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.
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.
If a worker has been stopped, tasks must not be executed on it. To prevent
this, the calling code should check whether the worker has been
stopped. This does not prevent the case where a message is successfully
posted to a worker but the worker is stopped before it processes it.
The slave connection I/O-tread stays running if replication credentials are
wrong when connecting to master. This causes a switchover/failover timeout.
When this happens, print the error in the slave connection status as this
clarifies the problem to the user.
If one slave is executing a query while another one is executing a session
command and the one that is executing the session command fails, the
ongoing query would get retried even though the server that failed was not
executing it. If the server was executing a session command, nothing needs
to be done.
RWBackend did not expect that a resultset and an unexpected ERR packet
could be stored in the same buffer. This can happen for example if a
server shuts down immediately after the resultset is sent.
