…we’ve chosen the statistics carefully so you can compute meaningful things about your TCP traffic. What is…. For many simple protocols such as HTTP and MySQL, this is the moral equivalent of a query… to output by default are the count, median, average, min, max, and standard deviation of the response …
Post: Color code your performance numbers
June 2, 2010 By 4 Comments
… not handy to look at the averages, min or max times – something what is easily computed using built in aggregate functions. We… 3 seconds and anything over that will be considered unacceptable: mysql> select sum(wtime=1.0 and wtime=3.)/count(*)*100… Six Sigma practices. However given variance is the same better average response time for good requests helps us to track performance…
Comment: MySQL File System Fragmentation Benchmarks
July 9, 2008 By 28 Comments
…. Could you post the my.cnf file used and the computer hardware specs that produced this benchmark. I am interested in… tests: computer 1: My.ini [client] port=3306 [mysql] default-character-set=latin1 [mysqld] port=3306 basedir=”C:/Program Files/MySQL/MySQL Server 5… 1186 and 1177 inserts per second into the table the average data length was 231B. It seemed the writing of the…
Post: Using flow control functions for performance monitoring queries
May 24, 2008 By 12 Comments
… hardly be optimized well by MySQL Optimizer. One way I find IF statement very useful is computing multiple aggregates over different set… generation log for some site and reports number of requests, average request time as well as classifies requests to multiple classes…. On the side note I should say the average time is least usable because average does not tell you a lot. It…
Comment: The four fundamental performance metrics
April 27, 2011 By 15 Comments
…I believe Baron is trying to construct something out mysql performance counters because not much is already available … much later on, although not always (cf. load average == EMA http://www.perfdynamics.com/papers.html#tth_sEc23… we can do anything with them, such as compute other derived metrics or …
Post: How much space does empty Innodb table take ?
December 16, 2008 By 7 Comments
… another field which may need an explanation. This value is computed by dividing Data_Length (exact number) by number of rows…. For example it will show 16K as average row size for table with one row: mysql> show table status like “test_innodb… 9MB): -rw-rw—- 1 mysql mysql 8578 Dec 16 20:58 test_innodb.frm -rw-rw—- 1 mysql mysql 9437184 Dec 16 21:06…
Post: Using MyISAM in production
June 17, 2006 By 36 Comments
…. For example running full table scan query to compute some stats is often impossible in production as… Just one is enough. Lock priorities. By default MySQL treats updates as higher priority operations. You can…extreme cases I’ve seen over 10 pieces in average per row – this is when rows contain some…
Post: How To Test Your Upgrades - pt-upgrade
December 29, 2011 By 7 Comments
…skips the overhead pt-query-digest had to compute # values for reports pt-query-digest –print –no… if you are upgrading your hardware alongside your MySQL version, you should also consider running these …the query times. The most important is the average (avg) which tells in general how each …
Post: Predicting Performance improvements from memory increase
August 7, 2008 By 6 Comments
…much IO bound anyway. Interesting enough because of MySQL scaling issues it is also possible to …same and the goal may not be optimizing average performance. It may be heavy data processing … so account for that. Besides pure CPU based computation you should account for locking. Consider for example…
Comment: Managing Slave Lag with MySQL Replication
October 12, 2007 By 15 Comments
…_STATISTICS’ functionality from the Google patch into MySQL, then you can compute replication load average using the Busy_time output for the system…
