In case of Buffer table has columns of AggregateFunction type,
aggregate states for such columns will be allocated from the query
context but those states can be destroyed from the server context (in
case of background flush), and thus memory will be leaked from the query
since aggregate states can be shared, and eventually this will lead to
MEMORY_LIMIT_EXCEEDED error.
To avoid this, prohibit sharing the aggregate states.
But note, that this problem only about memory accounting, not memory
usage itself.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
* Use INITIAL_QUERY for clickhouse-benchmark
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
* Fix parallel_reading_from_replicas with clickhouse-bechmark
Before it produces the following error:
$ clickhouse-benchmark --stacktrace -i1 --query "select * from remote('127.1', default.data_mt) limit 10" --allow_experimental_parallel_reading_from_replicas=1 --max_parallel_replicas=3
Loaded 1 queries.
Logical error: 'Coordinator for parallel reading from replicas is not initialized'.
Aborted (core dumped)
Since it uses the same code, i.e RemoteQueryExecutor ->
MultiplexedConnections, which enables coordinator if it was requested
from settings, but it should be done only for non-initial queries, i.e.
when server send connection to another server.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
* Fix 02226_parallel_reading_from_replicas_benchmark for older shellcheck
By shellcheck 0.8 does not complains, while on CI shellcheck 0.7.0 and
it does complains [1]:
In 02226_parallel_reading_from_replicas_benchmark.sh line 17:
--allow_experimental_parallel_reading_from_replicas=1
^-- SC2191: The = here is literal. To assign by index, use ( [index]=value ) with no spaces. To keep as literal, quote it.
Did you mean:
"--allow_experimental_parallel_reading_from_replicas=1"
[1]: https://s3.amazonaws.com/clickhouse-test-reports/34751/d883af711822faf294c876b017cbf745b1cda1b3/style_check__actions_/shellcheck_output.txt
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
