… master shutdown: 080603 20:53:10 [Note] Slave I/O thread: Failed reading log event, reconnecting to retry, … would explain what is wrong. In fact the issue in this case is (because of configuration error)… for this error message which MySQL already does in many other cases. I‘ve now filed it as…
Post: Replication checksums in MySQL 5.6
February 15, 2013 By 3 Comments
…I mentioned above are not the only ones that can break data integrity. One fairly common issue… command SHOW BINLOG EVENTS: Wrong offset or I/O error But on slaves, the corruption will…mysql-bin.000001′ at 2793, the last event read from ‘./mysql-bin.000001′ at 2793, the last byte read from ‘./mysql…
Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
…_at_trx_commit=2 innodb_doublewrite=1 innodb_flush_method=O_DIRECT innodb_max_dirty_pages_pct=80 innodb_file_format… one in Percona Server 5.1. MySQL 5.6.2 multiple purge threads have major issues and just removing the purge sleeps is not enough to solve them. However, MySQL 5.6.2 is experimental code and I…
Post: Filling the tmp partition with persistent connections
August 6, 2012 By 14 Comments
…, which would defeat the performance improvement as it uses disk I/O anyway. Ramfs will not swap, and also ramfs will grow… physical memory, most likely killing system in the end. Conclusion MySQL can creates temporary files even thought those temporary files are… help you avoid these situations. I‘ve opened a bug report to follow this issue: http://bugs.mysql.com/bug.php?id=66237
Post: MySQL 5.6: Improvements in the Nutshell
January 27, 2013 By 16 Comments
…MySQL University in Raleigh,NC, Tuesday 29th of January I have created the outline of improvements available in MySQL 5.6 which I…Coherence and False Sharing issues – Reduced Innodb Memory Fragmentation -…- Show Host Cache Contents – - Improved File I/O Instrumentation – Improved EXPLAIN – - Explain …
Post: Living with backups
November 6, 2008 By 28 Comments
… be read, through I/O requests, from a storage that it resides on. The storage is handling reads issued by the system, but… pattern may be preferred by the I/O scheduler over random I/O coming from MySQL, but also such large I/O requests take significant time to… MySQL data files do not comply with this requirement. The trick could be used here perhaps to read the file with O…
Post: Can Innodb Read-Ahead reduce read performance ?
June 26, 2007 By 2 Comments
…I/O ——– I/O thread 0 state: waiting for i/o request (insert buffer thread) I/O thread 1 state: waiting for i/o request (log thread) I/O…I‘m using “seems” as there are no detailed enough stats available) is once thread has issued… was doing (I was adviseor in this project from MySQL AB side) – …
Comment: Benchmarks of new innodb_flush_neighbor_pages
July 3, 2012 By 8 Comments
… still I went here to check out the improvements in mysql 5.6 http://dev.mysql.com/tech-resources/articles/whats-new-in-mysql-5.6.html These improvements sound interesting to page flush and i/o problems… and stalls/lockups, even though the lock issue might be solved for this I still think the idea can be used to…
Comment: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
August 11, 2011 By 13 Comments
I faced a purge issue causing huge I/O activity on our poor hardware (RAID 5) but strangley I tried all possible combinations of max… load an MySQL kept on doing the background I/O work causing problems for us today is this a know issue in MySQL 5.0…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…>= 30 should be better than 4.1.xx. PZ: I should note MySQL 5.0 vs 4.1 has a lot of…Innodb in 5.0 series. Also note the “Auto Increment Issue” is finally solved in 5.1 which may be even…performance for full table scans. using O_DIRECT, we are seeing individual 16KB paged I/O going out one at a time, …
