The monitor now continuously updates a list of enabled server events. When
promoting a new master in failover/switchover, only events that were enabled
on the previous master are enabled on the new. This avoids enabling events
that may have been disabled on the master yet stayed in the SLAVESIDE_DISABLED-
state on the slave.
In the case of reset-replication command, events on the new master are only
enabled if the monitor had a master when the command was launched. Otherwise
all events remain disabled.
Worker::STOPPED -> MONITOR_STATE_STOPPED
Worker::POLLING -> MONITOR_STATE_RUNNING
Worker::PROCESSING -> MONITOR_STATE_RUNNING
By defining the monitor state from the worker state there is
no risk they will ever get out of sync. And there is one thing
less to maintain.
The manipulation functions are currently static so that the container can be initialized
if required. This will be fixed later.
The new functions are taken into use in monitor management.
Since the settings are now protected fields, all related functions were
moved inside the monitor class. mon_ping_or_connect_to_db() is now a method
of MXS_MONITORED_SERVER. The connection settings class is defined inside the
server since that is the class actually using the settings.
The setting didn't work because the code updated a status flag which
would be overwritten before being read. Also, promotion code now checks
that the server is not in maintenance.
Now logs messages explaining what has been done. Scheduled events are
disabled/enabled during the operation. Redirection of slaves is done at
the end similar to failover/switchover.
The 'reset_replication' module command deletes all slave connections and binlogs,
sets gtid to sequence 0 and restarts replication from the given master. Should be
only used if gtid:s are incompatible but the actual data is known to be in sync.
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.
See script directory for method. The script to run in the top level
MaxScale directory is called maxscale-uncrustify.sh, which uses
another script, list-src, from the same directory (so you need to set
your PATH). The uncrustify version was 0.66.
No longer depends on monitor events as the other operations do not
either. The active_event/new_event detection was removed, as these
only protect against a rare situation. A similar feature which
protects all the cluster modifications will be implemented later.
When the replication status from the external master is checked, the
pending status must be used. This makes sure that the SlaveStatusArray and
the server state are sync.
Also extended the message that was logged when the external master was
lost. By adding the network address there, it makes it easier to see where
the server was replicating from if only the log file is available.
