When a DCB is removed and added more than once with poll_add_dcb and
poll_remove_dcb, the code previously chose a different thread each time
the DCB was added. This violated the assumption is that all DCBs are local
to a single worker.
The callbacks iterated over all threads when only the local ones must be
iterated. This prevents a deadlock from occurring when multiple threads
start throttling at the same time.
Also fixed the gwbuf_append debug assertion.
When a connection to a server is lost and the session command history is
disabled, the session will continue as long as at least one connection is
open. Previously the open connection calculation used the same code that
was used when a new session was created which only inspected the
configured server count instead of the actual open connection count.
Created the <maxbase/format.hh> header that contains various helper
functions for formatting values into human readable forms. Currently only
binary to human readable size conversion is implemented.
Drop the requirement that GTID based replication is used for
the BinLog Galera "failover" mechanism. There is no reason for
that restriction; it works just as well with file+position based
replication.
The table creation was not detected as the function used to extract the
table name did not return the fully qualified names. Even if it did return
a fully qualified name, it wouldn't have been correctly processed.
The setting didn't work because the code updated a status flag which
would be overwritten before being read. Also, promotion code now checks
that the server is not in maintenance.
The redirection method checks if a slave connection to the redirection
target already exists. If so, the connection is not modified. Also, failover
better detects duplicate connections during promotion.
The test did not use the wait_for_monitor function to sync with the
monitor. This function speeds up the testing greatly by removing
unnecessary sleeps from it.
Also reduced the amount of data inserted into the cluster. There's no real
need to test with large amounts of data as it is only a functional test.
When a read-only transaction fails due to a connection error, no message
would be logged. Also added an info level message for the case when a
backend connection would get closed before the session is in the correct
state and a debug assertion that the router session should never be closed
when the handleError method is called.
The removing and slave status updating is now separated to a function.
As the MariaDBServer object now contains the updated slave connections,
keeping track of removed connections is no longer required.
The two cases are now separated. In switchover, the promotion and
demotion targets can swap connections between each other without worry.
In failover, the two connection lists must be merged semi-intelligently.
The slave connections of the two servers are now saved to the operation
descriptor object at the start of the operation. This allows slave status
updating during the operation.
