stracktrace:
...
2 DB::WriteBuffer::nextIfAtEnd (this=0x0) at ../dbms/src/IO/WriteBuffer.h:66
3 DB::writeVarUInt (ostr=..., x=3) at ../dbms/src/IO/VarInt.h:191
4 DB::Connection::sendCancel (this=0x7f0b7f5e5610) at ../dbms/src/Client/Connection.cpp:444
5 0x0000561738d0b565 in DB::MultiplexedConnections::sendCancel (this=0x7f0c9b0173e0) at ../dbms/src/Client/MultiplexedConnections.cpp:174
6 0x00005617387d22df in DB::RemoteBlockInputStream::tryCancel (this=0x7f0cc45f9810, reason=<optimized out>) at /usr/include/c++/9/bits/unique_ptr.h:352
7 0x00005617387d2a37 in DB::RemoteBlockInputStream::cancel (this=<optimized out>, kill=false) at ../dbms/src/DataStreams/RemoteBlockInputStream.cpp:121
8 0x000056173891f10c in DB::ParallelInputsProcessor<DB::UnionBlockInputStream::Handler>::cancel (this=0x7f0c370ec168, kill=kill@entry=false)
9 0x000056173892cfce in DB::UnionBlockInputStream::cancel (kill=false, this=<optimized out>) at ../dbms/src/DataStreams/UnionBlockInputStream.h:99
10 DB::UnionBlockInputStream::Handler::onException (this=0x7f0c370ec160, exception=...) at ../dbms/src/DataStreams/UnionBlockInputStream.h:240
11 DB::ParallelInputsProcessor<DB::UnionBlockInputStream::Handler>::thread (this=0x7f0c370ec168, thread_group=..., thread_num=<optimized out>)
at ../dbms/src/DataStreams/ParallelInputsProcessor.h:217
And in onException frame there is:
(gdb) p ((DB::Exception *)exception._M_exception_object)._msg._M_dataplus._M_p
$6 = (...) 0x7f0c9b1e7a40 "Unknown packet 9 from server HOSTNAME:PORT"
And on "Unknown packet" there is disconnect() before, see default in
switch statement at Connection::receivePacket().
