The error was only generated for COM_STMT_EXECUTE commands when all PS
commands should trigger it. In addition, large packets would get sent two
errors upon the arrival of the trailing end.
Syncing the slaves should prevent replication lag from affecting the
test. The added logging will help determine what the error was that caused
the failure.
If an error is generated while a COM_CHANGE_USER is being done, it would
always use the sequence number 1. To properly handle this case and send
the correct sequence number, the COM_CHANGE_USER progress needs to be
tracked at the session level.
The information needs to be shared between the backend and client
protocols as the final OK to the COM_CHANGE_USER, with the sequence number
3, is the one that the backend server returns. Only after this response
has been received and routed to the client can the COM_CHANGE_USER
processing stop.
If a server fails mid-resultset, there's not a lot we can do to recover
the situation. A few cases could be handled (e.g. generate an ERR if the
resultset has proceeded to the row processing stage) but these fall
outside the scope of the original issue.
As is explained in MDEV-19893:
Client reads from socket, gets the packet from 1. with seqno=0, which
it does not expect, since seqno is supposed to be incremented. Client
complains, throws tantrums and exceptions.
To cater for clients that do not expect out-of-bound messages
(i.e. server-initiated packets with seqno 0), all messages generated by
MaxScale should use at least sequence number 1.
Deep-copying prevents subsequent modifications done by the caller from
affecting the data that can be potentially stored in the write queue of
the backend's DCB.
It was possible that a one-second outage that caused immediate rejection
of network connections would cause all of the query retry attempts to fail
within a very short period of time. By preventing rapid reconnections,
query_retries is more effective as an error filtering mechanism.
In Ubuntu Bionic there is need to update libssl which causes system services restart
and apt asks user to allow this restart. It cases build script to hang and build fails due to timeout.
Additional dpkg options and DEBIAN_FRONTEND=noninteractive solves the problem
If a COM_STMT_EXECUTE has no metadata in it and it has more than one
parameter, it must be routed to the same backend where the previous
COM_STMT_EXECUTE with the same ID was routed to. This prevents MDEV-19811
that is triggered by MaxScale routing the queries to different backends.
The directory was installed as the root user but later on in the
installation process the owner would be changed to the maxscale user. This
causes some validation programs to fail as they expect installed files to
retain the original ownership.
mxs::Buffer::iterator is not a random-access iterator and hence will have
linear cost. This is too costly to do on every packet with even moderately
sized resultsets.
Due to there being no distinction between a temporarily stopped worker and
a permanently stopped one, we must allow posting of messages to stopped
workers.
By always restoring the ID, we are guaranteed to only store the query in
the form that it was originally sent in. This should be changed so that
the ID that the client sends can be used as-is in the backends.
By having a separate FINISHED state and a STOPPED state, it is possible to
know at which point in the worker's lifetime an event is done. Posting of
messages before a worker is started is allowed but posting them after the
worker has stopped is not.
This fixes avrorouter related failures and all other failures that stem
from worker messages being ignored at startup.
By stopping the REST API before the workers and moving the shutdown to the
same worker that handles REST API requests, we prevent the hang on
shutdown. This also makes the signal handler signal-safe.
