RE: SHOW INNODB STATUS - FILE I/O - OS reads/writes/syncs?
SHOW GLOBAL STATUS LIKE 'Innodb%'; Then do some math -- usually dividing by Uptime. That will give you some insight in how hard the I/O is working, and how full the buffer_pool is. -Original Message- From: Rafał Radecki [mailto:radecki.ra...@gmail.com] Sent: Friday, June 21, 2013 4:59 AM To: mysql@lists.mysql.com Subject: SHOW INNODB STATUS - FILE I/O - OS reads/writes/syncs? Hi All. I've searched but with no luck... what do exactly these variables mean: 1343928 OS file reads, 1085452262 OS file writes, 19976022 OS fsyncs ? I am wondering if my innodb_buffer_pool setting is not to low. Does 'file reads' show number of times innodb files have been read into memory from server's start? What about file writes/fsyncs? Best regards, Rafal Radecki. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: SHOW INNODB STATUS - FILE I/O - OS reads/writes/syncs?
As I can see the changes in these values are use by percona cacti monitoring templates to graph InnoDB I/O. Can anyone answer the question finally? ;) 2013/6/21 Hartmut Holzgraefe hart...@skysql.com On 21.06.2013 13:59, Rafał Radecki wrote: Hi All. I've searched but with no luck... what do exactly these variables mean: 1343928 OS file reads, 1085452262 OS file writes, 19976022 OS fsyncs ? these are the total number of reads/writes/fsyncs (number of system calls actually?) since the server started (or maybe last FLUSH call?) and not very meaningful by themselves without knowing the time span it took to come up to those counter values. The per second values on the following line are much more interesting. http://www.mysqlperformanceblog.com/2006/07/17/show-innodb-status-walk-through/ has a pretty good description of the SHOW ENGINE INNODB STATUS output, even though it is not too detailed in this specific section. -- Hartmut Holzgraefe hart...@skysql.com Principal Support Engineer (EMEA) SkySQL AB - http://www.skysql.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: SHOW INNODB STATUS - FILE I/O - OS reads/writes/syncs?
Hello Rafał, On 6/24/2013 4:26 AM, Rafał Radecki wrote: As I can see the changes in these values are use by percona cacti monitoring templates to graph InnoDB I/O. Can anyone answer the question finally? ;) 2013/6/21 Hartmut Holzgraefe hart...@skysql.com On 21.06.2013 13:59, Rafał Radecki wrote: Hi All. I've searched but with no luck... what do exactly these variables mean: 1343928 OS file reads, 1085452262 OS file writes, 19976022 OS fsyncs ? these are the total number of reads/writes/fsyncs (number of system calls actually?) since the server started (or maybe last FLUSH call?) and not very meaningful by themselves without knowing the time span it took to come up to those counter values. The per second values on the following line are much more interesting. I don't understand how Hartmut's answer was insufficient. The InnoDB engine must get data from the disk (reads), send data to the disk (writes), and occasionally tell the operating system that it must flush its buffers to disk to ensure durability (fsync). Why are you so interested in these numbers? -- Shawn Green MySQL Principal Technical Support Engineer Oracle USA, Inc. - Hardware and Software, Engineered to Work Together. Office: Blountville, TN -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: SHOW INNODB STATUS - FILE I/O - OS reads/writes/syncs?
On 21.06.2013 13:59, Rafał Radecki wrote: Hi All. I've searched but with no luck... what do exactly these variables mean: 1343928 OS file reads, 1085452262 OS file writes, 19976022 OS fsyncs ? these are the total number of reads/writes/fsyncs (number of system calls actually?) since the server started (or maybe last FLUSH call?) and not very meaningful by themselves without knowing the time span it took to come up to those counter values. The per second values on the following line are much more interesting. http://www.mysqlperformanceblog.com/2006/07/17/show-innodb-status-walk-through/ has a pretty good description of the SHOW ENGINE INNODB STATUS output, even though it is not too detailed in this specific section. -- Hartmut Holzgraefe hart...@skysql.com Principal Support Engineer (EMEA) SkySQL AB - http://www.skysql.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
