In case of ECONNRESET (Connection reset by peer) the "cancelled" will
not be set, and so drain() will fail with LOGICAL_ERROR:
<details>
2021.10.16 04:10:55.054771 [ 7635 ] {882164e0-ca26-4955-8759-708ba1f6e85c} <Error> PullingAsyncPipelineExecutor: Code: 210. DB::NetException: Connection reset by peer, while writing to socket (127.0.0.2:9000). (NETWORK_ERROR), Stack trace (when copying this message, always include the lines below):
...
4. ./obj-x86_64-linux-gnu/../src/Common/NetException.h:12: DB::NetException::NetException(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, int) @ 0x20db5749 in /usr/bin/clickhouse
5. ./obj-x86_64-linux-gnu/../src/IO/WriteBufferFromPocoSocket.cpp:56: DB::WriteBufferFromPocoSocket::nextImpl() @ 0x211d56bb in /usr/bin/clickhouse
6. ./obj-x86_64-linux-gnu/../src/IO/WriteBuffer.h:47: DB::WriteBuffer::next() @ 0x14e4c874 in /usr/bin/clickhouse
7. ./obj-x86_64-linux-gnu/../src/Client/Connection.cpp:560: DB::Connection::sendCancel() @ 0x227c0c22 in /usr/bin/clickhouse
8. ./obj-x86_64-linux-gnu/../src/Client/HedgedConnections.cpp:242: DB::HedgedConnections::sendCancel() @ 0x227f1b53 in /usr/bin/clickhouse
...
2021.10.16 04:12:35.555530 [ 5575 ] {} <Fatal> : Logical error: 'Cannot drain connections: cancel first.'.
</details>
Found by stress tests on CI [1].
[1]: https://clickhouse-test-reports.s3.yandex.net/0/d3cb99701d4aaec384fd183168d10e0f650ecc1d/stress_test_(debug).html#fail1
In case only one block in the query execution, LocalConnection can
return Progress packet instead of the block itself, after it will call
poll() again and the block will got lost.
Fix this by processing block before Progress packet.
And actually AFAICS Progress can be removed after pollImpl(), since
there is Progress handling before.
Fixes: #30282 (cc @kssenii)
This can be useful for debugging and for testing (since you will not
need to obtain query_id and look at query_log).
v2:
- mark test as long
- add option to docs
- add type of profile event into logs too
v3:
- resolve conflicts
- and fix onProfileEvents callback
v4:
- add --print-profile-events separate switch
