The old message logged the function name and thread ID which are not useful
to the end user. The thread ID should only be printed for debugging purposes,
not general error messages.
The current implementation of idle connection timeouts is not safe. The sessions
are handled in a way which is not thread-safe and the checking is done from
a non-polling thread.
With this change, the checks for the session timeouts are done in one of the
polling threads in a thread-safe manner only if at least one service has enabled
the timing out of idle client connections.
The earlier log file based approach for enabling and disabling
messages has now been completely replaced with the syslog priority
based approach.
Similarly as with log files before it is now possible to enable
and disable a log priority for a particular session, even though
it apparently has not been used much.
The local test-programs of the logging has got minimal attention
only to make them compile. They should get an overhaul as they did
not work before either.
LOGIF and skygw_write_log removed from server/core/*.c and
replaced with calls to MXS_(ERROR|WARNING|NOTICE|INFO|DEBUG).
This is a mechanism change, no updating of the actual message
has been performed.
Currently this causes a very small performance hit, since the
check whether the priority is enabled or not is performed in
the function that is called and not before the function is called.
Once all LOGIFs and skygw_write_logs have been replaced, the
behaviour will be altered back to what it was.
The log manager variables lm_enabled_log_files_bitmask, log_ses_count
and tls_log_info that earlier were declared separately in every
c-file are now declared in the log_manager.h header.
tee.c: Added details about the freeing of orphaned sessions.
session.: Added missing cases of session state into the session_state function in debug builds.
http://bugs.skysql.com/show_bug.cgi?id=665http://bugs.skysql.com/show_bug.cgi?id=664http://bugs.skysql.com/show_bug.cgi?id=649
dcb.c:dcb_final_free: (665):set dcb->session->client pointer to NULL so that it won't be read anymore and other threads won't try to close it.
dcb_final_free:(664):don't free dcb->data, it is either freed in session_alloc if session creation fails or in session_free only.
session.c:if session creation fails, free dcb->data and remove links between client DCB and session.
mysql_backend.c:(665):gw_backend_close:check that session->client isn't NULL and that client DCB's state is still polling before calling dcb_close for it.
mysql_client.c:gw_mysql_do_authentication:if anything fails, and session_alloc won't be called, free dcb->data.
mysql_common.c:gw_send_authentication_to_backend:if session is already closing then return with error.
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.
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;
