MDEV-29986 Set innodb_undo_tablespaces=3 by default

Starting with commit baf276e6 (MDEV-19229)
the parameter innodb_undo_tablespaces can be increased from its
previous default value 0 while allowing an upgrade from old databases.

We will change the default setting to innodb_undo_tablespaces=3
so that the space occupied by possible bursts of undo log records
can be reclaimed after SET GLOBAL innodb_undo_log_truncate=ON.

We will not enable innodb_undo_log_truncate by default, because it
causes some observable performance degradation.

Special thanks to Thirunarayanan Balathandayuthapani for diagnosing
and fixing a number of bugs related to this new default setting.

Tested by: Matthias Leich, Axel Schwenke, Vladislav Vaintroub
(with both values of innodb_undo_log_truncate)

extra/mariabackup/xtrabackup.cc

@@ -1667,7 +1667,7 @@ struct my_option xb_server_options[] =
   {"innodb_undo_tablespaces", OPT_INNODB_UNDO_TABLESPACES,
    "Number of undo tablespaces to use.",
    (G_PTR*)&srv_undo_tablespaces, (G_PTR*)&srv_undo_tablespaces,
-   0, GET_UINT, REQUIRED_ARG, 0, 0, 126, 0, 1, 0},
+   0, GET_UINT, REQUIRED_ARG, 3, 0, 126, 0, 1, 0},
 
   {"innodb_compression_level", OPT_INNODB_COMPRESSION_LEVEL,
    "Compression level used for zlib compression.",

mysql-test/suite/encryption/r/innodb-spatial-index.result

@@ -38,6 +38,9 @@ INSERT INTO t2 values(1, 'secret', ST_GeomFromText('POINT(903994614 180726515)')
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION > 0;
 NAME
 innodb_system
+innodb_undo001
+innodb_undo002
+innodb_undo003
 mysql/innodb_index_stats
 mysql/innodb_table_stats
 mysql/transaction_registry

mysql-test/suite/innodb/r/innodb-system-table-view.result

@@ -10,7 +10,7 @@ TABLE_ID	NAME	FLAG	N_COLS	SPACE	ROW_FORMAT	ZIP_PAGE_SIZE	SPACE_TYPE
 11	SYS_FOREIGN	0	7	0	Redundant	0	System
 12	SYS_FOREIGN_COLS	0	7	0	Redundant	0	System
 13	SYS_VIRTUAL	0	6	0	Redundant	0	System
-16	mysql/transaction_registry	33	8	3	Dynamic	0	Single
+16	mysql/transaction_registry	33	8	6	Dynamic	0	Single
 SELECT table_id,pos,mtype,prtype,len,name
 FROM INFORMATION_SCHEMA.INNODB_SYS_COLUMNS
 WHERE table_id NOT IN (@table_stats_id, @index_stats_id)

mysql-test/suite/innodb/t/encryption_threads_shutdown.test

@@ -10,10 +10,20 @@ call mtr.add_suppression("Plugin 'InnoDB' registration as a STORAGE ENGINE faile
 --let $MYSQLD_DATADIR=`SELECT @@datadir`
 --let $DATA= $MYSQLD_DATADIR/ibdata1
 --let $DATACOPY=$MYSQLTEST_VARDIR/tmp/ibdata1
+--let $UNDO_1= $MYSQLD_DATADIR/undo001
+--let $UNDO_2= $MYSQLD_DATADIR/undo002
+--let $UNDO_3= $MYSQLD_DATADIR/undo003
+--let $UNDO_1_COPY=$MYSQLTEST_VARDIR/tmp/undo001
+--let $UNDO_2_COPY=$MYSQLTEST_VARDIR/tmp/undo002
+--let $UNDO_3_COPY=$MYSQLTEST_VARDIR/tmp/undo003
+
 CREATE TABLE t(a INT) ENGINE=InnoDB;
 --source include/kill_mysqld.inc
 # Move the file to cause srv_init_abort_low() call from srv_start()
 --move_file $DATA $DATACOPY
+--move_file $UNDO_1 $UNDO_1_COPY
+--move_file $UNDO_2 $UNDO_2_COPY
+--move_file $UNDO_3 $UNDO_3_COPY
 
 # If the bug is not fixed, the server will hang here. Note that the test is
 # unstable because the condition
@@ -28,5 +38,8 @@ CREATE TABLE t(a INT) ENGINE=InnoDB;
 SELECT * FROM t;
 --source include/kill_mysqld.inc
 --move_file $DATACOPY $DATA
+--move_file $UNDO_1_COPY $UNDO_1
+--move_file $UNDO_2_COPY $UNDO_2
+--move_file $UNDO_3_COPY $UNDO_3
 --source include/start_mysqld.inc
 DROP TABLE t;

mysql-test/suite/innodb/t/log_data_file_size.opt

 --loose-innodb-sys-indexes
 --innodb-data-file-path=ibdata1:1M:autoextend
+--innodb-undo-tablespaces=0

mysql-test/suite/innodb/t/row_format_redundant.opt

 --innodb-checksum-algorithm=crc32
+--innodb-undo-tablespaces=0

mysql-test/suite/innodb/t/table_flags.opt

 --innodb-checksum-algorithm=crc32
---skip-innodb-read-only-compressed
+--innodb-undo-tablespaces=0

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

@@ -1653,7 +1653,7 @@ READ_ONLY	NO
 COMMAND_LINE_ARGUMENT	OPTIONAL
 VARIABLE_NAME	INNODB_UNDO_TABLESPACES
 SESSION_VALUE	NULL
-DEFAULT_VALUE	0
+DEFAULT_VALUE	3
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	INT UNSIGNED
 VARIABLE_COMMENT	Number of undo tablespaces to use.

plugin/hashicorp_key_management/mysql-test/vault/t/hashicorp_key_rotation_age.test

@@ -33,7 +33,7 @@ let $restart_parameters=$default_parameters --innodb_encryption_threads=5 --inno
 
 --echo # Wait until encryption threads have encrypted all tablespaces
 
---let $tables_count= `select count(*) + 1 from information_schema.tables where engine = 'InnoDB'`
+--let $tables_count= `select count(*) + 1 + @@global.innodb_undo_tablespaces from information_schema.tables where engine = 'InnoDB'`
 --let $wait_timeout= 600
 --let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 --source include/wait_condition.inc
@@ -63,7 +63,7 @@ alter table t33 encryption_key_id=222;
 
 --echo # Wait until encryption threads have encrypted all tablespaces
 
---let $tables_count= `select count(*) from information_schema.tables where engine = 'InnoDB'`
+--let $tables_count= `select count(*) + @@global.innodb_undo_tablespaces from information_schema.tables where engine = 'InnoDB'`
 --let $wait_timeout= 600
 --let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 --source include/wait_condition.inc
@@ -77,7 +77,7 @@ set global innodb_encrypt_tables = OFF;
 
 --echo # Wait until encryption threads to decrypt all encrypted tablespaces
 
---let $tables_count= `select count(*) - 1 from information_schema.tables where engine = 'InnoDB'`
+--let $tables_count= `select count(*) - 1 + @@global.innodb_undo_tablespaces from information_schema.tables where engine = 'InnoDB'`
 --let $wait_timeout= 600
 --let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0 AND ROTATING_OR_FLUSHING = 0;
 --source include/wait_condition.inc
@@ -105,7 +105,7 @@ set global innodb_encrypt_tables = ON;
 
 --echo # Wait until encryption threads to encrypt all unencrypted tablespaces
 
---let $tables_count= `select count(*) from information_schema.tables where engine = 'InnoDB'`
+--let $tables_count= `select count(*) + @@global.innodb_undo_tablespaces from information_schema.tables where engine = 'InnoDB'`
 --let $wait_timeout= 600
 --let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 --source include/wait_condition.inc

storage/innobase/buf/buf0buf.cc

@@ -588,7 +588,7 @@ bool buf_page_is_corrupted(bool check_lsn, const byte *read_buf,
 		DBUG_EXECUTE_IF(
 			"page_intermittent_checksum_mismatch", {
 			static int page_counter;
-			if (page_counter++ == 3) {
+			if (page_counter++ == 6) {
 				crc32++;
 			}
 		});
@@ -723,7 +723,8 @@ bool buf_page_is_corrupted(bool check_lsn, const byte *read_buf,
 			DBUG_EXECUTE_IF(
 				"page_intermittent_checksum_mismatch", {
 				static int page_counter;
-				if (page_counter++ == 3) return true;
+				if (page_counter++ == 6)
+					return true;
 			});
 
 			if ((checksum_field1 != crc32

storage/innobase/handler/ha_innodb.cc

@@ -19345,7 +19345,7 @@ static MYSQL_SYSVAR_UINT(undo_tablespaces, srv_undo_tablespaces,
   PLUGIN_VAR_RQCMDARG | PLUGIN_VAR_READONLY,
   "Number of undo tablespaces to use.",
   NULL, NULL,
-  0L,			/* Default seting */
+  3L,			/* Default seting */
   0L,			/* Minimum value */
   TRX_SYS_MAX_UNDO_SPACES, 0); /* Maximum value */