The monitor timeouts can now be larger than the monitor interval. This will
allow the combination of low monitoring intervals and large network timeouts.
If a network experiences some periodic lag, it is desirable to allow large
timeout values.
The real username and host is now logged in addition to the user definition
that it matched. The messages also have the service name to distinct
connections to two different services which both use the same filter.
If transaction safety was disabled and a large event sent in multiple SQL
packets was received, the distribution of that event to the slaves would fail.
The empty packet sent after a large event which fits into exactly one packet
was written to disk and the writing of no bytes caused it to be treated as
an error.
The router->last_written is used to store the position where the last event was
written. The replication header is also stored in a separate structure in
the router which is used later when the last packet of a multi-packet event
arrives.
The number of written characters is now checked and should be lower than
compared bytes. The parameters to the dbusers.c query functions are now const
where possible.
Previously the users needed at least SELECT permission on the database level to
be able to connect with a default database through MaxScale. With this change,
the query that retrieves the database users has been changed to also include
table-level grants for users. This will allow users with grants to only some of
the tables in a database to be able to connect through MaxScale with a default
database.
The queries are now created at runtime to allow for a more varied syntax. This
removes the need to have separate query strings for the standard mysql.user
table and for the MySQL 5.7 version of it. In addition to this, the exclusion
of the root user is now done at the same time which removes the need to manually
form the query string.
The admin users are now encrypted with a more complex algorithm which reduces
the chance of two passwords generating the same hash by a significant amount.
Refer to the GNU libc manual for more details about the crypt function:
http://www.gnu.org/software/libc/manual/html_node/crypt.html
The checking of the master status and the possible error logging were done
in two different steps. This led to confusing error messages when the state
of the server changed between the check and the logging of the error message.
Systems that support systemd only use the systemd service files. For other
systems, System V style init scripts are installed. It is not recommended to
install both of them since it's possible that they will perform differently.
When a module is unregistered, it must be removed from the list.
Otherwise, if explicit unregistering of a module is made, there
will be a crash at shutdown when all modules are unregistered.
For external parsing there will be a separate process that handles
parse requests sent from MaxScale. From MaxScale's perspective there
will just be a specific query classifier plugin that upon startup
launches that external process and manages its lifetime. That is,
MaxScale proper will be completely oblivious of this arrangement.
The skeleton process introduced here does nothing; just sits in
a loop sleeping. The skeleton query classifier plugin currently
loads the MySQL embedded query classifier and performs parsing
using it. That way the external process based query classifier can
immediately be used.
Next step is to introduce process management into the picture without
actually moving the parsing anywhere.
Not finished yet. There are e.g. a number of functions that are only used
by the log manager. They could just as well be moved as private functions
to log_manager.cc.
