MDEV-30000: Force an InnoDB checkpoint in mariadb-backup

At the start of mariadb-backup --backup, trigger a flush of the
InnoDB buffer pool, so that as little log as possible will have
to be copied.

The previously debug-build-only interface
SET GLOBAL innodb_log_checkpoint_now=ON;
will be made available on all builds, and
mariadb-backup --backup will invoke it, unless the option
--skip-innodb-log-checkpoint-now is specified.

Reviewed by: Vladislav Vaintroub

Author: dr-m

extra/mariabackup/xtrabackup.cc

@@ -1381,6 +1381,7 @@ enum options_xtrabackup
   OPT_XTRA_MYSQLD_ARGS,
   OPT_XB_IGNORE_INNODB_PAGE_CORRUPTION,
   OPT_INNODB_FORCE_RECOVERY,
+  OPT_INNODB_CHECKPOINT,
   OPT_ARIA_LOG_DIR_PATH
 };
 
@@ -1790,6 +1791,8 @@ extern const char *io_uring_may_be_unsafe;
 bool innodb_use_native_aio_default();
 #endif
 
+static my_bool innodb_log_checkpoint_now;
+
 struct my_option xb_server_options[] =
 {
   {"datadir", 'h', "Path to the database root.", (G_PTR*) &mysql_data_home,
@@ -2017,6 +2020,12 @@ struct my_option xb_server_options[] =
    (G_PTR*)&srv_force_recovery,
    0, GET_ULONG, OPT_ARG, 0, 0, SRV_FORCE_IGNORE_CORRUPT, 0, 0, 0},
 
+  {"innodb_log_checkpoint_now", OPT_INNODB_CHECKPOINT,
+   "(for --backup): Force an InnoDB checkpoint",
+   (G_PTR*)&innodb_log_checkpoint_now,
+   (G_PTR*)&innodb_log_checkpoint_now,
+   0, GET_BOOL, OPT_ARG, 1, 0, 0, 0, 0, 0},
+
     {"mysqld-args", OPT_XTRA_MYSQLD_ARGS,
      "All arguments that follow this argument are considered as server "
      "options, and if some of them are not supported by mariabackup, they "
@@ -5403,6 +5412,14 @@ static bool xtrabackup_backup_func()
 	}
 	msg("cd to %s", mysql_real_data_home);
 	encryption_plugin_backup_init(mysql_connection);
+	if (innodb_log_checkpoint_now != false && mysql_send_query(
+		    mysql_connection,
+		    C_STRING_WITH_LEN("SET GLOBAL "
+				      "innodb_log_checkpoint_now=ON;"))) {
+		msg("initiating checkpoint failed");
+		return(false);
+	}
+
 	msg("open files limit requested %lu, set to %lu",
 	    xb_open_files_limit,
 	    xb_set_max_open_files(xb_open_files_limit));
@@ -5515,6 +5532,11 @@ static bool xtrabackup_backup_func()
 		goto fail;
 	}
 
+	/* try to wait for a log checkpoint, but do not fail if the
+	server does not support this */
+	if (innodb_log_checkpoint_now != false) {
+		mysql_read_query_result(mysql_connection);
+	}
 	/* label it */
 	recv_sys.file_checkpoint = log_sys.next_checkpoint_lsn;
 	log_hdr_init();

mysql-test/suite/encryption/t/doublewrite_debug.test

@@ -41,7 +41,7 @@ insert into t2 values (6, repeat('%', 400));
 # Copy the t1.ibd, t2.ibd file
 let $targetdir=$MYSQLTEST_VARDIR/tmp/backup_1;
 --disable_result_log
-exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf --backup --target-dir=$targetdir;
+exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf --backup --skip-innodb-log-checkpoint-now --target-dir=$targetdir;
 --enable_result_log
 
 echo # xtrabackup prepare;

mysql-test/suite/mariabackup/full_backup.result

@@ -1,7 +1,12 @@
 CREATE TABLE t(i INT) ENGINE INNODB;
 INSERT INTO t VALUES(1);
+SET GLOBAL innodb_max_purge_lag_wait=0;
 # xtrabackup backup
 NOT FOUND /InnoDB: Allocated tablespace ID/ in backup.log
+SELECT variable_value FROM information_schema.global_status
+WHERE variable_name = 'INNODB_BUFFER_POOL_PAGES_DIRTY';
+variable_value
+0
 INSERT INTO t VALUES(2);
 # xtrabackup prepare
 # shutdown server

mysql-test/suite/mariabackup/full_backup.test

@@ -2,6 +2,7 @@
 
 CREATE TABLE t(i INT) ENGINE INNODB;
 INSERT INTO t VALUES(1);
+SET GLOBAL innodb_max_purge_lag_wait=0;
 echo # xtrabackup backup;
 let $targetdir=$MYSQLTEST_VARDIR/tmp/backup;
 --let $backup_log=$MYSQLTEST_VARDIR/tmp/backup.log
@@ -18,6 +19,8 @@ exec $XTRABACKUP --defaults-file=$MYSQLTEST_VARDIR/my.cnf --backup --target-dir=
 --source include/search_pattern_in_file.inc
 --remove_file $backup_log
 
+SELECT variable_value FROM information_schema.global_status
+WHERE variable_name = 'INNODB_BUFFER_POOL_PAGES_DIRTY';
 INSERT INTO t VALUES(2);
 
 

mysql-test/suite/mariabackup/partial.result

@@ -4,8 +4,8 @@ CREATE TABLE t21(i INT) ENGINE INNODB;
 INSERT INTO t21 VALUES(1);
 CREATE TABLE t2(i int) ENGINE INNODB;
 # xtrabackup backup
-t1.new
-t21.new
+t1.ibd
+t21.ibd
 # xtrabackup prepare
 t1.cfg
 t21.cfg

mysql-test/suite/mariabackup/partial_exclude.result

@@ -14,7 +14,7 @@ INSERT INTO test.t1 VALUES(20);
 INSERT INTO test.t2 VALUES(20);
 # xtrabackup backup
 COMMIT;
-t1.new
+t1.ibd
 DROP TABLE t1;
 DROP TABLE t2;
 DROP DATABASE db2;

mysql-test/suite/mariabackup/unsupported_redo.result

@@ -22,8 +22,8 @@ CREATE TABLE t2(i int) ENGINE INNODB;
 ALTER TABLE t21 FORCE, ALGORITHM=INPLACE;
 # Create partial backup (excluding table t21), Ignore the
 # unsupported redo log for the table t21.
-t1.new
-t2.new
+t1.ibd
+t2.ibd
 # Prepare the full backup
 t1.ibd
 t2.ibd

mysql-test/suite/sys_vars/r/sysvars_innodb.result

@@ -1020,7 +1020,7 @@ SESSION_VALUE	NULL
 DEFAULT_VALUE	OFF
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	BOOLEAN
-VARIABLE_COMMENT	Force checkpoint now
+VARIABLE_COMMENT	Write back dirty pages from the buffer pool and update the log checkpoint
 NUMERIC_MIN_VALUE	NULL
 NUMERIC_MAX_VALUE	NULL
 NUMERIC_BLOCK_SIZE	NULL

storage/innobase/handler/ha_innodb.cc

@@ -18520,13 +18520,13 @@ static void innodb_buf_pool_update(THD *thd, st_mysql_sys_var *,
   mysql_mutex_unlock(&buf_pool.mutex);
 }
 
+static my_bool innodb_log_checkpoint_now;
 #ifdef UNIV_DEBUG
-static my_bool	innodb_log_checkpoint_now = TRUE;
 static my_bool	innodb_buf_flush_list_now = TRUE;
 static uint	innodb_merge_threshold_set_all_debug
 	= DICT_INDEX_MERGE_THRESHOLD_DEFAULT;
+#endif
 
-/** Force an InnoDB log checkpoint. */
 /** Force an InnoDB log checkpoint. */
 static
 void
@@ -18552,13 +18552,15 @@ checkpoint_now_set(THD* thd, st_mysql_sys_var*, void*, const void *save)
     ? SIZE_OF_FILE_CHECKPOINT + 8 : SIZE_OF_FILE_CHECKPOINT;
   mysql_mutex_unlock(&LOCK_global_system_variables);
   lsn_t lsn;
-  while (log_sys.last_checkpoint_lsn.load(std::memory_order_acquire) + size <
+  while (!thd_kill_level(thd) &&
+         log_sys.last_checkpoint_lsn.load(std::memory_order_acquire) + size <
          (lsn= log_sys.get_lsn(std::memory_order_acquire)))
     log_make_checkpoint();
 
   mysql_mutex_lock(&LOCK_global_system_variables);
 }
 
+#ifdef UNIV_DEBUG
 /****************************************************************//**
 Force a dirty pages flush now. */
 static
@@ -19130,12 +19132,12 @@ static MYSQL_SYSVAR_ULONG(io_capacity_max, srv_max_io_capacity,
   SRV_MAX_IO_CAPACITY_DUMMY_DEFAULT, 100,
   SRV_MAX_IO_CAPACITY_LIMIT, 0);
 
-#ifdef UNIV_DEBUG
 static MYSQL_SYSVAR_BOOL(log_checkpoint_now, innodb_log_checkpoint_now,
   PLUGIN_VAR_OPCMDARG,
-  "Force checkpoint now",
+  "Write back dirty pages from the buffer pool and update the log checkpoint",
   NULL, checkpoint_now_set, FALSE);
 
+#ifdef UNIV_DEBUG
 static MYSQL_SYSVAR_BOOL(buf_flush_list_now, innodb_buf_flush_list_now,
   PLUGIN_VAR_OPCMDARG,
   "Force dirty page flush now",
@@ -20213,8 +20215,8 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(monitor_reset_all),
   MYSQL_SYSVAR(purge_threads),
   MYSQL_SYSVAR(purge_batch_size),
-#ifdef UNIV_DEBUG
   MYSQL_SYSVAR(log_checkpoint_now),
+#ifdef UNIV_DEBUG
   MYSQL_SYSVAR(buf_flush_list_now),
   MYSQL_SYSVAR(merge_threshold_set_all_debug),
 #endif /* UNIV_DEBUG */