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.
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.
This is the first change in an attempt to arrange the linking so that
more errors are detected at link-time.
- All files in server/core but for gateway.c are linked to one shared
library called maxscale-common.
- The files log_manager/log_manager.cc and utils/skygw_utils.cc are
built into maxscale-common as well.
- MaxScale itself consists now only of gateway.c and is linked with
maxscale-common.
- All plugins link with maxscale-common.
- All executables link in addition with {EMBEDDED_LIB}.
After this change, the change (MXS-517) where query_classifier is the
only component that uses ${EMBEDDED_LIB} and the rest mysqlclient can
be made much cleaner.
After a few additional steps, all shared libraries can be linked with
the linker flags "-Wl,-z,defs", which directs the linker to resolve
all symbols. That will require that all shared libraries list all the
libraries they need, but will at the same time ensure that any
missing symbols are detected at link-time and not at run-time.
The preparation and closing of prepared statements was sent to all servers
even though the execution was always sent to the master. With this change,
all queries which interact with prepared statements are only sent to the master.
The sending of statement preparations to all servers is a problem when a
statement which depends on a database or a table is created and the DDL
statement which created that table has not yet been replicated to the
slaves.
In addition to fixing the aforementioned problem, this change should also
reduce unnecessary network traffic to slaves and improve the overall
performance of the prepared statements.
When MaxScale perceives a state change in one of the servers it will log
an message into the log file stating the previous and the current state.
This will make it easier to analyze failures in the cluster.
Changed burst_size to long instead of unsigned long.
This way check burst_size > 0 is now effective.
Setting "burstsize" option in router_options may be required.
i.e.: burstsize=10M
Changed burst_size to long instead of unsigned long.
This way check burst_size > 0 is now effective.
Setting "burstsize" option in router_options may be required.
i.e.: burstsize=10M
It was possible that a backend server was doing authentication while the client
closed the session. The more connections the router created the more likely it
was. This caused unnecessary reloading of the database users and confusing error
messages.
With the implemented fix, there are additional checks for the session state
before the users are reloaded or error messages are logged.
Since the PCRE2 library was always going to be a part of MaxScale, there was
no real reason to have it as a shared library apart from smaller binaries.
The username matching was working as intended but the session's active value
was ignored when queries were being routed. This meant that both the username
and the IP address of the user were ignored and query replacement was always
done.
The binlog file is now always opened when it is needed and closed
when we are finished with it. That will remove any potential
file concurrency issues between different threads dealing with
the same slave.
The binlog file is now always opened when it is needed and closed
when we are finished with it. That will remove any potential
file concurrency issues between different threads dealing with
the same slave.
Slave request for a log_pos behind binlog file size may result in a
disconnection or replication error:
if binlog file is latest one slave get disconnected otherwise an error
message is returned and replication stops
Slave request for a log_pos behind binlog file size may result in a
disconnection or replication error:
if binlog file is latest one slave get disconnected otherwise an error
message is returned and replication stops
Made some variables stack allocated so there is no change of memory leaking.
There was no real reason to allocate memory from the heap for the variables in
question since they did not need to persist outside the scope of the function.
