…of concept, I’ll built 2 m1.small instances, fell free to use other types. At the time I wrote this, the…. The first thing to is to set up the hostname on both host. Heartbeat identifies the…the configuration file per say. On both host, the chosen key in the authkeys file must be identical and good…
Post: High availability for MySQL on Amazon EC2 – Part 2 - Setting up the initial instances
June 29, 2010 By 9 Comments
Post: On Good Instrumentation
May 31, 2010 By 1 Comment
… how much more efficient things could be going if only there would be a good instrumentation available. Most of applications out there have… the small sample of requests, though it needs to be detailed. Typically you would include the calls to the lower level services together with timestamp, the…
Post: The MySQL optimizer, the OS cache, and sequential versus random I/O
April 28, 2008 By 17 Comments
…. The unit of cost for the MySQL query optimizer is a single random 4k data page read. In general, it’s a pretty good… joining to the dimension tables doesn’t slow the query perceptibly, because these tables are small and they stay in memory, in the OS… of these had to go to disk, our STRAIGHT_JOIN plan would take more than a month to complete! Good thing we know the…
Post: Just do the math!
July 6, 2009 By 4 Comments
… small and young and with 10000 page views a day you few days of history the queries… reporting for up to the whole year worth of data you find things not working any more…good benchmarks are important to get exact numbers for the application and see if they match your model predictions. As result of…
Post: How to calculate a good InnoDB log file size
November 21, 2008 By 38 Comments
… a good InnoDB log file size. Not to pick on Peter, but the post actually kind of talks about a lot of things and then doesn’t tell you how to choose a good log file… look surprisingly small? It might. I commonly see log file sizes in the gigabyte ranges. But that’s generally a mistake. The server…
Post: Setting up XFS on Hardware RAID -- the simple edition
December 16, 2011 By 9 Comments
…aligned with the RAID stripes? It takes a small amount of math: …the start sector of the partition by the sectors per stripe: 27344896 / 128 = 213632. This is a whole number, so we are good…things: RAID stripe size Number of unique, utilized disks in the RAID. This turns out to be the same as the…
Post: Getting use of Slave in MySQL Replication
February 14, 2007 By 15 Comments
…the slave replication lag can be significant. Also even very small lag can cause the problems – for example you’ve posted comment on the…the dedicated slave for the duration of session which is both good from performance standpoint as he is likely to touch the…
Post: The case for getting rid of duplicate “sets”
May 17, 2011 By 2 Comments
…too small for you to notice an effective change. Lets say I have a table of…the data is stored inside of a histogram in the set. The cardinality and the distribution is always known. Second, computation on the… 4 rows in set (0.00 sec) Great, things are looking good. What if we were to …
Post: Effect of adaptive_flushing
December 4, 2009 By 5 Comments
… one troubling thing: ~2GB of uncheckpointed data….good for performance because InnodB does not need to consider as many old versions of rows. Here we can see the…the checkpoint age was comparable to the log file size, however the behavior with flushing enabled (keeping the checkpoint age very small…
Post: Finding your MySQL High-Availability solution - The definitions
October 9, 2009 By 10 Comments
…of the time, the samples are small and all the conditions of the deployments are not easily controlled. See the level of availability as the availability you, as the operator of the…the importance of the application. Single point of failure (SPOF) Single points of failure are the things…
