MDEV-33145 Add FLUSH GLOBAL STATUS

- FLUSH GLOBAL STATUS now resets most global_status_vars.
  At this stage, this is mainly to be used for testing.
- FLUSH SESSION STATUS added as an alias for FLUSH STATUS.
- FLUSH STATUS does not require any privilege (before required RELOAD).
- FLUSH GLOBAL STATUS requires RELOAD privilege.
- All global status reset moved to FLUSH GLOBAL STATUS.
- Replication semisync status variables are now reset by
  FLUSH GLOBAL STATUS.
- In test cases, the only changes are:
  - Replace FLUSH STATUS with FLUSH GLOBAL STATUS
  - Replace FLUSH STATUS with FLUSH STATUS; FLUSH GLOBAL STATUS.
    This was only done in a few tests where the test was using SHOW STATUS
    for both local and global variables.
- Uptime_since_flush_status is now always provided, independent if
  ENABLED_PROFILING is enabled when compiling MariaDB.
- @@global.Uptime_since_flush_status is reset on FLUSH GLOBAL STATUS
  and @@session.Uptime_since_flush_status is reset on FLUSH SESSION STATUS.
- When connected, @@session.Uptime_since_flush_status is set to 0.

Author: montywi

client/mysqladmin.cc

@@ -985,7 +985,7 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
     }
     case ADMIN_FLUSH_STATUS:
     {
-      if (flush(mysql, "status"))
+      if (flush(mysql, "/*!110500 global */ status"))
 	return -1;
       break;
     }
@@ -1034,8 +1034,9 @@ static int execute_commands(MYSQL *mysql,int argc, char **argv)
     }
     case ADMIN_FLUSH_ALL_STATUS:
     {
-      if (flush(mysql, "status,table_statistics,index_statistics,"
-                       "user_statistics,client_statistics"))
+      if (flush(mysql,
+                "/*!110500 global */ status,table_statistics,"
+                "index_statistics, user_statistics,client_statistics"))
 	return -1;
       break;
     }

include/mysql_com.h

@@ -194,10 +194,11 @@ enum enum_indicator_type
 #define REFRESH_LOG             (1ULL << 1)  /* Start on new log file */
 #define REFRESH_TABLES          (1ULL << 2)  /* close all tables */
 #define REFRESH_HOSTS           (1ULL << 3)  /* Flush host cache */
-#define REFRESH_STATUS          (1ULL << 4)  /* Flush status variables */
+#define REFRESH_SESSION_STATUS  (1ULL << 4)  /* Flush status variables */
+#define REFRESH_STATUS REFRESH_SESSION_STATUS
 #define REFRESH_THREADS         (1ULL << 5)  /* Flush thread cache */
-#define REFRESH_SLAVE           (1ULL << 6)  /* Reset master info and restart slave
-                                             thread */
+#define REFRESH_SLAVE           (1ULL << 6)  /* Reset master info and restart
+                                                slave thread */
 #define REFRESH_MASTER          (1ULL << 7)  /* Remove all bin logs in the index
                                              and truncate the index */
 
@@ -218,6 +219,7 @@ enum enum_indicator_type
 #define REFRESH_USER_RESOURCES  (1ULL << 19)
 #define REFRESH_FOR_EXPORT      (1ULL << 20) /* FLUSH TABLES ... FOR EXPORT */
 #define REFRESH_SSL             (1ULL << 21)
+#define REFRESH_GLOBAL_STATUS   (1ULL << 22)  /* Flush global status */
 
 #define REFRESH_GENERIC         (1ULL << 30)
 #define REFRESH_FAST            (1ULL << 31) /* Intern flag */

mysql-test/include/check_key_reads.inc

@@ -2,5 +2,5 @@
 let $key_reads= query_get_value(SHOW STATUS LIKE 'key_reads',Value,1);
 --disable_query_log
 eval SELECT IF($key_reads = 0, "Yes!", "No!") as 'Zero key reads?';
-FLUSH STATUS;
+FLUSH GLOBAL STATUS;
 --enable_query_log

mysql-test/include/query_cache.inc

@@ -31,7 +31,7 @@ set GLOBAL query_cache_size = 1355776;
 #
 # Without auto_commit.
 #
-flush status;
+flush global status;
 set autocommit=0;
 eval create table t1 (a int not null)$partitions_a;
 insert into t1 values (1),(2),(3);
@@ -129,7 +129,7 @@ connection default;
 SHOW VARIABLES LIKE 'have_query_cache';
 
 SET GLOBAL query_cache_size = 204800;
-flush status;
+flush global status;
 SET @@autocommit=1;
 eval SET SESSION DEFAULT_STORAGE_ENGINE = $engine_type;
 eval CREATE TABLE t2 (s1 int, s2 varchar(1000), key(s1))$partitions_s1;

mysql-test/include/query_cache_partitions.inc

@@ -40,7 +40,7 @@ show create table t1;
 
 INSERT INTO t1 VALUES (1, now(), 0);
 
-flush status;
+flush global status;
 show status like "Qcache_queries_in_cache";
 show status like "Qcache_hits";
 
@@ -76,7 +76,7 @@ show create table t1;
 
 INSERT INTO t1 VALUES (1, now(), 0);
 
-flush status;
+flush global status;
 show status like "Qcache_queries_in_cache";
 show status like "Qcache_hits";
 
@@ -97,7 +97,7 @@ drop table t1;
 --echo #
 
 flush query cache;
-flush status;
+flush global status;
 
 SET GLOBAL query_cache_size=1024*1024*512;
   CREATE TABLE `t1` (

mysql-test/include/query_cache_sql_prepare.inc

@@ -30,7 +30,7 @@ connection default;
 
 set @initial_query_cache_size = @@global.query_cache_size;
 set @@global.query_cache_size=102400;
-flush status;
+flush global status;
 --disable_warnings
 drop table if exists t1;
 --enable_warnings
@@ -485,7 +485,7 @@ drop table if exists t1;
 --enable_warnings
 create table t1 (a varchar(255));
 insert into t1 (a) values ("Pack my box with five dozen liquor jugs.");
-flush status;
+flush global status;
 prepare stmt from "select a from t1";
 execute stmt;
 set @@global.query_cache_size=0;

mysql-test/main/cache_innodb.result

@@ -4,7 +4,7 @@ SET SESSION DEFAULT_STORAGE_ENGINE = InnoDB;
 drop table if exists t1,t2,t3;
 set @save_query_cache_size = @@global.query_cache_size;
 set GLOBAL query_cache_size = 1355776;
-flush status;
+flush global status;
 set autocommit=0;
 create table t1 (a int not null);
 insert into t1 values (1),(2),(3);
@@ -139,7 +139,7 @@ SHOW VARIABLES LIKE 'have_query_cache';
 Variable_name	Value
 have_query_cache	YES
 SET GLOBAL query_cache_size = 204800;
-flush status;
+flush global status;
 SET @@autocommit=1;
 SET SESSION DEFAULT_STORAGE_ENGINE = InnoDB;
 CREATE TABLE t2 (s1 int, s2 varchar(1000), key(s1));

mysql-test/main/connect.result

@@ -285,7 +285,7 @@ DROP USER mysqltest_u1@localhost;
 
 # -- Bug#35074: max_used_connections is not correct.
 
-FLUSH STATUS;
+FLUSH GLOBAL STATUS;
 
 SHOW STATUS LIKE 'max_used_connections';
 Variable_name	Value
@@ -422,7 +422,7 @@ Warning	1287	'@@secure_auth' is deprecated and will be removed in a future relea
 # MDEV-19277: Add status variable that gets incremented if
 # connection is aborted prior to authentication
 #
-flush status;
+flush global status;
 SHOW GLOBAL STATUS LIKE 'Aborted_connects%';
 Variable_name	Value
 Aborted_connects	0

mysql-test/main/connect.test

@@ -267,7 +267,7 @@ DROP USER mysqltest_u1@localhost;
 --echo # -- Bug#35074: max_used_connections is not correct.
 --echo
 
-FLUSH STATUS;
+FLUSH GLOBAL STATUS;
 
 --echo
 SHOW STATUS LIKE 'max_used_connections';
@@ -462,7 +462,7 @@ SET global secure_auth=default;
 --echo # connection is aborted prior to authentication
 --echo #
 
-flush status;
+flush global status;
 SHOW GLOBAL STATUS LIKE 'Aborted_connects%';
 
 SET GLOBAL log_warnings=2;

mysql-test/main/features.result

@@ -1,6 +1,6 @@
 drop table if exists t1;
 set sql_mode="";
-flush status;
+flush global status;
 show status like "feature%";
 Variable_name	Value
 Feature_application_time_periods	0