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.
Queries such as SHOW TABLES FROM db1 are now routed to the backend with db1.
This gives the correct result as long as db1 is not sharded to multiple
backends.
Moved hintfilter documentation to the correct place and cleaned it
up. Added a note at the start of the syntax documentation about the
behavior of the hint parsing to warn users of possible unexpected
behavior. The hint parsing could really use some refactoring to make it
more manageable which is why the preliminary fix version of the bug will
be 2.4.
This commit adds a new parameter that, when enabled, prunes the session
command history to a known length. This makes it possible to keep a
client-side pooled connection open indefinitely at the cost of making
reconnections theoretically unsafe. In practice the maximum history length
can be set to a value that encompasses a single session using the pooled
connection with no risk to session state integrity. The default history
length of 50 commands is quite likely to be adequate for the majority of
use-cases.
Both the replication lag and the message printing state are saved in SERVER,
although the values are mostly used by readwritesplit. A log message is printed
both when a server goes over the limit and when it comes back below.
Because of concurrency issues, a message may be printed multiple times before
different threads detect the new message state.
Documentation updated to explain the change.
Fixed the documentation on the arguments to maxkeys, which is a directory,
and added a short paragraph about alternative key file locations. Also
documented that keys are read from the directory where the `datadir`
parameter points to.
