readwritesplit.c:route_session_write failed if the last backend on all backends list was not in use. THe situation where not all backends are used by routing session is normal especially if max_slave_connections is not set to 100%. Thus session commands may have failed if user was bit unlucky.
Changed the logic so that the function fails (and session is closed) if routing fails to any such backend which is in use in the session.
Added server references to services instead of using a raw pointers to server instances.
Changed all references to service->database to service->dbref.
readwritesplit.h:Removed invalid macros which assumed that ROUTER_CLIENT_SES->rses_backend_ref always pointed to valid and used backend reference and thus included potential risk of NULL-pointer refernce.
mysql_backend.c and mysql_client.c:avoid executing CHK_PROTOCOL(p) after original DCB has been released the memory.
readwritesplit.c:Replaced RSES_CLEINT_DCB macro with a function which returns client DCB for a given router client session.
session.c:session_free:if session is child of another service (tee in this case), it is the parent which releases child's allocated memory back to the system. This now also includes the child router session.
dcb.h: Added DCB_IS_CLONE macro
tee.c:freeSession:if parent session triggered closing of tee, then child session may not be closed yet. In that case free the child session first and only then free child router session and release child session's memory back to system.
tee.c:routeQuery: only route if child session is ready for routing. Log if session is not ready for routing and set tee session inactive
mysql_client.c:gw_client_close:if DCB is cloned one don't close the protocol because they it is shared with the original DCB.
dcb.c:dcb_clone: set same close function than in the original DCB so that routing session will become closed when client DCB is closed.
session.h:introduce a new state which indicates that SESSION structure can be freed next, SESSION_STATE_TO_BE_FREED. State is needed to separate the state before and after memory free. Memory is freed in different situation depending on whether the session is parent or child session. Child sessions are freed in their parent.
Also introduce a new member in SESSION struct, ses_is_child, to indicate whether SESSION has a parent session which is responsible for releasing the memory of it.
session.c:session_unlink_dcb:when last session reference is removed set SESSION->state=SESSION_STATE_TO_BE_FREED
session.c:session_free:only free the memory if session is not child session. If it is child, session is left to be freed by the parent (in tee filter's freeSession, for example).
tee.c:newSession:mark branch session to child.
tee.c:freeSession:if child session memory is ready to be freed, free it.
mysql_mon.c:monitorMain:when backend server's status changes so that it is not running anymore or doesn't have any of the states - master, slave, ndb, joined - call for each DCB the callback-function DCB_REASON_NOT_RESPONDING if specified. Earlier callbacks were called if there was any change in the state of the server being monitored.
server.c: Added new member to SERVER->master_err_is_logged. It is used if server loses master status. It causes error log print in readwritesplit router's eror handling. Initial value is false and it is set always to false when server's status is set to master.
Added message log printing to mysql monitor, if master status changes to something else. It is not warning or error but only information which probably interests the user.
readwritesplit.c:Muted warnings and error printings in cases if slaves are not found if it is allowed to have a master only.
readwritesplit.c:Corrected error log printing in case where master lost its status. REdundant prints are removed.
Situation is wrong because client shouldn't send new query before the previous (the pending one) is executed in backend and the reply is sent to the client.
tee.c:closeSession removed unnecessary dcb_free, router/service closes all backend DCBs and the client DCB, and client DCB is the one that was tried to free in closeSession.
readwritesplit.c:routeQuery now handles untyped and typed GWBUFs. Untyped means that read buffer may consist of incomplete and multiple MySQL packets. Typed buffer always consists of a single MySQL packet (which can be split to many buffers inside GWBUF).
Fixed Coverity cases #84840 and #84841
If readwritesplit.c:routeQuery gets a GWBUF whose type is UNDEFINED, then each MySQL packet is extracted from input buffer and passed to new function, route_single_stmt. Each extracted packet is stored in separate GWBUF and added types GWBUF_TYPE_MYSQL and GWBUG_TYPE_SINGLE_STMT which makes it possible to execute session commands and process reply packets properly.
Code nedes still cleaning but this is for testing atm.
dbshard.h:removed unnecessary code
dbshard.c:removed unnecessary code, cleaned up a bit and made some required changes
readwritesplit.c:removed two unnecessary variable assignments.
void session_enable_log(SESSION* ses, logfile_id_t id)
and
void session_disable_log(SESSION* ses, logfile_id_t id)
Which switch specific log type on/off if the log type in question is not generally enabled.
Each thread carries a thread-specific struct log_info_t which includes members for current session id and bitfield for enabled log types for the current session. That information is checked before actual log write functions are called.
Each file where session-specific logging is used, must include the following exports:
/** Defined in log_manager.cc */
extern int lm_enabled_logfiles_bitmask;
extern size_t log_ses_count[];
extern __thread log_info_t tls_log_info;
