…, not just for new connections as in MySQL. This is very helpful for measurement as otherwise we might not catch some long… the statistics available after the query is actually executed, while no such statistics are available for queries that are logged using the general query log…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… published for example is good for measuring scalability of the system as concurrency …query ? You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql…queries running will give average CPU usage per query. If you’re running Percona Server you can get the value from User Statistics…
Post: How to Identify Bad Queries in MySQL
January 10, 2011 By 16 Comments
… the timestamp when the query executed, not merely the duration the query executed for, which has been available in MySQL for years. This is necessary for determining whether a group of queries completed… mk-query-digest do to this missing analytical step. I have done it many times with simple awk scripts and various statistical measures…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
… production servers, with powerful hardware and heavy query workloads. Both have a key_buffer_size … interval I used to measure the statistics on those two servers. Maybe I measured the first server … results to your IO system’s capabilities. MySQL doesn’t have good instrumentation for scientifically …
Comment: The four fundamental performance metrics
April 27, 2011 By 15 Comments
… know the official terminology for mysql). Let’s take query throughput (X) as a concrete example. Each query event is accumulated in the… oft-used “performance statistics” to remind myself that we first must have reliable and meaningful base metrics or measurements before we can…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
…-slave-statements. THE DETAILED INFORMATION ABOUT QUERY EXECUTION Each query can be executed in various ways…. the InnoDB usage statistics. MySQL currently allows you to see many per-session statistics for operations with…, unfortunatelly there is no good way to measure that. InnoDB_IO_r_bytes is the…
Post: Introducing tcprstat, a TCP response time tool
August 31, 2010 By 12 Comments
… for? In a nutshell, it is a lightweight way to measure response times on a server such as a database, memcached…. The tcprstat tool itself is a means of gathering raw statistics, which are suitable for storing and manipulating with other programs… protocols such as HTTP and MySQL, this is the moral equivalent of a query‘s response time. The statistics we chose to output…
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
…MySQL Server. set userstat_running=1 and run following query: mysql> select * from information_schema.user_statistics where user=”#mysql_system#” \G *************************** 1. row *************************** USER: #mysql… it too). First I would measure replication capacity on 5 minute intervals …
Post: Intro to OLAP
July 12, 2010 By 9 Comments
…OLAP (or online analytical processing) tools using MySQL and other free open source software….tool must generate to answer those queries. Performance challenges with larger databases, and… form of statistical analysis. In multidimensional analysis samples representing a particular measure are compared…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… counters, statistics, information about transaction processing and all kinds of other things. In MySQL 5 number… InnoDB 442 mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost… can see buffer pool hit ratio which measures buffer pool efficiency. 1000/1000 corresponds to …
