For external parsing there will be a separate process that handles
parse requests sent from MaxScale. From MaxScale's perspective there
will just be a specific query classifier plugin that upon startup
launches that external process and manages its lifetime. That is,
MaxScale proper will be completely oblivious of this arrangement.
The skeleton process introduced here does nothing; just sits in
a loop sleeping. The skeleton query classifier plugin currently
loads the MySQL embedded query classifier and performs parsing
using it. That way the external process based query classifier can
immediately be used.
Next step is to introduce process management into the picture without
actually moving the parsing anywhere.
Not finished yet. There are e.g. a number of functions that are only used
by the log manager. They could just as well be moved as private functions
to log_manager.cc.
Slist removed from skygw_utils and added as a separate component.
Nobody seems to be using it, so it could also simply be removed.
Left in place for the time being.
Shutting down monitors is not supposed to be done ofter so there is no true
benefit from keeping the connections open. With the refactoring of the monitor
interface, this can be done in a centralized place.
The dbfwfilter now uses flex to tokenize the rules and bison to process those
tokens into a language. This will make the syntax checks more robust and
the rule language easier to maintain. It also makes the processing of rules
easier to understand and removes most of the C language side checks for
correctness.
The old rule processing functions are still left intact and will be removed
at a later point.
When configured to log matching queries, the dbfwfilter will log all queries
that match a rule. The rule name, user name and the query itself are logged.
It is also possible to match all queries that do not match a rule. Only the user
name and query is logged in this mode.
The check for the server status explicitly denied servers that are both master
and slave from being chosed as candidates for queries. This is only a problem
when a user manually sets the server states to both master and slave.
The monitors resolve the replication topology based on the servers that
the monitors see and this always results in at least one slave server.
The FindMariaDBConnector.cmake file now checks if the found library actually is
the MariaDB Connector-C library. If the found library is not the MariaDB
Connector-C, it will be built from source.
The include directories previously used by MaxScale were from the embedded
library. All parts of MaxScale apart from the query classifier now use
the client libraries.
Since maxscale-common is linked to the connector-c library
and no longer to the MySql embedded library, mysql_library_init
does not need any parameters.
There can be any sort of library behind qc_init. Hence the arguments
cannot be hardwired to be like the embedded library wants them.
Eventually it might make sense to allow passing arguments from
maxscale.cnf.
Now, qc_mysqlembedded is linked against MySQL's embedded library,
and MaxScale itself against Connector-C.
So, in order to build MaxScale, Connector-C must be installed.
This has been tested with Connector-C 2.2.1.
The build variable MYSQLCLIENT_LIBRARIES is no longer used.
The query_classifier library is now only a wrapper that loads an
actual query classifier implementation. Currently it is hardwired
to load qc_mysqlembedded, which implements the query classifier
API using MySQL embedded.
This will be changed, so that the library to load is specified
when qc_init() is called. That will then allow the query classifier
to be specified in the config file.
Currently there seems to be a conflict between the mysql_library_end()
call made in qc_mysqlembedded and the mysql_library_end() call made in
gateway.c. The reason is that they both finalize a shared library.
For the time being mysql_library_end() is not called in gateway.c.
This problem is likely to go away by switching from the client
library to the connector-c library.
Now, qc_mysqlembedded is linked against MySQL's embedded library,
and MaxScale itself against Connector-C.
So, in order to build MaxScale, Connector-C must be installed.
This has been tested with Connector-C 2.2.1.
The build variable MYSQLCLIENT_LIBRARIES is no longer used.
The query_classifier library is now only a wrapper that loads an
actual query classifier implementation. Currently it is hardwired
to load qc_mysqlembedded, which implements the query classifier
API using MySQL embedded.
This will be changed, so that the library to load is specified
when qc_init() is called. That will then allow the query classifier
to be specified in the config file.
Currently there seems to be a conflict between the mysql_library_end()
call made in qc_mysqlembedded and the mysql_library_end() call made in
gateway.c. The reason is that they both finalize a shared library.
For the time being mysql_library_end() is not called in gateway.c.
This problem is likely to go away by switching from the client
library to the connector-c library.
Earlier the same (or almost the same) code was duplicated in
several places.
A conflicting declaration was also removed. There was no
implementation for that declaration.
If a password is gived as an argument, that password is shown to other users.
Changed it so that the password is copied locally and the argument cleared.
The polling statistics collection used atomic_add to increment values. This
is not an optimal way to update statistical values. Moved to per thread
values which are summed up when they are read.
Moved the functions used to gather polling statistics to their own file and
created a specific data type for statistics.
Currently not used, but the existing query_classifier will be
changed into being just a wrapper around a dynamically loaded
query classifier plugin, i.e. qc_mysqlembedded.
Added a query classifier plugin interface using which plugins
export their functionality. Cleaned up header slightly as well.
This is the first step in the process of making the loading of
the query classifier truly dynamic.
The THREAD type was not used everywhere and pthread_t was used instead.
The thread creation function also returned the address of a stack allocated
value which isn't guaranteed to be usable.
Only the query classifier needs the functionality of the embedded
server, while the rest of MaxScale is content with the client
library or Connector/C.
This have now been rearranged so that query-classifier links with
the embedded static library and then explicitly exports its own
functions using the query_classifier.map linker script. That way
query classifier will use the embedded library, while the rest of
maxscale use the client library, and this without conflicts.
Currently, query_classifier is not linked to maxscale-common,
but executables must link to maxscale-common and query_classifier.
Earlier thread initialization was done in poll_waitevents(),
which was somewhat confusing, since the main thread also calls
into poll_waitevents().
Now there is a specific thread "main" function, which first
performs thread specific initialization and then calls into
poll_waitevents().
Platform.h is intended to contain definitions and workarounds
for concepts that depend upon the used compiler and/or platform.
Currently it ensures that /thread_local/ is available irrespective
of whether the source is compiled in pre- or post C11 or C++11 mode.
This file should be included first by all MaxScale headers.
