Event handling is now enabled by default. If the monitor cannot query the EVENTS-
table (most likely because of missing credentials), print an error suggesting to
turn the feature off.
When disabling events on a rejoining standalone server (likely a former master),
disable binlog event recording for the session. This prevents the ALTER EVENT
queries from generating binlog events.
Also added documentation and combined similar parts in the code.
The auto_failover is a more reliable solution and should be used instead. Several
unused parameters were removed, although they can still be defined in the config
file. Updated documentation on the relevant parts.
The disk configuration can be different on different servers.
Hence it should be possible to specify the disk space threshold
separately for each server.
If the feature is enabled (default off), at the end of a monitor loop
(once server states are known), read_only is enabled on slaves servers
without it.
In this case, the server was already a slave and is not being demoted. Also, the file may
contain queries which cannot be ran while a slave connection is running.
For some reason, the source code of mysqlmon was split into C and C++
sources. This caused problems by effectively discarding all changes from
2.1 that are merged into 2.2.
This commit merges the changes into the correct file that were added to
the wrong file.
The new parameter allows ignoring of master servers that are external to
the monitor configuration. This allows sub-trees of the actual replication
tree to be used as fully fledged replication trees.
The master failure can now be verified by checking when the slaves are
connected to the master. If the slaves do not receive any events from the
master, the connections are considered as down after a configurable limit.
Added two parameters for controlling whether the check is done and for how
long the monitor waits before doing the failover.
If a switchover_script parameter is given, its value will be used as
the switchover script. Otherwise the default will be used. Currently
just echo.
The MySQL Monitor now introduces two script variables, CURRENT_MASTER
and NEW_MASTER, that contain information about the current and new
master respectively.
Switchover is performed only if switchover has been enabled and MaxScale
is *not* in passive mode.
Tentative documentation.
With the 'switchover' config variable the switchover functionality
can be enabled. If enabled a REST API endpoint will appear, using
which that switchover can be initiated.
Switchover can only be performed when MaxScale is in active mode
and failover will be disabled for the duration of the switchover.
Only if the switchover succeeds, will failover be enabled again.
Might be easier to expose that REST API always and only change
the behaviour when calling it, instead of making it appear and
re-appear.
Split the state change processing and failover handling into two separate
functions and added a call to the failover function into mysqlmon. This
prevents unintended behavior when failover is enabled for non-mysqlmon
monitors. The parameter itself still needs to be moved into mysqlmon.
Moved the failover documentation to the mysqlmon documentation as it is
specific to this monitor.
The CHILDREN parameter expands to a list of server IPs and ports that are
direct descendants of the server that initiated the event.
Also added a note that the variables can expand to empty strings if
nothing matches the criteria of the variable.
The scripts now replace the PARENT variable with the IP and port of the
server that is the direct parent node of the server that initiated the
event. For master-slave clusters, this will be the master IP if the server
that triggered the event is a slave.
If the executed subprocess prefixes its output with either `error:`,
`warning:` or `info:`, the message will be logged on the appropriate
level. If no prefix is provided, the message is logged on the notice
level.
