Previously, if the server had no gtid:s, the method would fail leading to
a confusing error message. This could even totally stop the monitor from working
if a recent server version (10.X) did not have any gtid events.
The main class was getting unwieldly and too general. Dividing the fields
helps adding support for other operation types.
This commit leaves most data duplicated, later commits clean up the affected code.
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.
The redirection method checks if a slave connection to the redirection
target already exists. If so, the connection is not modified. Also, failover
better detects duplicate connections during promotion.
The removing and slave status updating is now separated to a function.
As the MariaDBServer object now contains the updated slave connections,
keeping track of removed connections is no longer required.
The two cases are now separated. In switchover, the promotion and
demotion targets can swap connections between each other without worry.
In failover, the two connection lists must be merged semi-intelligently.
The slave connections of the two servers are now saved to the operation
descriptor object at the start of the operation. This allows slave status
updating during the operation.
Several small changes:
Binlog is flushed at the end of old master demotion.
Only new master is required to catch up to old master.
Use the same replication check method as failover.
No longer writes events to the master, as this creates problems if the
promoted server was not the overall master. Instead, the slave status
output is inspected.
Clean up, comments and enhancements. StopWatch lap() didn't mean lap-time, but elapsed time. Changed meaning to lap-time and added split() for split-time.
In progress, does not yet overwrite existing code.
The new promotion mechanism automatically retries queries which timed out. It also
handles multimaster situations correctly.
The test adds a scheduled server event, the does failover, rejoin and
switchover and checks that event is manipulated correctly. Also includes
a change to the monitor to fix an invalid ALTER EVENT query when the event
definer has wildcard host.
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.
Since the servers are not modified before or during the wait, the waiting
can be done in the preparation method. This simplifies the actual failover
somewhat, and allows the monitor to keep running normally while waiting for
the log to clear.
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.
