… activities are overloading the system causing user experience to degrade. The first thing you need to know it is not MySQL problem… typically need to reduce concurrency to where it does not overload the system. Unless it is really time critical process I… heavily writing to database. Introduce Throttling Sometimes even single process overloads system too much in this case throttling by having relatively…
Comment: Which Linux distribution for a MySQL database server? A specific point of view.
March 15, 2012 By 37 Comments
… annoying for me part in Debian/Ubuntu is the /etc/mysql/debian-start and the ‘check_for_crashed_tables’ function (found in /usr/share/mysql/debian-start.inc.sh) which, among other things, does nasty… I/O overload for a long time. Another one is ridiculous 14 seconds to start in /etc/init.d/mysql. I regret…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
… unavailable plus in many cases you can use result overload to make MySQL to consume so much memory so it will swap…. General Overload As MySQL does not have much of resource utilization control you can simply run heavy queries to get MySQL Server barely… of the worse because they would both overload IO system and wipe off both MySQL and OS caches which can cause other…
Post: MySQL for Hosting Providers - how do they manage ?
November 28, 2008 By 15 Comments
… over a year ago about 10+ ways to crash or overload MySQL and since that people have come to me and suggested… ways to do the same. This is huge hole in MySQL design, thinking little about users isolations and resource quotas and…(1); SET @a13:=repeat(“a”,1000000); select sleep(1); … Causes MySQL to “leak” 1MB of memory per second with no apparent…
Post: How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
… responding very well but the server is abusing them and overloading them. And sometimes, of course, the CPUs and disks have… finish these, I’ll post them on Percona.TV, our MySQL video/screencast blog site. Another interesting topic is how to…. There are many things that can cause a stall in MySQL, and they usually begin microscopically and get worse over time…
Post: Logging MySQL queries from the client instead of the server
February 2, 2011 By 2 Comments
… single most valuable way to examine query execution on your MySQL server. Queries are logged with timing information, and in the… was forbidden by management, and when a server was so overloaded that nobody could get into it if they wanted to… mk-query-digest’s built-in ability to decode the MySQL wire protocol, it is certainly the easiest and best solution…
Post: Managing Slave Lag with MySQL Replication
October 12, 2007 By 11 Comments
…_BIN_LOG=0 before you run ALTER TABLE query. Replication Overload Many tutorials out where will give you impression problem with… slave. So watch your replication and see if it getting overloaded. Typically you will see it as increased lag spikes as… helpful to examine execution time of queries being replicated. Unfortunately MySQL Slow Query Log does not log replication queries. Though this…
Post: What do we optimize with mk-query-digest ?
December 15, 2009 By 2 Comments
… can see which are unrelated to query itself – general system overload, row level locks, table locks all could cause query response… it is often fine, assuming it is not causing system overload, interactive queries, which have real users waiting for them are…) – it is however perfectly possible to get bad performance with MySQL responsible for large portion of response time without any slow…
Post: Fighting MySQL Replication Lag
September 22, 2008 By 6 Comments
… already wrote about it. There are many aspects of managing mysql replication lag such as using proper hardware and configuring it… query design mistakes which result in low hanging fruit troubleshooting MySQL Replication Lag First fact you absolutely need to remember is… cases when you need this functionality. Finally you should not overload your replication – Quite typically I see replication lagging when batch…
Post: Database problems in MySQL/PHP Applications
August 11, 2006 By 12 Comments
… approach. The great things about objects is you can easily overload methods and get debugging and profiling tools, as well as… Store optimization, and I’m now on my own, offering MySQL and LAMP Consuilting Services. 2. Not using auto_increment functionality… by people with traditional database background. Things are different with MySQL. There are many successful applications, using tens of thousands of…
