…You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc/19018/stat 19018 (mysqld…to pretty IO bound load for me. But average is only average. It is a lot more interesting to look…does it cost to run a query. With Cloud Computing being hot a lot of Directors would like to…
Post: The two even more fundamental performance metrics
May 5, 2011 By 6 Comments
… also compute the average concurrency, throughput, response time, and utilization during the observation period: see the previous post for how to compute these… of response times. You can compute far more than just the averages we’ve seen how to compute up to this point. You… 50 microseconds, maybe a bit longer. This is common in MySQL servers I work with when they’re running a simple…
Post: Death match! EBS versus SSD price, performance, and QoS
February 21, 2011 By 54 Comments
… name, and the following statistics for reads: MB/s, average concurrency, and average response time in milliseconds. The same statistics are repeated… behind it, the device wouldn’t be 100% utilized until average read concurrency reached 6 and write concurrency reached 3. One… per month. I grabbed the counters from /proc/diskstats and computed I/O operations done so far on this array, at…
Post: MySQL 5.5.8 - in search of stability
January 3, 2011 By 11 Comments
… corresponds to changed pages in the buffer pool. You can compute this value as Log sequence number – Last checkpoint at from… most stable line I can get with MySQL 5.5.8. The 15-minute average result is 37235.06 NOTPM. This allows…_checkpoint=keep_average The 15-minute average result is 73529.73 NOTPM. The throughput is about 1.33x better than in “MySQL compatible…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… honest I do not really like averages Innodb provides as it is hard to get average for interval you want to have… id 1148250464, thread declared inside InnoDB 442 mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost… as well as computed averages. This is parameters which is great for graphing and monitoring. “16384 avg bytes/read” shows average size of…
Post: Computing 95 percentile in MySQL
November 28, 2008 By 5 Comments
… and similar values. The “average” is the evil of performance optimization and often as helpful as “average patient temperature in the hospital… table, so how to get the data if MySQL only provides you the avg: mysql> select count(*),avg(wtime) from performance_log… | 1.4469140766532 | +———-+—————–+ 1 row in set (2.08 sec) The average response time here is for example; the real data what…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
…-node communication One or more gearman queues are used to compute work. Computation is massively parallel. Shard-Query simply waits for all… centers. The response time should only be increased by the average latency, since work is done in parallel and there is… distribute work over any type of compute resource which speaks SQL, but right now only MySQL storage nodes are supported. Amdahl’s…
Post: Using LoadAvg for Performance Optimization
December 4, 2006 By 4 Comments
… average is is 3 numbers which correspond to “load average” calculated for one five and 15 minutes. It is computed as exponential moving average so most recent load have more weight in the value than old one. What does Load Average… if you run single batch job on the server with MySQL, Load Average is likely to be close to 1 even if…
Post: The four fundamental performance metrics
April 27, 2011 By 15 Comments
…aggregate metrics of activity on a system such as MySQL. In the best case, we want to know …period from 2a to 3c. It’s easy to compute this by just creating two counters and a last…s Law to derive these additional four long-term average metrics: Throughput: divide the number of queries in the…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 22 Comments
…by spreading the work over all available compute resources. In this test, Shard-Query averages a nearly 6x (max over 10x) …02 sec) Each year has tens of millions of flights: mysql> select count(*) from ontime_one.ontime_fact; +———–+ | count(*) | +———–+ | 135125787 | +———–+ …
