pt-table-checksum檢測不出主從差異處理
阿新 • • 發佈：2018-05-08
ola ble 發布 crash recursion log ext open png 
幾個月前寫過pt-table-checksum 3.0.4檢測不出主從差異數據，當時的解決方案是使用舊版本，另一個挫方法是自行設置binlog_format=‘STATEMENT‘。現在已經發布到3.0.9版本，原以為官方修復那個問題，結果還是一樣的坑~
最近幾版pt-table-checksum在binlog_format=‘row‘，且主從存在差異數據時，卻檢測不出主從差異。原因就是主上沒有SET @@binlog_format := ‘STATEMENT‘，導致下面兩個核心語句不是以statement格式記錄，從庫不會進行CRC32相關運算，主從永遠一致~
# pt-table-checksum 3.0View Code.4檢測不出差異數據 [root@ZST2 ~]# /usr/local/bin/pt-table-checksum --nocheck-binlog-format --nocheck-replication-filters --recursion-method=hosts --replicate=replcrash.checksums --databases=replcrash --tables=py_user,py_user_innodb --host=192.168.85.132 --port=3306 --user=mydba --password=mysql5721 TS ERRORS DIFFS ROWS CHUNKS SKIPPED TIME TABLE05-08T09:41:15 0 0 8 1 0 0.257 replcrash.py_user 05-08T09:41:16 0 0 67740 5 0 1.056 replcrash.py_user_innodb # 兩個核心語句 REPLACE INTO `replcrash`.`checksums` (db, tbl, chunk, chunk_index, lower_boundary, upper_boundary, this_cnt, this_crc) SELECT ‘replcrash‘, ‘py_user‘, ‘1‘, NULL, NULL, NULL, COUNT(*) AS cnt, COALESCE(LOWER(CONV(BIT_XOR(CAST(CRC32(CONCAT_WS(‘#‘, `uid`, convert(`name` using utf8mb4), `add_time`, convert(`server_id` using utf8mb4), CONCAT(ISNULL(`name`), ISNULL(`add_time`), ISNULL(`server_id`)))) AS UNSIGNED)), 10, 16)), 0) AS crc FROM `replcrash`.`py_user` /*checksum table*/ UPDATE `replcrash`.`checksums` SET chunk_time = ‘0.004092‘, master_crc = ‘5abbd632‘, master_cnt = ‘8‘ WHERE db = ‘replcrash‘ AND tbl = ‘py_user‘ AND chunk = ‘1‘
通過對比舊版本(2.2.3)的/usr/local/bin/pt-table-checksum代碼，發現只需稍微調整代碼即可正常使用
# pt-table-checksum 3.0.4 只需註釋掉第9335行和9364行，這層邏輯應該應用於任何情況下，因此不需要使用if判斷 [root@ZST2 ~]# vim /usr/local/bin/pt-table-checksum ... 9335 #if ( $o->get(‘check-binlog-format‘) ) { 9336 # https://bugs.launchpad.net/percona-toolkit/+bug/919352 9337 # The tool shouldn‘t blindly attempt to change binlog_format; 9338 # instead, it should check if it‘s already set to STATEMENT. 9339 # This is becase starting with MySQL 5.1.29, changing the format 9340 # requires a SUPER user. 9341 if ( VersionParser->new($dbh) >= ‘5.1.5‘ ) { 9342 $sql = ‘SELECT @@binlog_format‘; 9343 PTDEBUG && _d($dbh, $sql); 9344 my ($original_binlog_format) = $dbh->selectrow_array($sql); 9345 PTDEBUG && _d(‘Original binlog_format:‘, $original_binlog_format); 9346 if ( $original_binlog_format !~ /STATEMENT/i ) { 9347 $sql = q{/*!50108 SET @@binlog_format := ‘STATEMENT‘*/}; 9348 eval { 9349 PTDEBUG && _d($dbh, $sql); 9350 $dbh->do($sql); 9351 }; 9352 if ( $EVAL_ERROR ) { 9353 die "Failed to $sql: $EVAL_ERROR\n" 9354 . "This tool requires binlog_format=STATEMENT, " 9355 . "but the current binlog_format is set to " 9356 ."$original_binlog_format and an error occurred while " 9357 . "attempting to change it. If running MySQL 5.1.29 or newer, " 9358 . "setting binlog_format requires the SUPER privilege. " 9359 . "You will need to manually set binlog_format to ‘STATEMENT‘ " 9360 . "before running this tool.\n"; 9361 } 9362 } 9363 } 9364 #} ... # 查看pt版本 [root@ZST2 ~]# /usr/local/bin/pt-table-checksum --version pt-table-checksum 3.0.4 [root@ZST2 ~]# # 修改後檢測出主從不一致 [root@ZST2 ~]# /usr/local/bin/pt-table-checksum --nocheck-binlog-format --nocheck-replication-filters --recursion-method=hosts --replicate=replcrash.checksums --databases=replcrash --tables=py_user,py_user_innodb --host=192.168.85.132 --port=3306 --user=mydba --password=mysql5721 TS ERRORS DIFFS ROWS CHUNKS SKIPPED TIME TABLE 05-08T09:51:32 0 1 8 1 0 0.030 replcrash.py_user 05-08T09:51:33 0 0 67740 5 0 0.561 replcrash.py_user_innodb [root@ZST2 ~]# # general-log信息 [root@ZST1 ~]# cat /data/mysql/mysql3306/data/ZST1.log |more ... 2018-05-08T01:51:32.315064Z 30 Query SHOW VARIABLES LIKE ‘version%‘ 2018-05-08T01:51:32.318337Z 30 Query SHOW ENGINES 2018-05-08T01:51:32.319229Z 30 Query SHOW VARIABLES LIKE ‘innodb_version‘ 2018-05-08T01:51:32.322518Z 30 Query SELECT @@binlog_format 2018-05-08T01:51:32.323019Z 30 Query /*!50108 SET @@binlog_format := ‘STATEMENT‘*/ 2018-05-08T01:51:32.323453Z 30 Query SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ 2018-05-08T01:51:32.324012Z 30 Query SHOW VARIABLES LIKE ‘wsrep_on‘ 2018-05-08T01:51:32.327830Z 30 Query SELECT @@SERVER_ID 2018-05-08T01:51:32.328416Z 30 Query SHOW SLAVE HOSTS 2018-05-08T01:51:32.344178Z 30 Query SHOW VARIABLES LIKE ‘wsrep_on‘ 2018-05-08T01:51:32.347571Z 30 Query SELECT @@SERVER_ID 2018-05-08T01:51:32.351692Z 30 Query SHOW VARIABLES LIKE ‘wsrep_on‘ 2018-05-08T01:51:32.355034Z 30 Query SELECT @@SERVER_ID 2018-05-08T01:51:32.359543Z 30 Query SHOW DATABASES LIKE ‘replcrash‘ 2018-05-08T01:51:32.360406Z 30 Query CREATE DATABASE IF NOT EXISTS `replcrash` /* pt-table-checksum */ 2018-05-08T01:51:32.361538Z 30 Query USE `replcrash` 2018-05-08T01:51:32.362069Z 30 Query SHOW TABLES FROM `replcrash` LIKE ‘checksums‘ 2018-05-08T01:51:32.364738Z 30 Query CREATE TABLE IF NOT EXISTS `replcrash`.`checksums` ( db CHAR(64) NOT NULL, tbl CHAR(64) NOT NULL, chunk INT NOT NULL, chunk_time FLOAT NULL, chunk_index VARCHAR(200) NULL, lower_boundary TEXT NULL, upper_boundary TEXT NULL, this_crc CHAR(40) NOT NULL, this_cnt INT NOT NULL, master_crc CHAR(40) NULL, master_cnt INT NULL, ts TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (db, tbl, chunk), INDEX ts_db_tbl (ts, db, tbl) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 2018-05-08T01:51:32.920625Z 30 Query SHOW GLOBAL STATUS LIKE ‘Threads_running‘ 2018-05-08T01:51:32.924636Z 30 Query SELECT CONCAT(@@hostname, @@port) ...View Code
如果遇到類似問題，建議開啟general_log，查看處理過程，再核驗到底什麽原因導致檢測不出主從差異數據(?ω?)
pt-table-checksum檢測不出主從差異處理