The readwritesplit now sends COM_PING queries to backend servers that have
been idle for too long. The option is configured with the
`connection_keepalive` parameter.
The contents of the existing filter.cc was copied into filter.c that
subsequently was renamed to filter.cc.
The way the session is called as the last filter in the filter chain
is really dubious and ought to be rearranged so that the blind casting
of a session to a filter and back is not needed.
It is now possible to specify what information the caller is interested
in. With this the cost for collecting information during the query parsing
that nobody is interested in can be avoided.
The match data needs to be unique for each thread, so for the time
being it is created whenever it is needed. A more performant (although
possibly to a negigible amount) solution would be to have a separate
match data for each thread, but that will have to wait for 2.2.
- Non-GCC intrinsics alternative implementation removed. Let's worry
about the absence of the intrinsics once/if that becomes relevant.
- Spinlock release now performed using __sync_lock_release, as per
svoj's advice.
- while-looping on the variable used as lock removed, so it no longer
need to be volatile.
- Boolean function returns bool.
- Size of profiling counters increased.
- Risk for division-by-zero removed.
- Documentation moved from implementation to header.
When MaxScale is being started and the users are loaded, the MySQL
authenticator should not load the database users for internal services
abstracted as servers.
The loading of users at startup for internal services is avoided because
the startup is done in a single thread context and the internal services
have not yet been started.
The delayed loading of users will cause the authentication to fail when
the first client connect. This triggers the reloading of the users and the
second attempt at authentication will succeed. All of this is hidden from
the end user.
