proxysql

Commit Graph

Author	SHA1	Message	Date
Rene Cannao	2a7bddca28	MySrvC: rename server_backoff_time to session_track_backoff_until, gate hot-path read Context ------- PR #5166 introduced a per-'MySrvC' atomic timestamp that prevents the server from being chosen for new connections for a 30-second window. The timestamp is written in exactly one place, 'MySQL_Session::handle_session_track_capabilities()', and only when 'mysql-session_track_variables' is in ENFORCED mode and the backend is missing 'CLIENT_SESSION_TRACKING' or 'CLIENT_DEPRECATE_EOF'. The field was originally named 'server_backoff_time' and its only semantics were that ENFORCED-mode capability mismatches temporarily exclude the server from selection. Two issues with the original shape: 1. The name does not hint that the scope is session-tracking capability enforcement. A reader of 'MyHGC::get_random_MySrvC' or 'MySQL_Thread::get_MyConn_local' had no way to tell that this field is tied to one specific feature and not, say, a generic health backoff. 2. The atomic load was unconditional in both hot selection loops. Even though the atomic is relaxed (effectively a 'mov' on x86), per-iteration atomic reads inhibit hoisting and CSE that the compiler can otherwise apply to thread-local integer reads. 'get_random_MySrvC' runs the loop over every server in the hostgroup on every backend-connection acquisition, so this is the sort of place where small per-iteration costs accumulate. Changes ------- * Rename the field: MySrvC::server_backoff_time -> MySrvC::session_track_backoff_until Naming it after the feature makes it obvious that the field is specific to session-tracking enforcement and should not be overloaded for unrelated purposes (e.g. connect errors, monitor failures). If a future change needs a generic backoff mechanism, a new field -- or a rename at that point -- keeps intent clear rather than piggy-backing on this one silently. * Gate the atomic load on mode: In both 'MyHGC::get_random_MySrvC()' (lib/MyHGC.cpp) and 'MySQL_Thread::get_MyConn_local()' (lib/MySQL_Thread.cpp), the relaxed load is skipped entirely when 'mysql_thread___session_track_variables' is not ENFORCED. In 'get_MyConn_local' the check is computed once before the loop; in 'get_random_MySrvC' the check is inside the loop but is a thread-local int read, which is free. Correctness note: switching out of ENFORCED at runtime makes any stale 'session_track_backoff_until' values in the pool immediately ignored, which is the desired behavior -- servers rejected while ENFORCED was active become eligible again the moment the operator relaxes the mode, matching how ProxySQL handles other runtime-variable-dependent state. No explicit reset is required. * Updated the field documentation in include/MySQL_HostGroups_Manager.h with the monotonic-timestamp unit, the list of sites that read/write it, the explicit scope (ENFORCED mode only), and the reset policy (no explicit reset; deadline ages out by comparison against curtime). No functional change for DISABLED / OPTIONAL configurations (the default for all installations). ENFORCED mode behaviour is unchanged.	1 month ago
Wazir Ahmed	f815b77812	fix: make server_backoff_time atomic Signed-off-by: Wazir Ahmed <wazir@proxysql.com>	1 month ago
Wazir Ahmed	f0ac86c317	Enable session tracking based on server capabilities Signed-off-by: Wazir Ahmed <wazir@proxysql.com>	5 months ago
Rahim Kanji	c7cf5ba344	Removed MySrvStatus class	2 years ago
Rahim Kanji	4da04c0282	Merge remote-tracking branch 'Master/v2.x' into v2.x_hostgroup_online_servers	2 years ago
Rahim Kanji	a081695ae9	* Solved few warnings * Enforced explicit conversion of MySrvStatus	2 years ago
René Cannaò	73b7b543b8	Fixed a compilation with TEST_AURORA	2 years ago
Rahim Kanji	42c8bb83c6	Few fixes	2 years ago
Rahim Kanji	eb09e6766b	Merge remote-tracking branch 'Master/v2.x' into v2.x_hostgroup_online_servers # Conflicts: # lib/MySQL_HostGroups_Manager.cpp	2 years ago
René Cannaò	e7aa5ff4c5	Split of MySQL_HostGroups_Manager.cpp into multiple files First commit to split MySQL_HostGroups_Manager.cpp into multiple files. More to split.	2 years ago

10 Commits (6d8dff293973edd1be9cc67be03aac400e85cb4c)