Since the module command interface was expanded to include a JSON output
parameter, there is no longer a need for an output DCB. As the JSON can be
printed by both maxadmin and the REST API, this allows the removal of
explicit output formatting in module commands.
The `failover` and `failover_timeout` parameters are now declared as a
part of the mysqlmon module. Changed the implementation of the failover
function so that the dependencies on the monitor struct can be removed or
moved into parameters.
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.
As the monitor event is now stored in the server, it can be re-used when
the event is converted to string form. This also fixes the problem of
state calculation taking place when the event happened in the past.
The failover command is simulated by executing a call to /usr/bin/echo
with all possible monitor parameters. This allows testing of the failover
mechanism without actually using the failover command.
The timestamp of the last change from passive to active is now
tracked. This, with the timestamps of the last master_down and master_up
events, allows detection of cases when MaxScale was failed over but the
failover was not done.
Currently, only a warning is logged if no new master has appeared within
90 seconds of a master_down event and MaxScale was set to active from
passive.
The last event and when the event was triggered is now shown for all
servers. The latest change from passive to active is also shown.
When an event occurs on a server, it is now stored so that the last event
for each server is known. This allows a state change to trigger an event
even if, at the time of the event, no action was taken.
This change is only cosmetic as no functionality is implemented.
The `passive` parameter can be given in the configuration file or on the
command line. It is displayed in the diagnostic output and changes to it
are persisted.
The variable itself does nothing.
The `script_timeout` and `journal_max_age` parameters weren't handled in
the monitor alteration code.
Also added missing documentation to maxadmin help output for
`alter monitor`.
If a script variable resolves to an empty string, the replacement attempt
will fail with an out-of-memory error. The following realloc call will
fail as it requires a positive value for the new size.
If an invoked script must access servers, it needs credentials.
When invoked, a script can now be provided with the monitor
credentials of MaxScale using the variable CREDENTIALS.
It will be expanded like
user:password@[...]:N1,user:password@[...]:N2
for every server the monitor in question is monitoring. That is,
irrespective of whether it is a master or a slave, running or not.
Thus, a failover script could be specified like:
[MyMonitor]
type=monitor
module=mysqlmon
...
script=.../failover.sh --credentials=$CREDENTIALS --slaves=$SLAVELIST
events=master_down
Note, it may make sense to introduce specific failover (and switchover)
keywords, but with the above addition it is possible to start
experimenting with failover scripts.
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.
When the subprocess outputs a line, the message should be logged
immediately. This allows automated timestamps for the output of the
executed subprocess.
By moving the initialization into Worker::run, all threads, including the
main thread, are properly initialized. This was not noticed before as
qc_sqlite initialized the main thread in the process initialization
callback.
The enums exposed by the connector are not intended to be used by the
users of the library. The fact that the protocol, and other, modules used
it was in violation of how the library is intended to be used.
Adding an internal mapping into MaxScale also removes some of the
dependencies that the core has on the connector.
Cleaned up the MaxScale version of the mysql.h header by removing all
unused includes. This revealed a large amount of dependencies on these
removed includes in other files which needed to be fixed.
Also sorted all includes in changed files by type and alphabetical
order. Removed explicit revision history from modified files.
Basically it would be trivial to report far more operations
explicitly, but for the fact that the values in qc_query_op_t
currently, quite unnecessarily, form a bitmask.
In 2.2 that is no longer the case, so other operations will be
added there.
Apart from listeners, all DCBs will be assigned to the current
thread. This simplifies the addition of DCBs to worker threads.
Also performed a small cleanup of poll_add_dcb to make it more readable.
Thread-local non-POD types are not supported on CentOS 6 and thus they
need to be replaced with pointers to the relevant objects and initialized
at runtime.
In addition to this, functor objects don't appear to work as expected in
CentOS 6 and replacing them with a simple for-loop seems to work.
