Before the MXS-2250 fix, the following ends with an error:
CREATE TEMPORARY TABLE t (f INT);
DESCRIBE t;
Reason is that the first is sent to the master (and the table will
not be replicated to slaves) and the latter to some slave.
When a statement like 'DESCRIBE tbl' is classified, the table
name will now be available so that a router can check whether the
table is a temporary one. In that case, the statement must be sent
to the master.
The command script is now stored in string form. Substitution is performed
using normal string methods instead of regular expressions, since all used
substitutions are simple string replacements. Tokenization is performed after
substitution.
By iterating over the servers and sending the master's charset we are
guaranteed a "known good" charset. This also solves the problem where a
deactivated server reference would be used as the charset and server
version source.
If the execution of a session command fails on a master, it is retried
again. If the master is not available, the response will be returned from
one of the slaves.
The retrying of a read on a slave should only be done when the failing
server is waiting for a result and it was the last server from which a
result was expected.
If the master fails when a session command is being executed with
delayed_retry enabled, a null query would get placed into the query
queue. This change simply prevents the crash and closes the session even
though the query could be retried.
The bug appears when a session command that is executed on the master
fails. The logic in the code doesn't take this case into consideration
when it processes failed connections.
A query should not be queued if no responses are expected. The code that
executes queued queries should be dead code and this assertion would catch
it.
Older clients assume the plugin used for authentication is
mysql_native_password. If the client doesn't request plugin
authentication, don't treat it as an error.
The tests now check that multiple parameters work as expected. Also fixed
a few defects found while writing the tests, namely the fact that null or
empty values weren't detected.
Multiple parameters can now be updated with a single call in MaxCtrl. This
makes alterations more convenient and prevents intermediate states when
multiple parameters are changed at the same time. The changes are
backwards compatible so it should not affect existing programs.