By allowing transactions to the master to end even if the server is in
maintenance mode makes it possible to terminate connections at a known
point. This helps prevent interrupted transactions which can help reduce
errors that are visible to the clients.
The new `force=yes` option closes all connections to the server that is
being put into maintenance mode. This will immediately close all open
connections to the server without allowing results to return.
In this context master should be interpreted as "can be read
and written to".
Marking them as master requires less changes in RWS to make it
usable with a Clustrix cluster.
The masking_user test creates a database over a masked connection.
As 'CREATE DATABASE DB' is not fully parsed the test will fail since
it creates a database.
To allow the test to pass, we turn off the strict requirement that
all statements must be fully parsed.
If set to true and if any of the other blocking related parameters
is true, then a statement that cannot be fully parsed will be blocked.
Default is true.
That URL will now return information about the statements in
the query classifier cache. The information is collected using
the same map in a serial manner from all routing workers (that
each have their own cache). Since all caches will contains the
same statements, collecting the information in a serial manner
means that the overall memory consumption will be lower than
what it would be if the information was collected in parallel.
The documentation stated that MVCC reads weren't safe with
transaction_replay when in reality they are not safe in general and
transaction_replay has no effect on it.
The fact that two MaxScale processes can bind to the same port is now
possible due to the use of SO_REUSEPORT. As this is doable only with a
very deliberate setup, it is unlikely to be a practical problem in most
cases. Regardless, the test needs to be fixed to accept multiple MaxScales
bound to the same port.
With the addition of SO_REUSEPORT support, it is no longer possible to
rely on the network stack to prevent multiple listeners from listening on
the same port. Without explicitly checking for the ports it would be
possible for two listeners from two different services to listen on the
same port in which case the service would be almost randomly chosen.
If SO_REUSEPORT is available and the kernel supports it, listeners will
now listen on separate file descriptors. This removes the need for
cross-worker communication when in normal operation which should make
MaxScale scale better.
By storing the file descriptor inside a worker-local variable, it is
possible to handle both unique file descriptors (created with
SO_REUSEPORT) and shared file descriptors with the same code. The way in
which the file descriptor is stored in the rworker_local object determines
the way the listener behaves.
