The lack of user definition lines in the dbfwfilter rule file was ignored
previously but this change makes the lack of users an error again. Also
added function documentation to some of the functions.
The real username and host is now logged in addition to the user definition
that it matched. The messages also have the service name to distinct
connections to two different services which both use the same filter.
If transaction safety was disabled and a large event sent in multiple SQL
packets was received, the distribution of that event to the slaves would fail.
The empty packet sent after a large event which fits into exactly one packet
was written to disk and the writing of no bytes caused it to be treated as
an error.
The router->last_written is used to store the position where the last event was
written. The replication header is also stored in a separate structure in
the router which is used later when the last packet of a multi-packet event
arrives.
The checking of the master status and the possible error logging were done
in two different steps. This led to confusing error messages when the state
of the server changed between the check and the logging of the error message.
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.
When a command that changes the session state is executed on all servers and
a slave server goes down, an error message was sent to the client even though
one wasn't expected. These appeared as odd connection errors on the client side.
When a query is being routed to the slave, it is not necessary to assert that
the master server's state is still master. It is possible that the master server
changes states while the query is being routed but that doesn't affect the query
being currently routed.
The master DCB was checked for NULL-ness but the proper way is to check if
the backend reference is closed. This will fix a debug assertion in addition
to possibly preventing crashes.
When the shard maps are being updated they are set into a stale state. This
means that one client connection is updating the shard maps and the information
in the shard map is not the most recent. This does mean that the information
is valid and authentication should succeed even if the shard map is stale.
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.
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.
When a slave server fails to execute a session command, the log message printed
the command that was being executed as if the ERR packet was a COM_QUERY packet.
This caused corrupt strings to be printed into the error logs.
In blr_slave_callback the bits of slave->cstate are reset and
set as one transaction. Earlier they were reset in one and
set in another, leading to a situation where slave->cstate did
not contain a sensible value for a short period of time.
Further, it is now explicitly checked in blr_distribute_binlog_record
that slave->cstate indeed contains a meaningful value.
A debug assertion in the readwritesplit would always fail when the master DCB
was NULL. This was caused by the fact that the debug assertion assumes that the
pointer that is passed to it is a valid pointer.
