The feature was rarely used and was only useful in extremely rare
cases. The functionality can still be emulated, if for some reason needed,
by pointing `logdir` to `/dev/shm` or another tmpfs mount.
- Cannot be supported with std::thread.
- Unlikely that the default size (8MB) would ever be too small and
if it is, there is some problem.
- The stack size can be specified using 'ulimit -s' before starting
MaxScale.
Enabling it with a value of 1 should remove the vast majority of
connection related problems that appear in MaxScale. This should filter
out most of the errors caused by transient network problems.
Relaced router_options with configuration parameters in the createInstance
router entry point. The same needs to be done for the filter API as barely
any filters use the feature.
Some routers (binlogrouter) still support router_options but using it is
deprecated. This had to be done as their use wasn't deprecated in 2.2.
To prepare the router's for the eventual removal of the router_options
parameter, the API option arguments should not be used. The parameters can
be substituted by tokenizing the value of the parameter that is still
stored as a part of the service.
It is now possible to prevent the masking filter from rejecting
statements using functions in conjunction with fields to be
masked. So now it is possible to not use the blanket rejection
of the masking filter and replace it with more detailed firewall
rules.
The code in avrorouter that returned the current transaction was not very
useful and it can be acquired via the REST API in a more convenient
format.
The number of created sessions is tracked on the service level so there is
no need to track it in the avrorouter.
Removed declarations for functions that do not exist and moved code around
to reduce the scope.
Enabling the session command history but limiting it to a history of 50
commands allows reconnections for sessions that don't change the state too
often.
As pooled connections will exceed this limit quite fast, they are not able
to reconnect to servers once connections are lost. To solve this problem,
the session command history needs a compaction process that removes
redundant history.
