…. 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 13 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…
Post: Performance Optimization and Six Sigma
June 7, 2010 By 6 Comments
… and not acceptable. So how are doing with this in MySQL (and general Web performance management) ? Not So good. In most… my talks about performance measurements I suggested to measure 95 percentile over short period of times for example every minute, which… believe meeting 95 percentile response time every minute of the day is a lot harder than getting 99 percentile over 24 hours…
Post: Color code your performance numbers
June 2, 2010 By 4 Comments
…. We most likely would like to see some percentile numbers – 95 percentile or 99 percentile. The problem is computing these in SQL is… 3 seconds and anything over that will be considered unacceptable: mysql> select sum(wtime=1.0 and wtime=3.)/count(*)*100… before we get large number of yellow or red requests: mysql> select avg(if(wtime
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 5 Comments
… affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> SELECT COUNT(*) FROM test_table; — 3 Tickets Used +———-+ | COUNT(*) | +———-+ | 3… scenario, you will tune innodb_concurrency_tickets to the 99th percentile of small PK lookups. If you’re optimizing for response… –oltp-dist-type=uniform –max-time=300 –mysql-user=root –mysql-socket=/var/lib/mysql/mysql.sock run Applicable my.cnf settings: innodb_buffer…
Post: Goal driven performance optimization
December 22, 2008 By Leave a Comment
… other interactions for many applications, and also we speak about percentile response time rather than “all queries”. It is surely good… of the problematic pages: mysql> select count(*),avg(wtime),avg(utime/wtime) cpu_ratio, avg(mysql_time/wtime) mysql_ratio ,avg(sphinx_time… for complex applications using mutliple components (like sphinx and MySQL) or multiple MySQL Servers because in these cases you often can’t…
Post: Testing Intel SSD 520
May 1, 2012 By 8 Comments
… 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: MySQL Performance on Memory Appliance
February 11, 2009 By 23 Comments
… sysbench –test=oltp –mysql-table-engine=innodb –oltp-table-size=1000000 –mysql-socket=/tmp/mysql.sock –mysql-db=test –mysql-user=root –mysql-password= prepare sysbench…: 0.0035s avg: 0.0481s max: 1.0817s approx. 95 percentile: 0.1054s Threads fairness: events (avg/stddev): 6250.0625/90…
Comment: MySQL Performance on Memory Appliance
February 11, 2009 By 23 Comments
… –oltp-table-size=1000000 –db-driver=mysql –mysql-table-engine=innodb –mysql-socket=/var/lib/mysql/mysql.sock –mysql-user=root prepare sysbench –num-threads=16 –max-requests=100000 –test=oltp –mysql-table-engine=innodb –db-driver=mysql –mysql-socket=/var/lib/mysql/mysql.sock –mysql-user=root run Doing OLTP test…: 0.0027s avg: 0.0115s max: 0.0979s approx. 95 percentile: 0.0313s Threads fairness: events (avg/stddev): 6250.1250/66…
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…
