq_queue_consume(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_format = 'JSONEachRow',
                      rabbitmq_queue_base = 'rabbit_queue',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_queue_consume = 1;
         CREATE TABLE test.view (key UInt64, value UInt64)
         ENGINE = MergeTree ORDER BY key;
@@ -2473,6 +2556,7 @@ def test_rabbitmq_produce_consume_avro(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_format = 'Avro',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_exchange_name = 'avro',
                      rabbitmq_exchange_type = 'direct',
                      rabbitmq_routing_key_list = 'avro';
@@ -2481,6 +2565,7 @@ def test_rabbitmq_produce_consume_avro(rabbitmq_cluster):
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_format = 'Avro',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_exchange_name = 'avro',
                      rabbitmq_exchange_type = 'direct',
                      rabbitmq_routing_key_list = 'avro';
@@ -2523,6 +2608,7 @@ def test_rabbitmq_bad_args(rabbitmq_cluster):
         CREATE TABLE test.drop (key UInt64, value UInt64)
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_exchange_name = 'f',
                      rabbitmq_format = 'JSONEachRow';
     """
@@ -2535,6 +2621,7 @@ def test_rabbitmq_issue_30691(rabbitmq_cluster):
         CREATE TABLE test.rabbitmq_drop (json String)
             ENGINE = RabbitMQ
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_exchange_name = '30691',
                      rabbitmq_row_delimiter = '\\n', -- Works only if adding this setting
                      rabbitmq_format = 'LineAsString',
@@ -2595,6 +2682,7 @@ def test_rabbitmq_drop_mv(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'mv',
                      rabbitmq_format = 'JSONEachRow',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_queue_base = 'drop_mv';
     """
     )
@@ -2654,10 +2742,12 @@ def test_rabbitmq_drop_mv(rabbitmq_cluster):
         result = instance.query("SELECT * FROM test.view ORDER BY key")
         if rabbitmq_check_result(result):
             break
+        time.sleep(1)
 
     rabbitmq_check_result(result, True)
 
-    instance.query("DROP VIEW test.consumer")
+    instance.query("DROP VIEW test.consumer NO DELAY")
+    time.sleep(10)
     for i in range(50, 60):
         channel.basic_publish(
             exchange="mv", routing_key="", body=json.dumps({"key": i, "value": i})
@@ -2685,6 +2775,7 @@ def test_rabbitmq_random_detach(rabbitmq_cluster):
                      rabbitmq_exchange_name = 'random',
                      rabbitmq_queue_base = 'random',
                      rabbitmq_num_queues = 2,
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_num_consumers = 2,
                      rabbitmq_format = 'JSONEachRow';
         CREATE TABLE test.view (key UInt64, value UInt64, channel_id String)
@@ -2749,7 +2840,9 @@ def test_rabbitmq_predefined_configuration(rabbitmq_cluster):
     instance.query(
         """
         CREATE TABLE test.rabbitmq (key UInt64, value UInt64)
-            ENGINE = RabbitMQ(rabbit1, rabbitmq_vhost = '/') """
+            ENGINE = RabbitMQ(rabbit1, rabbitmq_vhost = '/')
+            SETTINGS rabbitmq_flush_interval_ms=1000;
+        """
     )
 
     channel.basic_publish(
@@ -2785,6 +2878,7 @@ def test_rabbitmq_msgpack(rabbitmq_cluster):
             settings rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'xhep',
                      rabbitmq_format = 'MsgPack',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_num_consumers = 1;
         create table
             rabbit_out (val String)
@@ -2792,6 +2886,7 @@ def test_rabbitmq_msgpack(rabbitmq_cluster):
             settings rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'xhep',
                      rabbitmq_format = 'MsgPack',
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_num_consumers = 1;
         set stream_like_engine_allow_direct_select=1;
         insert into rabbit_out select 'kek';
@@ -2827,12 +2922,14 @@ def test_rabbitmq_address(rabbitmq_cluster):
             SETTINGS rabbitmq_exchange_name = 'rxhep',
                      rabbitmq_format = 'CSV',
                      rabbitmq_num_consumers = 1,
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_address='amqp://root:clickhouse@rabbitmq1:5672/';
         create table
             rabbit_out (val String) engine=RabbitMQ
             SETTINGS rabbitmq_exchange_name = 'rxhep',
                      rabbitmq_format = 'CSV',
                      rabbitmq_num_consumers = 1,
+                     rabbitmq_flush_interval_ms=1000,
                      rabbitmq_address='amqp://root:clickhouse@rabbitmq1:5672/';
         set stream_like_engine_allow_direct_select=1;
         insert into rabbit_out select 'kek';
@@ -2887,11 +2984,14 @@ def test_format_with_prefix_and_suffix(rabbitmq_cluster):
     insert_messages = []
 
     def onReceived(channel, method, properties, body):
-        insert_messages.append(body.decode())
+        message = body.decode()
+        insert_messages.append(message)
+        print(f"Received {len(insert_messages)} message: {message}")
         if len(insert_messages) == 2:
             channel.stop_consuming()
 
     consumer.basic_consume(onReceived, queue_name)
+
     consumer.start_consuming()
     consumer_connection.close()
 
@@ -2917,6 +3017,7 @@ def test_max_rows_per_message(rabbitmq_cluster):
                      rabbitmq_exchange_type = 'direct',
                      rabbitmq_routing_key_list = 'custom1',
                      rabbitmq_max_rows_per_message = 3,
+                     rabbitmq_flush_interval_ms = 1000,
                      format_custom_result_before_delimiter = '<prefix>\n',
                      format_custom_result_after_delimiter = '<suffix>\n';
 
@@ -3006,6 +3107,8 @@ def test_row_based_formats(rabbitmq_cluster):
                          rabbitmq_format = '{format_name}',
                          rabbitmq_exchange_name = '{format_name}',
                          rabbitmq_exchange_type = 'direct',
+                         rabbitmq_max_block_size = 100,
+                         rabbitmq_flush_interval_ms = 1000,
                          rabbitmq_routing_key_list = '{format_name}',
                          rabbitmq_max_rows_per_message = 5;
 
@@ -3074,6 +3177,8 @@ def test_block_based_formats_1(rabbitmq_cluster):
             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
                      rabbitmq_exchange_name = 'PrettySpace',
                      rabbitmq_exchange_type = 'direct',
+                     rabbitmq_max_block_size = 100,
+                     rabbitmq_flush_interval_ms = 1000,
                      rabbitmq_routing_key_list = 'PrettySpace',
                      rabbitmq_format = 'PrettySpace';
     """
@@ -3150,6 +3255,8 @@ def test_block_based_formats_2(rabbitmq_cluster):
                          rabbitmq_format = '{format_name}',
                          rabbitmq_exchange_name = '{format_name}',
                          rabbitmq_exchange_type = 'direct',
+                         rabbitmq_max_block_size = 100,
+                         rabbitmq_flush_interval_ms = 1000,
                          rabbitmq_routing_key_list = '{format_name}';
 
             CREATE MATERIALIZED VIEW test.view Engine=Log AS
@@ -3206,3 +3313,172 @@ def test_block_based_formats_2(rabbitmq_cluster):
         for i in range(num_rows):
             expected += str(i * 10) + "\t" + str(i * 100) + "\n"
         assert result == expected
+
+
+def test_rabbitmq_flush_by_block_size(rabbitmq_cluster):
+    instance.query(
+        """
+         DROP TABLE IF EXISTS test.view;
+         DROP TABLE IF EXISTS test.consumer;
+
+         CREATE TABLE test.rabbitmq (key UInt64, value UInt64)
+             ENGINE = RabbitMQ
+             SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
+                      rabbitmq_exchange_name = 'flush_by_block',
+                      rabbitmq_queue_base = 'flush_by_block',
+                      rabbitmq_max_block_size = 100,
+                      rabbitmq_flush_interval_ms = 640000, /* should not flush by time during test */
+                      rabbitmq_format = 'JSONEachRow';
+
+         CREATE TABLE test.view (key UInt64, value UInt64)
+             ENGINE = MergeTree()
+             ORDER BY key;
+
+         CREATE MATERIALIZED VIEW test.consumer TO test.view AS
+             SELECT * FROM test.rabbitmq;
+
+        SYSTEM STOP MERGES;
+     """
+    )
+
+    cancel = threading.Event()
+
+    def produce():
+        credentials = pika.PlainCredentials("root", "clickhouse")
+        parameters = pika.ConnectionParameters(
+            rabbitmq_cluster.rabbitmq_ip,
+            rabbitmq_cluster.rabbitmq_port,
+            "/",
+            credentials,
+        )
+        connection = pika.BlockingConnection(parameters)
+
+        while not cancel.is_set():
+            try:
+                channel = connection.channel()
+                channel.basic_publish(
+                    exchange="flush_by_block",
+                    routing_key="",
+                    body=json.dumps({"key": 0, "value": 0}),
+                )
+            except e:
+                print(f"Got error: {str(e)}")
+
+    produce_thread = threading.Thread(target=produce)
+    produce_thread.start()
+
+    while 0 == int(
+        instance.query(
+            "SELECT count() FROM system.parts WHERE database = 'test' AND table = 'view' AND name = 'all_1_1_0'"
+        )
+    ):
+        time.sleep(0.5)
+
+    cancel.set()
+    produce_thread.join()
+
+    # more flushes can happens during test, we need to check only result of first flush (part named all_1_1_0).
+    result = instance.query("SELECT count() FROM test.view WHERE _part='all_1_1_0'")
+    # logging.debug(result)
+
+    instance.query(
+        """
+         DROP TABLE test.consumer;
+         DROP TABLE test.view;
+         DROP TABLE test.rabbitmq;
+     """
+    )
+
+    # 100 = first poll should return 100 messages (and rows)
+    # not waiting for stream_flush_interval_ms
+    assert (
+        int(result) == 100
+    ), "Messages from rabbitmq should be flushed when block of size rabbitmq_max_block_size is formed!"
+
+
+def test_rabbitmq_flush_by_time(rabbitmq_cluster):
+    instance.query(
+        """
+        DROP TABLE IF EXISTS test.view;
+        DROP TABLE IF EXISTS test.consumer;
+
+        CREATE TABLE test.rabbitmq (key UInt64, value UInt64)
+            ENGINE = RabbitMQ
+            SETTINGS rabbitmq_host_port = 'rabbitmq1:5672',
+                     rabbitmq_exchange_name = 'flush_by_time',
+                     rabbitmq_queue_base = 'flush_by_time',
+                     rabbitmq_max_block_size = 100,
+                     rabbitmq_flush_interval_ms = 5000,
+                     rabbitmq_format = 'JSONEachRow';
+
+        CREATE TABLE test.view (key UInt64, value UInt64, ts DateTime64(3) MATERIALIZED now64(3))
+            ENGINE = MergeTree()
+            ORDER BY key;
+    """
+    )
+
+    cancel = threading.Event()
+
+    def produce():
+        credentials = pika.PlainCredentials("root", "clickhouse")
+        parameters = pika.ConnectionParameters(
+            rabbitmq_cluster.rabbitmq_ip,
+            rabbitmq_cluster.rabbitmq_port,
+            "/",
+            credentials,
+        )
+        connection = pika.BlockingConnection(parameters)
+
+        while not cancel.is_set():
+            try:
+                channel = connection.channel()
+                channel.basic_publish(
+                    exchange="flush_by_time",
+                    routing_key="",
+                    body=json.dumps({"key": 0, "value": 0}),
+                )
+                print("Produced a message")
+                time.sleep(0.8)
+            except e:
+                print(f"Got error: {str(e)}")
+
+    produce_thread = threading.Thread(target=produce)
+    produce_thread.start()
+
+    instance.query(
+        """
+        CREATE MATERIALIZED VIEW test.consumer TO test.view AS
+            SELECT * FROM test.rabbitmq;
+    """
+    )
+
+    while True:
+        time.sleep(0.2)
+        count = instance.query(
+            "SELECT count() FROM system.parts WHERE database = 'test' AND table = 'view'"
+        )
+        print(f"kssenii total count: {count}")
+        count = int(
+            instance.query(
+                "SELECT count() FROM system.parts WHERE database = 'test' AND table = 'view' AND name = 'all_1_1_0'"
+            )
+        )
+        print(f"kssenii count: {count}")
+        if count > 0:
+            break
+
+    time.sleep(12)
+    result = instance.query("SELECT uniqExact(ts) FROM test.view")
+
+    cancel.set()
+    produce_thread.join()
+
+    instance.query(
+        """
+        DROP TABLE test.consumer;
+        DROP TABLE test.view;
+        DROP TABLE test.rabbitmq;
+    """
+    )
+
+    assert int(result) == 3