If a connection is killed but the backend DCBs have not yet received their
thread IDs, the connections can be forcibly closed. This removes the
possibility of stale connections caused by an unfortunately timed KILL
query to a session that has partially connected to some servers.
Returning the length of the value instead of a boolean allows the user to
know when the parameter value exceeded the buffer size passed as the
parameter.
To support a wider range of client connectors, MaxScale should respond
with an AuthSwitchRequest packet to all COM_CHANGE_USER commands. Only
MariaDB connectors understand the OK packet as the only response to a
COM_CHANGE_USER but all connectors understand the AuthSwitchRequest
packet.
The mysql_create_standard_error function accepted a packet number as a
parameter but did not use it as the actual packet number. As the value it
used happened to coincide with 50% of the use-cases, it went unnoticed.
The remaining 50% occurred when a KILL command was executed with an
unknown connection ID.
The individual servers were missing a statistic that would give an
estimated query count. As there is no simple way to count queries for all
modules, counting the number of routed protocol packets is a suitable
substitute.
Accidental modifications of scripts/programs are more likely if the owner
has write permissions on the file. In addition, they are not required and
thus can be removed.
The same problem that caused maxadmin to lock up was also what caused
maxinfo to lock up. The concurrent access to the legacy administrative
functions caused deadlocks.
The resultset processing for MySQL requires some extra work as it lacks
the proper SERVER_MORE_RESULTS_EXIST flag in the last EOF packet. Instead,
the first EOF packet has the SERVER_PS_OUT_PARAMS flag which needs to be
interpreted as a SERVER_MORE_RESULTS_EXIST flag for the second EOF packet.
Also corrected the EOF packet handling to do the flag checks in the code
that deals with the EOF packets.
As the modutil_state parameter is now used for more than large packet
tracking, the correct solution is to store this state object in the
readwritesplit session instead of interpreting it to a boolean value.
Earlier only "SELECT NEXT VALUE FOR SEQ" was parsed
properly, while "SELECT PREVIOUS VALUE FOR SEQ" was not.
Now the latter statement is also parsed properly.
In this case, the server was already a slave and is not being demoted. Also, the file may
contain queries which cannot be ran while a slave connection is running.
