MDEV-24853: Duplicate key generated during cluster configuration change

Incorrect processing of an auto-incrementing field in the WSREP-related code during applying transactions results in a duplicate key being created. This is due to the fact that at the beginning of the write_row() and update_row() functions, the values of the auto-increment parameters are used, which are read from the parameters of the current thread, but further along the code other values are used, which are read from global variables (when applying a transaction). This can happen when the cluster configuration has changed while applying a transaction (for example in the high_priority_service mode for Galera 4). Further during IST processing duplicating key is detected, and processing of the DB_DUPLICATE_KEY return code (inside innodb, in the write_row() handler) results in a call to the wsrep_thd_self_abort() function.
MariaDB · Mar 8, 2021 · 7345d37 · 7345d37
1 parent 545cba1
commit 7345d37
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Showing 6 changed files with 178 additions and 165 deletions.
diff --git a/include/mysql/service_wsrep.h b/include/mysql/service_wsrep.h
@@ -107,7 +107,6 @@ extern struct wsrep_service_st {
   bool                        (*wsrep_thd_ignore_table_func)(THD *thd);
   long long                   (*wsrep_thd_trx_seqno_func)(THD *thd);
   struct wsrep_ws_handle *    (*wsrep_thd_ws_handle_func)(THD *thd);
-  void                        (*wsrep_thd_auto_increment_variables_func)(THD *thd, unsigned long long *offset, unsigned long long *increment);
   void                        (*wsrep_set_load_multi_commit_func)(THD *thd, bool split);
   bool                        (*wsrep_is_load_multi_commit_func)(THD *thd);
   int                         (*wsrep_trx_is_aborting_func)(MYSQL_THD thd);
@@ -155,7 +154,6 @@ extern struct wsrep_service_st {
 #define wsrep_thd_ignore_table(T) wsrep_service->wsrep_thd_ignore_table_func(T)
 #define wsrep_thd_trx_seqno(T) wsrep_service->wsrep_thd_trx_seqno_func(T)
 #define wsrep_thd_ws_handle(T) wsrep_service->wsrep_thd_ws_handle_func(T)
-#define wsrep_thd_auto_increment_variables(T,O,I) wsrep_service->wsrep_thd_auto_increment_variables_func(T,O,I)
 #define wsrep_set_load_multi_commit(T,S) wsrep_service->wsrep_set_load_multi_commit_func(T,S)
 #define wsrep_is_load_multi_commit(T) wsrep_service->wsrep_is_load_multi_commit_func(T)
 #define wsrep_trx_is_aborting(T) wsrep_service->wsrep_trx_is_aborting_func(T)
@@ -212,7 +210,6 @@ my_bool wsrep_thd_is_BF(MYSQL_THD thd, my_bool sync);
 my_bool wsrep_thd_is_wsrep(MYSQL_THD thd);
 struct wsrep *get_wsrep();
 struct wsrep_ws_handle *wsrep_thd_ws_handle(THD *thd);
-void wsrep_thd_auto_increment_variables(THD *thd, unsigned long long *offset, unsigned long long *increment);
 void wsrep_set_load_multi_commit(THD *thd, bool split);
 bool wsrep_is_load_multi_commit(THD *thd);
 void wsrep_aborting_thd_enqueue(THD *thd);

diff --git a/mysql-test/suite/innodb/r/innodb-autoinc.result b/mysql-test/suite/innodb/r/innodb-autoinc.result
@@ -789,7 +789,7 @@ t2	CREATE TABLE `t2` (
   `n` int(10) unsigned NOT NULL,
   `o` enum('FALSE','TRUE') DEFAULT NULL,
   PRIMARY KEY (`m`)
-) ENGINE=InnoDB AUTO_INCREMENT=19 DEFAULT CHARSET=latin1
+) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=latin1
 INSERT INTO t1 (b,c) SELECT n,o FROM t2 ;
 SHOW CREATE TABLE t1;
 Table	Create Table

diff --git a/sql/sql_plugin_services.ic b/sql/sql_plugin_services.ic
@@ -177,7 +177,6 @@ static struct wsrep_service_st wsrep_handler = {
   wsrep_thd_ignore_table,
   wsrep_thd_trx_seqno,
   wsrep_thd_ws_handle,
-  wsrep_thd_auto_increment_variables,
   wsrep_set_load_multi_commit,
   wsrep_is_load_multi_commit,
   wsrep_trx_is_aborting,

diff --git a/sql/wsrep_dummy.cc b/sql/wsrep_dummy.cc
@@ -125,14 +125,6 @@ longlong wsrep_thd_trx_seqno(THD *)
 struct wsrep_ws_handle* wsrep_thd_ws_handle(THD *)
 { return 0; }
 
-void wsrep_thd_auto_increment_variables(THD *thd,
-                                        unsigned long long *offset,
-                                        unsigned long long *increment)
-{
-  *offset= thd->variables.auto_increment_offset;
-  *increment= thd->variables.auto_increment_increment;
-}
-
 void wsrep_set_load_multi_commit(THD *thd, bool split)
 { }
 

diff --git a/sql/wsrep_thd.cc b/sql/wsrep_thd.cc
@@ -851,27 +851,6 @@ bool wsrep_thd_has_explicit_locks(THD *thd)
   return thd->mdl_context.has_explicit_locks();
 }
 
-/*
-  Get auto increment variables for THD. Use global settings for
-  applier threads.
- */
-void wsrep_thd_auto_increment_variables(THD* thd,
-                                        unsigned long long* offset,
-                                        unsigned long long* increment)
-{
-  if (thd->wsrep_exec_mode == REPL_RECV &&
-      thd->wsrep_conflict_state != REPLAYING)
-  {
-    *offset= global_system_variables.auto_increment_offset;
-    *increment= global_system_variables.auto_increment_increment;
-  }
-  else
-  {
-    *offset= thd->variables.auto_increment_offset;
-    *increment= thd->variables.auto_increment_increment;
-  }
-}
-
 my_bool wsrep_thd_is_applier(MYSQL_THD thd)
 {
   my_bool is_applier= false;