… assume that the [read|write] of a single word from memory is atomic */. While …read this same variable, they will get an old value for quite some time after the…show_status_array(THD*, char const*, st_mysql_show_var*, enum_var_type, system_status_var*, char const*, st_table*, bool, Item*) (sql_show…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 8 Comments
…-memory plugin checks for a single process consuming too much … one-size-fits-all value. This plugin, perhaps more than…mysql-status is also very flexible and can be used to trigger an alert on almost anything from SHOW VARIABLES and SHOW STATUS…so you can (for example) get the incremental increase in …
Post: How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
…get right. I estimate that about 80% of the cases I work on show up as abnormally high values… you can observe (such as SHOW STATUS snapshots) and establish both baseline… on the same data. No single tool, no matter how powerful…stall in MySQL, and they usually begin microscopically and get worse over …
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… itself is generally a single person, with another … Looking at MySQL status Now we’re starting to get into …status values for Created_tmp_tables and Created_disk_tmp_tables, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…MySQL 5 number of Innodb performance counters were exported and now available in SHOW STATUS…SHOW INNODB STATUS, there are however few which were not available before. In SHOW INNODB STATUS many values…SHOW INNODB STATUS it is much better to use global counters and get… and single page – independent…
Post: MySQL performance on EC2/EBS versus RDS
August 4, 2011 By 10 Comments
… InnoDB, or to the Threads_running SHOW STATUS counter, without much loss of generality. …MySQL 5.1, EC2, and a 10-volume EBS RAID. However, I was able to get… Amazon cloud platform, bigger than a single instance can hold or with more write…, and it’s not a bad value for the money compared to building …
Post: How much space does empty Innodb table take ?
December 16, 2008 By 7 Comments
…—- 1 mysql mysql 98304 Dec 16 20:33 test_innodb.ibd So we get …which may need an explanation. This value is computed by dividing Data_Length … will show 16K as average row size for table with one row: mysql> show table status …allocated. In the case above no single segment should require more than …
Post: Different flavors of InnoDB flushing
January 13, 2011 By 9 Comments
…values for innodb_buffer_pool_size, like 13GB, 52GB, and 144GB, for testing the tpcc-mysql…SHOW ENGINE INNODB STATUS: … Pending writes: LRU 0, flush list 129, single… MySQL 5.5 to get stable…mysql-55.html). But you can’t really detect what kind of flushing is used. There is a variable in SHOW STATUS…
Post: The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 5 Comments
…mysql> SHOW ENGINE INNODB STATUS\G — LOG — Log sequence number 9682004056 Log flushed up to 9682004056 Last checkpoint at 9682002296 This shows… of SHOW ENGINE INNODB STATUS: Database pages … realize that a single modified page…chunks of dirty pages get flushed) has… with those values and your write…
Post: MySQL 4 to MySQL 5 Upgrade performance regressions
June 6, 2007 By 8 Comments
…MySQL unable to keep up. Disks can do 80-150 single page fsyncs per second to get…SHOW PROCESSLIST” stuck in “end” stage or have “commit” queries in the processlist for multiple statement transactions. Looking at SHOW INNODB STATUS…
