…: —TRANSACTION 72C, ACTIVE 755 sec 4 lock struct(s), heap size 1248, 3 row lock(s), undo log entries 1 MySQL thread id 3, OS thread handle 0x7f84a78ba700, query id 163 localhost msandbox TABLE LOCK table `test`.`t` trx id 72C…` trx id 72C lock_mode X locks gap before rec If you have lot of gaps locks in your transactions affecting the…
Comment: Emulating global transaction ID with pt-heartbeat
April 24, 2012 By 6 Comments
… master and knowing that mysql does not have a way match the transactions as ‘global transactions id‘.I agree that matching logs is very tedious… captured information is telling that B ( relay_master_log_file: test_file , exec_master_log_pos: 2399 ) was replicating from these positions…
Post: Emulating global transaction ID with pt-heartbeat
November 4, 2011 By 6 Comments
Global transaction IDs are being considered for a future version of MySQL. A global transaction ID lets you determine a server’s replication position reliably… replication heartbeat record on C actually said approximately which binary log and byte offset to look in? That would have saved…
Post: MVCC: Transaction IDs, Log Sequence numbers and Snapshots
December 19, 2007 By 3 Comments
MySQL Storage Engines implementing Multi Version…understand MVCC a bit better. Transaction ID As the name says this is transaction identifier. It can be …transactions – changes from different transactions are intermixed in the log files and many LSNs can correspond to changes from the same transaction…
Post: How InnoDB handles REDO logging
February 3, 2011 By 18 Comments
… that affects both response time and throughput – The transaction log. The InnoDB transaction log handles REDO logging, this is the mechanism that provides the A… in (D)urable memory and that each transaction is (A)tomic. What is actually logged?
Post: Can MySQL temporary tables be made safe for statement-based replication?
May 26, 2008 By 8 Comments
…=InnoDB, and the InnoDB transaction ID does not change in SHOW INNODB STATUS. The statements are all within one transaction. (However, if you…_Log_File: mysql-bin.000006 Read_Master_Log_Pos: 98 Relay_Log_File: mysql_sandbox20551-relay-bin.000028 Relay_Log_Pos: 235 Relay_Master_Log_File: mysql-bin…
Post: Using Flexviews - part two, change data capture
March 25, 2011 By 11 Comments
… name. The Binary Log is the MySQL log which records changes to tables in the database. FlexCDC reads the binary log to determine what… based logging (binlog_format=1) unique server_id in the my.cnf log_slave_updates=1, if this is a MySQL slave transaction_isolation=READ… Duplicates: 0 Warnings: 0 And delete data in a second transaction: mysql> delete from test.demo where c1=1; Query OK, 1…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
…. The incremental method is somewhat conceptually similar to using mysql binary logs for point-in-time recovery after a restoring a backup…’ or ‘APPLY’ changes to a particular transaction id. Logically, you can not apply changes past the transaction id to which you have computed them. And then confirm they contain the same results mysql> select sum(total…
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
… query log, and examine the log. In MySQL 5.1 and newer with the InnoDB plugin, it’s easy to figure out which transaction… ON b.trx_id = w.blocking_trx_id INNER JOIN information_schema.processlist p on b.trx_mysql_thread_id = p.ID LIMIT 1′) if… even with full server logging. There was a transaction that was blocking others and had locks and undo log records, yet had only…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL…transaction_alloc_block_sizeblogpercona.commanual transaction_isolationblogpercona.commanual transaction…
