MDEV-17571 : Make systemd timeout behavior more compatible with long Galera SSTs

This is 10.4 version.

Idea is to create monitor thread for both donor and joiner that will
periodically if needed extend systemd timeout while SST is being
processed. In 10.4 actual SST is executed by running SST script
and exchanging messages on pipe using blocking fgets. This fix
starts monitoring thread before SST script is started and
we stop monitoring thread when SST has been completed.

1 files changed, 32 insertions, 8 deletions

diff --git a/sql/wsrep_mysqld.cc b/sql/wsrep_mysqld.cc
index 24e5ac0e8d3..6692e8c4ef0 100644
--- a/sql/wsrep_mysqld.cc
+++ b/sql/wsrep_mysqld.cc
@@ -150,6 +150,10 @@ mysql_mutex_t LOCK_wsrep_config_state;
 mysql_mutex_t LOCK_wsrep_group_commit;
 mysql_mutex_t LOCK_wsrep_SR_pool;
 mysql_mutex_t LOCK_wsrep_SR_store;
+mysql_mutex_t LOCK_wsrep_joiner_monitor;
+mysql_mutex_t LOCK_wsrep_donor_monitor;
+mysql_cond_t  COND_wsrep_joiner_monitor;
+mysql_cond_t  COND_wsrep_donor_monitor;
 
 int wsrep_replaying= 0;
 ulong  wsrep_running_threads = 0; // # of currently running wsrep
@@ -160,7 +164,7 @@ ulong  wsrep_running_rollbacker_threads = 0; // # of running
 ulong  my_bind_addr;
 
 #ifdef HAVE_PSI_INTERFACE
-PSI_mutex_key 
+PSI_mutex_key
   key_LOCK_wsrep_replaying, key_LOCK_wsrep_ready, key_LOCK_wsrep_sst,
   key_LOCK_wsrep_sst_thread, key_LOCK_wsrep_sst_init,
   key_LOCK_wsrep_slave_threads, key_LOCK_wsrep_desync,
@@ -168,13 +172,15 @@ PSI_mutex_key
   key_LOCK_wsrep_group_commit,
   key_LOCK_wsrep_SR_pool,
   key_LOCK_wsrep_SR_store,
-  key_LOCK_wsrep_thd_queue;
+  key_LOCK_wsrep_thd_queue,
+  key_LOCK_wsrep_joiner_monitor,
+  key_LOCK_wsrep_donor_monitor;
 
 PSI_cond_key key_COND_wsrep_thd,
   key_COND_wsrep_replaying, key_COND_wsrep_ready, key_COND_wsrep_sst,
   key_COND_wsrep_sst_init, key_COND_wsrep_sst_thread,
-  key_COND_wsrep_thd_queue, key_COND_wsrep_slave_threads;
-  
+  key_COND_wsrep_thd_queue, key_COND_wsrep_slave_threads,
+  key_COND_wsrep_joiner_monitor, key_COND_wsrep_donor_monitor;
 
 PSI_file_key key_file_wsrep_gra_log;
 
@@ -192,7 +198,9 @@ static PSI_mutex_info wsrep_mutexes[]=
   { &key_LOCK_wsrep_config_state, "LOCK_wsrep_config_state", PSI_FLAG_GLOBAL},
   { &key_LOCK_wsrep_group_commit, "LOCK_wsrep_group_commit", PSI_FLAG_GLOBAL},
   { &key_LOCK_wsrep_SR_pool, "LOCK_wsrep_SR_pool", PSI_FLAG_GLOBAL},
-  { &key_LOCK_wsrep_SR_store, "LOCK_wsrep_SR_store", PSI_FLAG_GLOBAL}
+  { &key_LOCK_wsrep_SR_store, "LOCK_wsrep_SR_store", PSI_FLAG_GLOBAL},
+  { &key_LOCK_wsrep_joiner_monitor, "LOCK_wsrep_joiner_monitor", PSI_FLAG_GLOBAL},
+  { &key_LOCK_wsrep_donor_monitor, "LOCK_wsrep_donor_monitor", PSI_FLAG_GLOBAL}
 };
 
 static PSI_cond_info wsrep_conds[]=
@@ -203,7 +211,9 @@ static PSI_cond_info wsrep_conds[]=
   { &key_COND_wsrep_sst_thread, "wsrep_sst_thread", 0},
   { &key_COND_wsrep_thd, "THD::COND_wsrep_thd", 0},
   { &key_COND_wsrep_replaying, "COND_wsrep_replaying", PSI_FLAG_GLOBAL},
-  { &key_COND_wsrep_slave_threads, "COND_wsrep_wsrep_slave_threads", PSI_FLAG_GLOBAL}
+  { &key_COND_wsrep_slave_threads, "COND_wsrep_wsrep_slave_threads", PSI_FLAG_GLOBAL},
+  { &key_COND_wsrep_joiner_monitor, "COND_wsrep_joiner_monitor", PSI_FLAG_GLOBAL},
+  { &key_COND_wsrep_donor_monitor, "COND_wsrep_donor_monitor", PSI_FLAG_GLOBAL}
 };
 
 static PSI_file_info wsrep_files[]=
@@ -212,14 +222,17 @@ static PSI_file_info wsrep_files[]=
 };
 
 PSI_thread_key key_wsrep_sst_joiner, key_wsrep_sst_donor,
-  key_wsrep_rollbacker, key_wsrep_applier;
+  key_wsrep_rollbacker, key_wsrep_applier,
+  key_wsrep_sst_joiner_monitor, key_wsrep_sst_donor_monitor;
 
 static PSI_thread_info wsrep_threads[]=
 {
  {&key_wsrep_sst_joiner, "wsrep_sst_joiner_thread", PSI_FLAG_GLOBAL},
  {&key_wsrep_sst_donor, "wsrep_sst_donor_thread", PSI_FLAG_GLOBAL},
  {&key_wsrep_rollbacker, "wsrep_rollbacker_thread", PSI_FLAG_GLOBAL},
- {&key_wsrep_applier, "wsrep_applier_thread", PSI_FLAG_GLOBAL}
+ {&key_wsrep_applier, "wsrep_applier_thread", PSI_FLAG_GLOBAL},
+ {&key_wsrep_sst_joiner_monitor, "wsrep_sst_joiner_monitor", PSI_FLAG_GLOBAL},
+ {&key_wsrep_sst_donor_monitor, "wsrep_sst_donor_monitor", PSI_FLAG_GLOBAL}
 };
 
 #endif /* HAVE_PSI_INTERFACE */
@@ -788,6 +801,13 @@ void wsrep_thr_init()
                    &LOCK_wsrep_SR_pool, MY_MUTEX_INIT_FAST);
   mysql_mutex_init(key_LOCK_wsrep_SR_store,
                    &LOCK_wsrep_SR_store, MY_MUTEX_INIT_FAST);
+  mysql_mutex_init(key_LOCK_wsrep_joiner_monitor,
+                   &LOCK_wsrep_joiner_monitor, MY_MUTEX_INIT_FAST);
+  mysql_mutex_init(key_LOCK_wsrep_donor_monitor,
+                   &LOCK_wsrep_donor_monitor, MY_MUTEX_INIT_FAST);
+  mysql_cond_init(key_COND_wsrep_joiner_monitor, &COND_wsrep_joiner_monitor, NULL);
+  mysql_cond_init(key_COND_wsrep_donor_monitor, &COND_wsrep_donor_monitor, NULL);
+
   DBUG_VOID_RETURN;
 }
 
@@ -891,6 +911,10 @@ void wsrep_thr_deinit()
   mysql_mutex_destroy(&LOCK_wsrep_group_commit);
   mysql_mutex_destroy(&LOCK_wsrep_SR_pool);
   mysql_mutex_destroy(&LOCK_wsrep_SR_store);
+  mysql_mutex_destroy(&LOCK_wsrep_joiner_monitor);
+  mysql_mutex_destroy(&LOCK_wsrep_donor_monitor);
+  mysql_cond_destroy(&COND_wsrep_joiner_monitor);
+  mysql_cond_destroy(&COND_wsrep_donor_monitor);
 
   delete wsrep_config_state;
   wsrep_config_state= 0;                        // Safety