… to second. I draw boxplots, which show 25-50-75 percentiles. So there is no grow in throughput after 2 threads… good question how does it affect MySQL performance, and I am going to run some MySQL workloads on these cards to understand… you are interested more in SSD and MySQL questions – I will be giving a webinary “MySQL and SSD” on May-9. It…
Comment: Introducing new type of benchmark
February 26, 2012 By 16 Comments
… a bit smoke and mirrors. You dont know your 9x percentile response time performance until you use it against your work… have a sharded datastore. A possible solution is to use mysql proxy and an alterate server with a snapshotted dataset and…
Post: Computing 95 percentile in MySQL
November 28, 2008 By 5 Comments
… doing performance analyzes you often would want to see 95 percentile, 99 percentile and similar values. The “average” is the evil of… response time goal in 95 or 99 percentile is much better. Say you say 99 percentile response time should be one second…/99 percentile and get your logs in the table, so how to get the data if MySQL only provides you the avg: mysql…
Post: Evaluating IO subsystem performance for MySQL Needs
March 5, 2008 By 23 Comments
… should expect from the system. What I usually look for MySQL is performance in random reads and random writes. Sequential reads…: 0.0001s avg: 0.0001s max: 0.0086s approx. 95 percentile: 0.0001s Threads fairness: events (avg/stddev): 773835.0000/0….0027s max: 0.0112s approx. 95 percentile: 0.0030s So we get about 3ms 95 percentile request time – not bad – all request…
Post: mysql-proxy, urgh performance and scalability ?
June 9, 2009 By 27 Comments
… thread). MySQL per-request statistics: min: 1.31ms avg: 1.51ms max: 5.30ms approx. 95 percentile: 1.56ms Proxy+MySQL per-request statistics: min: 2.04ms avg: 2.86ms max: 6.44ms approx. 95 percentile: 4… consider if you want to run Query Analyzer with MySQL-proxy on your MySQL Enterprise setup. There is alternative – Dormando-proxy, which…
Post: Virtualization and IO Modes = Extra Complexity
March 21, 2011 By 12 Comments
…: 0.04ms avg: 0.06ms max: 0.34ms approx. 95 percentile: 0.06ms Threads fairness: events (avg/stddev): 1343.0000/0…: 0.10ms avg: 1.11ms max: 259.69ms approx. 95 percentile: 5.31ms Threads fairness: events (avg/stddev): 33900.0000/0…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… enable logging atomically, not just for new connections as in MySQL. This is very helpful for measurement as otherwise we might… importance to the times/values reported in the 95% (95th percentile) column as that gives us more accurate understanding. Now, for… underlying tables involved and the query execution plan used by MySQL. The end result might be that you end up limiting…
Post: What do we optimize with mk-query-digest ?
December 15, 2009 By 2 Comments
… for interactive queries. It is best to look at 95 percentile “time” rather than slowest time for the queries as there… to be optimized. It helps if batch jobs use different MySQL user compared to the web site itself as it makes…) – it is however perfectly possible to get bad performance with MySQL responsible for large portion of response time without any slow…
Post: The two even more fundamental performance metrics
May 5, 2011 By 6 Comments
…. You can calculate the standard deviation, the median, any desired percentile (depending on how large your sample is), the variance, the… 50 microseconds, maybe a bit longer. This is common in MySQL servers I work with when they’re running a simple…
Post: Introducing tcprstat, a TCP response time tool
August 31, 2010 By 12 Comments
… outbound packet. For many simple protocols such as HTTP and MySQL, this is the moral equivalent of a query’s response…, in microseconds. These are repeated for the 95th and 99th percentiles as well. Other metrics are also available. Here’s a…
