MXS-1282. The flags "-g=arglist" or "--debug=arglist" activate
the debug settings specified in the comma-separated list arglist.
Currently, the setting "disable-module-unloading", which prevents
modules (.so-files) from being unloaded at exit, is supported. This
allows Valgrind to produce line numbers for leak reports when the
memory was allocated in a module. The setting "enable-module-unloading"
is also available, but this is activated by default.
The debug arguments and their actions are defined in a structure
array, so adding more is straightforward.
The /users/ resource shows all user accounts that can be used with
MaxScale. This resource is further split into two resource collections,
/users/inet and /users/unix, which contain the network users and Linux
accounts respectively.
When MaxScale is started, a separate thread for the administrative
interface is started. This allows the worker threads to handle client
requests while the administrative thread handles the lower priority
administrative requests.
The administrative interface responds to all request with a 200 OK HTTP
response. This allows the administrative interface itself to be tested.
The shutdown is now performed so that a shutdown message is
sent to all workers. When the workers receive that message, they
turn on a shutdown flag, which subsequently is checked in the poll
loop.
MXS_WORKER is an abstraction of a worker aka worker thread.
It has a pipe whose read descriptor is added to the worker/thread
specific poll set and a write descriptor used for sending messages
to the worker.
The worker exposes a function mxs_worker_post_message using which
messages can be sent to the worker. These messages can be sent from
any thread but will be delivered on the thread dedicated for the
worker.
To illustrate how it works, maxadmin has been provided with a new
command "ping workers" that sends a message to every worker, which
then logs a message to the log.
Additional refactoring are needed, since there currently are overlaps
and undesirable interactions between the poll mechanism, the thread
mechanism and the worker mechanism.
This is visible currently, for instance, by it not being possible to
shut down MaxScale. The reason is that the workers should be shut down
first, then the poll mechanism and finally the threads. The shutdown
need to be arranged so that a shutdown message is sent to the workers
who then cause the polling loop to exit, which will cause the threads
to exit.
That can be arranged cleanly by making poll_waitevents() a "method"
of the worker, which implies that the poll set becomes a "member
variable" of the worker.
To be continued.
The connector plugin directory can now be controlled with the
`connector_plugindir` argument and configuration option. This should allow
the connector to use the system plugins if the versions are binary
compatible.
Replaced calls to mysql_options to mysql_optionsv as the former is
deprecated in Connector-C 3.0 and the latter is supported in Connector-C
2.3.
When MaxScale is started, it will attempt to create the PID directory. If
the directory does not exist and MaxScale is able to create it, MaxScale
will successfully start whereas it previously failed to do so.
If MaxScale lacks the permissions to create the directory, an error
message is printed to the user explaining the reason why MaxScale fails to
start.
The random number generator can be initialized when MaxScale's other
systems are being initialized. This removes the need to initialized it
when the function is used for the first time.
This header defines some general functions and maxscale main() return
values. Most of it is still public, but there were some functions
which were moved to a core header.
Moved some typedefs to router.h and server.h, changed a few
constants to these enums. Renamed some types in config.h to
remove "Gateway".
There are still some functions in the public header which are
only used in core, but they seem to fit the theme of public functions
so were not moved.
The external config.h header defined functions and structures that are
intended to be used by modules. The internal header contains functions
that are used only by the MaxScale core.
This directory is intended to be the default working directory for
relative pathname resolution. The actual implementation for
MXS_MODULE_PARAM_PATH is done at a later step.
The setting up and the initialization of the query classifier has
now been separated. The gateway explicitly sets up the query
classifier (i.e. chooses which one to use and what arguments to
provide), but the actual initialization is performed as part of
the general module initialization.
