MDEV-19229 Allow innodb_undo_tablespaces to be changed after database creation

trx_sys_t::undo_log_nonempty: Set to true if there are undo logs to rollback and purge. The algorithm for re-creating the undo tablespace when trx_sys_t::undo_log_nonempty is disabled: 1) trx_sys_t::reset_page(): Reset the TRX_SYS page and assign all rollback segment slots from 1..127 to FIL_NULL 2) Free the rollback segment header page of system tablespace for the slots 1..127 3) Update the binlog and WSREP information in system tablespace rollback segment header Step (1), (2) and Step (3) should happen atomically within a single mini-transaction. 4) srv_undo_delete_old_tablespaces(): Delete the old undo tablespaces present in the undo log directory 5) Make checkpoint to get rid of old undo log tablespaces redo logs 6) Assign new start space id for the undo log tablespaces 7) Re-create the specified undo log tablespaces. InnoDB uses same mtr for this one and step (6) 8) Make checkpoint again, so that server or mariabackup can read the undo log tablespace page0 before applying the redo logs srv_undo_tablespaces_reinit(): Recreate the undo log tablespaces. It does reset trx_sys page, delete the old undo tablespaces, update the binlog offset, write set replication checkpoint in system rollback segment page trx_rseg_update_binlog_offset(): Added 2 new parameters to pass binlog file name and binlog offset trx_rseg_array_init(): Return error if the rollback segment slot points to non-existent tablespace srv_undo_tablespaces_init(): Added new parameter mtr to initialize all undo tablespaces trx_assign_rseg_low(): Allow the transaction to use the rollback segment slots(1..127) even if InnoDB failed to change to the requested innodb_undo_tablespaces=0 srv_start(): Override the user specified value of innodb_undo_tablespaces variable with already existing actual undo tablespaces wf_incremental_process(): Detects whether TRX_SYS page has been modified since last backup. If it is then incremental backup fails and throws the information about taking full backup again xb_assign_undo_space_start(): Removed the function. Because undo001 has first undo space id value in page0 Added test case to test the scenario during startup and mariabackup incremental process too. Reviewed-by : Marko Mäkelä Tested-by : Matthias Leich

Author: Thirunarayanan

extra/mariabackup/write_filt.cc

@@ -129,6 +129,18 @@ wf_incremental_process(xb_write_filt_ctxt_t *ctxt, ds_file_t *dstfile)
 incremental_lsn >= mach_read_from_8(page + FIL_PAGE_LSN))
 continue;
 
+/* Check whether TRX_SYS page has been changed */
+if (mach_read_from_4(page + FIL_PAGE_SPACE_ID)
+== TRX_SYS_SPACE
+ && mach_read_from_4(page + FIL_PAGE_OFFSET)
+== TRX_SYS_PAGE_NO) {
+msg(cursor->thread_n,
+ "--incremental backup is impossible if "
+ "the server had been restarted with "
+ "different innodb_undo_tablespaces.");
+return false;
+}
+
 /* updated page */
 if (cp->npages == page_size / 4) {
 /* flush buffer */

extra/mariabackup/xtrabackup.cc

@@ -3826,89 +3826,6 @@ static dberr_t enumerate_ibd_files(process_single_tablespace_func_t callback)
 return(err);
 }
 
-/** Assign srv_undo_space_id_start variable if there are undo tablespace present.
-Read the TRX_SYS page from ibdata1 file and get the minimum space id from
-the first slot rollback segments of TRX_SYS_PAGE_NO.
-@retval DB_ERROR if file open or page read failed.
-@retval DB_SUCCESS if srv_undo_space_id assigned successfully. */
-static dberr_t xb_assign_undo_space_start()
-{
-
-pfs_os_file_tfile;
-boolret;
-dberr_terror = DB_SUCCESS;
-uint32_tspace;
-uint32_t	fsp_flags;
-intn_retries = 5;
-
-if (srv_undo_tablespaces == 0) {
-return error;
-}
-
-file = os_file_create(0, srv_sys_space.first_datafile()->filepath(),
-OS_FILE_OPEN, OS_FILE_NORMAL, OS_DATA_FILE, true, &ret);
-
-if (!ret) {
-msg("Error opening %s", srv_sys_space.first_datafile()->filepath());
-return DB_ERROR;
-}
-
-byte* page = static_cast<byte*>
-(aligned_malloc(srv_page_size, srv_page_size));
-
-if (os_file_read(IORequestRead, file, page, 0, srv_page_size)
- != DB_SUCCESS) {
-msg("Reading first page failed.\n");
-error = DB_ERROR;
-goto func_exit;
-}
-
-fsp_flags = mach_read_from_4(
-page + FSP_HEADER_OFFSET + FSP_SPACE_FLAGS);
-retry:
-if (os_file_read(IORequestRead, file, page,
- TRX_SYS_PAGE_NO << srv_page_size_shift,
- srv_page_size) != DB_SUCCESS) {
-msg("Reading TRX_SYS page failed.");
-error = DB_ERROR;
-goto func_exit;
-}
-
-/* TRX_SYS page can't be compressed or encrypted. */
-if (buf_page_is_corrupted(false, page, fsp_flags)) {
-if (n_retries--) {
-std::this_thread::sleep_for(
-std::chrono::milliseconds(1));
-goto retry;
-} else {
-msg("mariabackup: TRX_SYS page corrupted.\n");
-error = DB_ERROR;
-goto func_exit;
-}
-}
-
-/* 0th slot always points to system tablespace.
-1st slot should point to first undotablespace which is minimum. */
-
-ut_ad(mach_read_from_4(TRX_SYS + TRX_SYS_RSEGS
- + TRX_SYS_RSEG_SLOT_SIZE
- + TRX_SYS_RSEG_PAGE_NO + page)
- != FIL_NULL);
-
-space = mach_read_from_4(TRX_SYS + TRX_SYS_RSEGS
- + TRX_SYS_RSEG_SLOT_SIZE
- + TRX_SYS_RSEG_SPACE + page);
-
-srv_undo_space_id_start = space;
-
-func_exit:
-aligned_free(page);
-ret = os_file_close(file);
-ut_a(ret);
-
-return error;
-}
-
 /****************************************************************************
 Populates the tablespace memory cache by scanning for and opening data files.
 @returns DB_SUCCESS or error code.*/
@@ -3946,14 +3863,7 @@ xb_load_tablespaces()
 }
 
 /* Add separate undo tablespaces to fil_system */
-
-err = xb_assign_undo_space_start();
-
-if (err != DB_SUCCESS) {
-return err;
-}
-
-err = srv_undo_tablespaces_init(false);
+err = srv_undo_tablespaces_init(false, nullptr);
 
 if (err != DB_SUCCESS) {
 return(err);

mysql-test/suite/innodb/include/have_undo_tablespaces.inc

@@ -184,7 +184,7 @@ SELECT * FROM INFORMATION_SCHEMA.ENGINES
 WHERE engine = 'innodb'
 AND support IN ('YES', 'DEFAULT', 'ENABLED');
 ENGINE	SUPPORT	COMMENT	TRANSACTIONS	XA	SAVEPOINTS
-FOUND 1 /InnoDB: Expected to open innodb_undo_tablespaces=3 but was able to find only 1/ in mysqld.1.err
+FOUND 1 /InnoDB: Failed to open the undo tablespace/ in mysqld.1.err
 bak_ib_logfile0
 bak_ibdata1
 bak_ibdata2
@@ -214,7 +214,7 @@ SELECT * FROM INFORMATION_SCHEMA.ENGINES
 WHERE engine = 'innodb'
 AND support IN ('YES', 'DEFAULT', 'ENABLED');
 ENGINE	SUPPORT	COMMENT	TRANSACTIONS	XA	SAVEPOINTS
-FOUND 1 /InnoDB: Expected to open innodb_undo_tablespaces=3 but was able to find only 0/ in mysqld.1.err
+FOUND 2 /InnoDB: Failed to open the undo tablespace/ in mysqld.1.err
 bak_ib_logfile0
 bak_ibdata1
 bak_ibdata2

mysql-test/suite/innodb/r/log_file.result

@@ -1,3 +1,5 @@
+SET GLOBAL innodb_fast_shutdown=0;
+# restart: --innodb_undo_tablespaces=2
 SET GLOBAL innodb_undo_log_truncate = 0;
 SET GLOBAL innodb_purge_rseg_truncate_frequency = 1;
 create table t1(keyc int primary key, c char(100)) engine = innodb;

mysql-test/suite/innodb/r/undo_truncate.result

@@ -1,3 +1,5 @@
+SET GLOBAL innodb_fast_shutdown=0;
+# restart: --innodb_undo_tablespaces=2
 SET GLOBAL innodb_undo_log_truncate = 1;
 SET GLOBAL innodb_purge_rseg_truncate_frequency = 1;
 create table t1(keyc int primary key, c char(100)) engine = innodb;

mysql-test/suite/innodb/r/undo_truncate_recover.result

@@ -0,0 +1,80 @@
+#
+# MDEV-19229 Allow innodb_undo_tablespaces to be changed
+#	after database creation
+#
+call mtr.add_suppression("Found .* prepared XA transactions");
+call mtr.add_suppression("InnoDB: Plugin initialization aborted");
+call mtr.add_suppression("Plugin 'InnoDB' init function returned error");
+call mtr.add_suppression("Plugin 'InnoDB' registration as a STORAGE ENGINE failed");
+call mtr.add_suppression("InnoDB: Cannot change innodb_undo_tablespaces=\\d+ because previous shutdown was not with innodb_fast_shutdown=0");
+CREATE TABLE t1(f1 INT NOT NULL)ENGINE=InnoDB;
+connect con_purge,localhost,root,,,;
+START TRANSACTION WITH CONSISTENT SNAPSHOT;
+connection default;
+INSERT INTO t1 VALUES(1);
+UPDATE t1 SET f1=100;
+# case 1: Undo log left to purge
+# restart: --innodb_undo_tablespaces=2
+# Display 4 undo tablespaces
+select @@global.innodb_undo_tablespaces;
+@@global.innodb_undo_tablespaces
+4
+# Should list 4 undo log tablespaces
+undo001
+undo002
+undo003
+undo004
+# case 2: XA transaction alone left
+InnoDB	0 transactions not purged
+XA START 'zombie';
+INSERT INTO t1 VALUES(2);
+XA END 'zombie';
+XA PREPARE 'zombie';
+# restart: --innodb_undo_tablespaces=2
+# Display 4 undo tablespaces
+select @@global.innodb_undo_tablespaces;
+@@global.innodb_undo_tablespaces
+4
+# Should list 4 undo log tablespaces
+undo001
+undo002
+undo003
+undo004
+XA COMMIT 'zombie';
+# case 3: Successful innodb_undo_tablespace upgrade
+SET GLOBAL innodb_fast_shutdown=0;
+# restart: --innodb_undo_tablespaces=2
+# Display 2 undo tablespaces
+SELECT @@global.innodb_undo_tablespaces;
+@@global.innodb_undo_tablespaces
+2
+# Should list 2 undo log tablespaces
+undo001
+undo002
+DROP TABLE t1;
+InnoDB	0 transactions not purged
+# case 4: Reduce the innodb_undo_tablespace to 0
+# restart: --innodb_undo_tablespaces=0
+# Display 0 undo tablespace
+SELECT @@global.innodb_undo_tablespaces;
+@@global.innodb_undo_tablespaces
+0
+# Shouldn't list any undo log tablespaces
+# case 5: Change undo tablespace when force_recovery < 5
+# restart: --innodb_undo_tablespaces=2 --innodb_force_recovery=4
+# Display 2 undo tablespace
+SELECT @@global.innodb_undo_tablespaces;
+@@global.innodb_undo_tablespaces
+2
+# Should list 2 undo log tablespaces
+undo001
+undo002
+# case 6: Fail to change undo tablespace when force_recovery > 4
+# restart: --innodb_undo_tablespaces=4 --innodb_force_recovery=5
+# Display 2 undo tablespace
+SELECT @@global.innodb_undo_tablespaces;
+@@global.innodb_undo_tablespaces
+2
+# Should list 2 undo log tablespaces, not 4
+undo001
+undo002

mysql-test/suite/innodb/r/undo_upgrade.result

@@ -0,0 +1,43 @@
+#
+# MDEV-19229 Allow innodb_undo_tablespaces to be changed
+# after database creation
+#
+call mtr.add_suppression("InnoDB: Plugin initialization aborted");
+call mtr.add_suppression("Plugin 'InnoDB' init function returned error");
+call mtr.add_suppression("Plugin 'InnoDB' registration as a STORAGE ENGINE failed");
+set global innodb_fast_shutdown=0;
+# case 1: Abort after resetting TRX_SYS page rollback segments
+# restart: --innodb_undo_tablespaces=4 --debug_dbug=+d,after_rseg_reset_abort
+# restart: --innodb_undo_tablespaces=4
+# Should list 4 undo log tablespaces
+undo001
+undo002
+undo003
+undo004
+# case 2: Abort after deleting the old undo tablespaces
+# restart: --innodb_undo_tablespaces=2 --debug_dbug=+d,after_deleting_old_undo_abort
+# restart: --innodb_undo_tablespaces=2
+# Should list 2 undo log tablespaces
+undo001
+undo002
+# case 3: Abort after successfully deleting the old undo tablespace
+# restart: --innodb_undo_tablespaces=3 --debug_dbug=+d,after_deleting_old_undo_success
+# restart: --innodb_undo_tablespaces=3
+# Should list 3 undo log tablespaces
+undo001
+undo002
+undo003
+# case 4: Abort after re-creating new undo tablespaces
+# restart: --innodb_undo_tablespaces=4 --debug_dbug=+d,after_reinit_undo_abort
+# restart: --innodb_undo_tablespaces=4
+# Should list 4 undo log tablespaces
+undo001
+undo002
+undo003
+undo004
+# case 5: Abort after re-creating new undo tablespaces successfully
+# restart: --innodb_undo_tablespaces=2 --debug_dbug=+d,after_reinit_undo_success
+# restart: --innodb_undo_tablespaces=2
+# Should list 2 undo log tablespaces
+undo001
+undo002

mysql-test/suite/innodb/r/undo_upgrade_debug.result

@@ -164,7 +164,7 @@ let SEARCH_PATTERN=undo tablespace .*undo003.* exists\. Creating system tablespa
 --source include/start_mysqld.inc
 eval $check_no_innodb;
 --source include/shutdown_mysqld.inc
-let SEARCH_PATTERN=InnoDB: Expected to open innodb_undo_tablespaces=3 but was able to find only 1;
+let SEARCH_PATTERN=InnoDB: Failed to open the undo tablespace;
 --source include/search_pattern_in_file.inc
 # clean up & Restore
 --source ../include/log_file_cleanup.inc
@@ -176,7 +176,7 @@ let SEARCH_PATTERN=InnoDB: Expected to open innodb_undo_tablespaces=3 but was ab
 --source include/start_mysqld.inc
 eval $check_no_innodb;
 --source include/shutdown_mysqld.inc
-let SEARCH_PATTERN=InnoDB: Expected to open innodb_undo_tablespaces=3 but was able to find only 0;
+let SEARCH_PATTERN=InnoDB: Failed to open the undo tablespace;
 --source include/search_pattern_in_file.inc
 
 # clean up & Restore

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

@@ -1,6 +1,5 @@
 --source include/have_innodb.inc
 --source include/innodb_page_size.inc
---source include/have_undo_tablespaces.inc
 --source include/not_embedded.inc
 --source include/have_sequence.inc
 --source include/no_valgrind_without_big.inc
@@ -12,6 +11,11 @@ call mtr.add_suppression("InnoDB: Difficult to find free blocks in the buffer po
 call mtr.add_suppression("InnoDB: Trying to delete tablespace.*pending operations");
 --enable_query_log
 
+# Re-create the undo log tablespaces after slow shutdown
+SET GLOBAL innodb_fast_shutdown=0;
+let $restart_parameters="--innodb_undo_tablespaces=2";
+--source include/restart_mysqld.inc
+
 SET GLOBAL innodb_undo_log_truncate = 0;
 SET GLOBAL innodb_purge_rseg_truncate_frequency = 1;
 
@@ -53,6 +57,7 @@ let $trx_before= `select substr('$trx_before',9)+2`;
 SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
 SET GLOBAL innodb_max_purge_lag_wait=0;
 set global innodb_fast_shutdown=0;
+let $restart_parameters=;
 --source include/restart_mysqld.inc
 --replace_regex /.*Trx id counter ([0-9]+).*/\1/
 let $trx_after= `SHOW ENGINE INNODB STATUS`;