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.
Session commands that span multiple packets are now allowed and will
work. However, if one is executed the session command history is disabled
as no interface for appending to session commands exists.
The backend protocol modules now also correctly track the current
command. This was a pre-requisite for large session commands as they
needed to be gathered into a single buffer and to do this the current
command had to be accurate.
Updated tests to expect success instead of failure for large prepared
statements.
The SESSION_TRACK_SCHEMA tracking capability handling assumed an encoding
integer in the data. This value does not exist for the data returned by
schema change or session state tracking.
The COM_STMT_FETCH command will create a response. This was a
readwritesplit-specific interpretation of the command and it was wrong.
Also record the currently executed command event for session commands.
The old hkheartbeat variable was changed to the mxs_clock() function that
simply wraps an atomic load of the variable. This allows it to be
correctly read by MaxScale as well as opening up the possibility of
converting the value load to a relaxed memory order read.
Renamed the header and associated macros. Removed inclusion of the
heartbeat header from the housekeeper header and added it to the files
that were missing it.
Moved the RWBackend class implementation into its own file. Made some of
the command type functions a part of the <maxscale/protocol/mysql.h>
header to make it reusable.
The DCB pointer in the MySQLProtocol struct doesn't appear to be updated
in all cases which causes it to be an unreliable source. As the session
itself is always available and it always has the service pointer properly
set, it should be used instead.
Also removed the dead protocol compression code and replaced the
parameters with the service capability bits.
By making it conditional, we prevent the problems that arise when the
replication protocol is used in combination with the session state change
tracking. In addition to this, it prevents unnecessary work for routers
and filters that don't need it.
When backend SSL connections were created, the connection creation was
done twice. This was due to the lacking detection of an already
established SSL connection.
* MXS-199: Support Causal Read in Read Write Splitting
* move most causal read logic into rwsplit router and get server type from monitor
* misc fix: remove new line
* refactor, move config to right place, replace ltrim with gwbuf_consume
* refacter a little for previous commit
* fix code style
Length-encoded strings should be consumed with the correct
functions. Doing pointer arithmetic with the same pointer as a parameter
appears to fail only on CentOS 6 whereas on newer systems it performs as
expected.
The result collection did not reset properly when a non-resultset was
returned for a request. As collected result need to be distinguishable
from single packet responses, a new buffer type was added.
The new buffer type is used by readwritesplit which uses result collection
for preparation of prepared statements.
Moved the current command tracking to the RWBackend class as the command
tracked by the protocol is can change before a response to the executed
command is received.
Removed a false debug assertion in the mxs_mysql_extract_ps_response
function that was triggered when a very large prepared statement response
was processed in multiple parts.
KILL commands are now sent to the backends in an asynchronous manner. As
the LocalClient class is used to connect to the servers, this will cause
an extra connection to be created on top of the original connections
created by the session.
If the user does not have the permissions to execute the KILL, the error
message is currently lost. This could be solved by adding a "result
handler" into the LocalClient class which is called with the result.
