… user experience to degrade. The first thing you need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries… does not overload the system. Unless it is really time critical process I would not use more than 4 parallel processes heavily writing to database…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…uses MySQL to identify potential causes. Is it working with large blobs ? Using…Database pages 8252672 Old database pages 3046376 Modified db pages 23419 I’m using…
Post: Testing Samsung SSD SATA 256GB 830 - not all SSD created equal
April 25, 2012 By 10 Comments
… I switched to use async IO mode. There are two reasons for that. First, MySQL/InnoDB uses async writes, so this will emulate database load, and second, async mode allows to see maximal possible throughput, it does not show…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… tools used by mysql client, so you might get a feel you can’t connect to the database at all (use mysql -A in this case, to prevent it from getting field list from all tables) Reads though would not… I’d love to see this problem fixed. There is no reason (other than code design) for read lock to wait for other…
Post: Testing STEC SSD MACH16 200GB SLC
April 25, 2012 By 7 Comments
… I switched to use async IO mode. There are two reasons for that. First, MySQL/InnoDB uses async writes, so this will emulate database load, and second, async mode allows to see maximal possible throughput, it does not show…
Post: Upgrading MySQL
January 5, 2010 By 23 Comments
…use mk-query-digest with tcpdump to sniff out queries if you can’t enable log for any reason). As you’ve gotten database…to use MySQL Replication for upgrade. Once you have setup slave with new version and made it to caught up you can use…
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
…MySQL handles connections, allocating one thread per connection to the server. MySQL is a single process with multiple threads. Not all databases…reasons that this matters — please fill in whatever’s missing in the comments. There can be more than one solution to…
Post: What's the recommended MySQL version?
August 15, 2011 By 24 Comments
… distinguisher). For an existing MySQL database server, I’d encourage not jumping on a new …reason is that I like to keep the upgrade cycle as long as possible, and if you’re going to…use MySQL 5.6. For older applications running MySQL 5.0, I’d say upgrade to 5.5 directly, skipping over 5.1. MySQL…
Post: How to recover a single InnoDB table from a Full Backup
January 25, 2012 By 7 Comments
…’s stock MySQL you cannot move your ibd files freely from one server to another or from one database to another. The reason is that… order to not be dependent of the shared tablespace ibdata. That is, shutting down with innodb_fast_shutdown=0. We’ll use XtraBackup to…: mysql> set FOREIGN_KEY_CHECKS=0; mysql> ALTER TABLE salaries DISCARD TABLESPACE; Copy the salaries.ibd files from the backup to the database data…
Post: Logging MySQL queries from the client instead of the server
February 2, 2011 By 2 Comments
… way to examine query execution on your MySQL …to. Another reason for logging from the client is to…to a database table and then use SQL to analyze the queries; but this is quite a bit harder, because similar queries need to…not log everything, such as superfluous ‘ping’ commands. Another option is to…
