Add a new config variable wsrep_certification_rules

This is used for controlling whether to use a new/optimized
certification rules or the old/classic ones that could cause more
certification failures - when foreign keys are used and two INSERTs are
done concurrently to the child table from different nodes.

(cherry picked from commit 815d73e6af8daace6262ab63ca6c043ffc4204b3)

3 files changed, 15 insertions, 1 deletions

diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc
index 8a9120abdd0..d0b07472894 100644
--- a/sql/sys_vars.cc
+++ b/sql/sys_vars.cc
@@ -3887,6 +3887,19 @@ static Sys_var_mybool Sys_wsrep_certify_nonPK(
        GLOBAL_VAR(wsrep_certify_nonPK), 
        CMD_LINE(OPT_ARG), DEFAULT(TRUE));
 
+static const char *wsrep_certification_rules_names[]= { "strict", "optimized", NullS };
+static Sys_var_enum Sys_wsrep_certification_rules(
+       "wsrep_certification_rules",
+       "Certification rules to use in the cluster. Possible values are: "
+       "\"strict\": stricter rules that could result in more certification "
+       "failures. "
+       "\"optimized\": relaxed rules that allow more concurrency and "
+       "cause less certification failures.",
+       READ_ONLY GLOBAL_VAR(wsrep_certification_rules), CMD_LINE(REQUIRED_ARG),
+       wsrep_certification_rules_names, DEFAULT(WSREP_CERTIFICATION_RULES_STRICT),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0),
+       ON_UPDATE(0));
+
 static Sys_var_mybool Sys_wsrep_causal_reads(
        "wsrep_causal_reads", "(DEPRECATED) Setting this variable is equivalent "
        "to setting wsrep_sync_wait READ flag",
diff --git a/sql/wsrep_mysqld.cc b/sql/wsrep_mysqld.cc
index a7950754666..b61cebf6334 100644
--- a/sql/wsrep_mysqld.cc
+++ b/sql/wsrep_mysqld.cc
@@ -51,6 +51,7 @@ ulong   wsrep_max_ws_size              = 1073741824UL;//max ws (RBR buffer) size
 ulong   wsrep_max_ws_rows              = 65536; // max number of rows in ws
 int     wsrep_to_isolation             = 0; // # of active TO isolation threads
 my_bool wsrep_certify_nonPK            = 1; // certify, even when no primary key
+ulong   wsrep_certification_rules      = WSREP_CERTIFICATION_RULES_STRICT;
 long    wsrep_max_protocol_version     = 3; // maximum protocol version to use
 ulong   wsrep_forced_binlog_format     = BINLOG_FORMAT_UNSPEC;
 my_bool wsrep_recovery                 = 0; // recovery
diff --git a/sql/wsrep_mysqld.h b/sql/wsrep_mysqld.h
index b1dc5ba452b..e2800c8c2a8 100644
--- a/sql/wsrep_mysqld.h
+++ b/sql/wsrep_mysqld.h
@@ -20,6 +20,7 @@
 typedef struct st_mysql_show_var SHOW_VAR;
 #include <sql_priv.h>
 #include "../wsrep/wsrep_api.h"
+#include "wsrep_mysqld_c.h"
 
 #define WSREP_UNDEFINED_TRX_ID ULONGLONG_MAX
 
@@ -58,7 +59,6 @@ enum wsrep_consistency_check_mode {
     CONSISTENCY_CHECK_RUNNING,
 };
 
-
 // Global wsrep parameters
 extern wsrep_t*    wsrep;