… MyISAM you’ll have to start the snapshot while holding a “flush tables with read lock” and the flush operation will take some time to… data will compress much more. That gives us much more disk space than we expected so even more snapshots! Integrity With… from the other drive in the mirror. Better availability and disk usage On purpose, I allocated mirror pairs using drives from…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
…) and a 4GiB buffer pool. The cache devices were flushed to disk immediately prior to and immediately following each test run. With that out…-based flushing allows the backing store to be written to at a more constant and, potentially, submaximal, rate compared to dirty-page-threshold flushing, which…_size = 4M bulk_insert_buffer_size = 8M myisam_sort_buffer_size = 8M myisam_max_sort_file_size = 10G myisam_repair_threads = 1 myisam_recover
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
… to 18000 tps, but InnoDB can’t make 5h run. After 3h the disk is…data/mysql #for SSD innodb_flush_neighbor_pages = none innodb_adaptive_flushing_method = keep_average …myisam_sort_buffer_size = 8M myisam_max_sort_file_size = 10G #myisam_max_extra_sort_file_size = 10G myisam_repair_threads = 1 myisam…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 118 Comments
… values. innodb_flush_log_at_trx_commit Crying about Innodb being 100 times slower than MyISAM ? You probably forgot to adjust this value… those moved from MyISAM tables are OK with value 2 which means do not flush log to the disk but only flush it to OS cache. The log is still flushed to the disk each second so you…
Post: How fast is FLUSH TABLES WITH READ LOCK?
April 24, 2010 By 30 Comments
…, MyISAM does not attempt to flush its own data to the disk during normal processing. It relies on the operating system to flush the data blocks to disk when it decides to. As a result, a system that has a lot of MyISAM data might…
Comment: How fast is FLUSH TABLES WITH READ LOCK?
February 24, 2012 By 30 Comments
… really a way to take online backups of MyISAM tables without issuing FLUSH TABLES WITH READ LOCK command and/or setting flush_time (performance…’t clear about data being flushed to disk 100% ie. leaving the OS buffers and getting flushed to disk after the FLUSH TABLES WITH READ LOCK command…
Post: Using MyISAM in production
June 17, 2006 By 36 Comments
… from “traditional” databases you’re likely to be shocked by MyISAM behavior (and default MySQL behavior due to this) – it will be corrupted… can happen concurrently to select statements but it has to be one insert at the time. Happily inserts in MyISAM are rather fast… performance dramatically in certain cases by avoiding flushing dirty index blocks from key_buffer to disk, but it also comes at great danger…
Post: A recovery trivia or how to recover from a lost ibdata1 file
June 3, 2011 By 8 Comments
…, also for portability, to do “alter table tablename engine=MyISAM;” Script all that In order to get a decent disk space and good internet… tablespace;” sleep 1 echo “switching to MyISAM” mysql -u root -e “alter table recover.$CURRENT_TABLENAME engine=MyISAM;flush tables;” sleep 1 let CURRENT…
Post: Redis Benchmarks on FusionIO (Round 1)
December 10, 2009 By 7 Comments
… be written to disk during the tests. 2 – Semi-Persistent I set “save 1 1″ so that changes would be flushed to disk every second… yes and appendfsync no, which is about as persistent as MyISAM. An fsync is never explicitly called, rather we’re relying… was 1.9M. If you’re going to to use appendonly in production, be sure to consider the additional storage requirements. – In every…
Post: MongoDB Approach to Availability
April 30, 2010 By 2 Comments
… as commit to NDB Storage engine does not normally mean commit to disk, but rather commit to network it does not mean commit to disk with… innodb_flush_log_at_trx_commit=2 mode. The second difference of course the fact MongoDB is not crash safe – similar to MyISAM database will need to be repaired if it crashes. Still I find behavior somewhat similar – you’re not expected to run…
