by Vadim Tkachenko | Mar 2, 2009 | Hardware and Storage
We finally managed to get Intel X25-E SSD drive into our lab. I attached it to our Dell PowerEdge R900. The story making it running is worth separate mentioning – along with Intel X25-E I got HighPoint 2300 controller and CentOS 5.2 just could not start with two...
by Vadim Tkachenko | Feb 11, 2009 | Percona Software
One of InnoDB’s features is that memory allocated for internal tables definitions is not limited and may grow indefinitely. You may not notice it if you have an usual application with say 100-1000 tables. But for hosting providers and for user oriented...
by Vadim Tkachenko | Feb 2, 2009 | Percona Software
The problem with broken group commit was discusses many times, bug report was reported 3.5Â years ago and still not fixed in MySQLÂ 5.0/5.1 (and most likely will not be in MySQLÂ 5.1). Although the rough truth is this bug is very hard (if possible) to fix properly. In...
by Baron Schwartz | Jan 28, 2009 | Insight for DBAs
Are you running MySQL on Debian or Ubuntu with InnoDB? You might want to disable /etc/mysql/debian-start. When you run /etc/init.d/mysql start it runs this script, which runs mysqlcheck, which can destroy performance. It can happen on a server with MyISAM tables, if...
by Vadim Tkachenko | Jan 18, 2009 | Benchmarks, Percona Software
Recently I wrote about InnoDB scalability on 24-core box, and we made research of scalability problems in sysbench write workload (benchmark emulates intensive insert/delete queries). By our results the problem is in concurrency on rollback segment, which by default...
by Peter Zaitsev | Jan 13, 2009 | Insight for DBAs
Despite being standard Innodb feature forever Insert Buffers remains some kind of mysterious thing for a lot of people, so let me try to explain thing a little bit. Innodb uses insert buffer to “cheat” and not to update index leaf pages when at once but...
by Peter Zaitsev | Jan 12, 2009 | Insight for DBAs
There is significant portion of customers which are still using MyISAM when they come to us, so one of the big questions is when it is feasible to move to Innodb and when staying on MyISAM is preferred ? I generally prefer to see Innodb as the main storage engine...
by Vadim Tkachenko | Dec 29, 2008 | Benchmarks
One of our customers gave me a chance to run some benchmarks on 24-core (intel cpu based) server, and I could not miss it and ran few CPU-bound tasks there. The goal of benchmarks was investigation of InnoDB-plugin and XtraDB scalability in CPU-bound load. CPU...
by Peter Zaitsev | Dec 17, 2008 | Insight for DBAs
So lets say you have .frm file for the table and you need to recover CREATE TABLE statement for this table. In particular when we do Innodb Recovery we often get .frm files and some mess in the Innodb tablespace from which we have to get data from. Of course we could...
by Peter Zaitsev | Dec 16, 2008 | Insight for DBAs
How much space would empty MyISAM table take ? Probably 8K for .frm file, 1KB for .MYI file and 0 for MYD file. .MYI file can be larger if you have many indexes. How much space will Innodb take: mysql> create table test_innodb(a int, b int) engine=innodb; Query OK,...
by Peter Zaitsev | Dec 3, 2008 | Benchmarks
We’ve recently done benchmarks comparing different MySQL versions in terms of their CPU efficiently in TPC-C like Workload. We did it couple of weeks ago so MySQL 5.0.67, MySQL 5.1.29 and Innodb Plugin 1.0.1 were used which are not very recent, though we do not...
by Baron Schwartz | Nov 21, 2008 | Insight for DBAs
Peter wrote a post a while ago about choosing 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 size! So I thought I’d clarify it a little....
by Yasufumi Kinoshita | Nov 13, 2008 | Benchmarks, Percona Software
Do you know that there are two limits about dirty (modified but not flushed to disk) blocks of InnoDB buffer pool? One is the limit of “amount”. The other is the limit of “age”. — limit of “amount” — As you know, buffer...
by Vadim Tkachenko | Nov 1, 2008 | Percona Events
This is a fantastic addition to the Percona team. Congratulations.
by Maciej Dobrzanski | Oct 31, 2008 | Insight for DBAs
When running InnoDB you are able to dig into the engine internals, look at various gauges and counters, see past deadlocks and the list of all open transactions. This is in your reach with one simple command — SHOW ENGINE InnoDB STATUS 1 SHOW ENGINE InnoDB...
by Vadim Tkachenko | Oct 20, 2008 | Percona Software
There is patch from Google to improve SMP performance , but for some workloads it showed for us reverse scalability. E.g. update_key benchmark from sysbench. There are also results with Yasufumi’s rw_locks (http://bugs.mysql.com/bug.php?id=26442) ThreadsStandard...
by Vadim Tkachenko | Sep 28, 2008 | Insight for DBAs
Ever wonder what is stored in InnoDB buffer pool at the moment ? It is not so hard actually – we made a short patch for MySQL 5.0 which show innodb buffer pool content mysql> select * from information_schema.INNODB_BUFFER_POOL_CONTENT;...
by Vadim Tkachenko | Sep 9, 2008 | Benchmarks, Percona Software
We are going to show the effects of the new patches applied to Percona HighPerf release. As you see from the following graphs, there is significant difference to normal version when the data bigger than buffer pool (right graph shows CPU usage) The workload emulates...
by Vadim Tkachenko | Sep 8, 2008 | Percona Software
We gathered together our ideas of MySQL improvements on this page https://www.percona.com/percona-lab/dev-plan.html and we are going to implement some of them. My favorite one is – make InnoDB files .ibd (one created with –innodb-file-per-table=1) movable...
by Peter Zaitsev | Sep 4, 2008 | Percona Events
Over a year ago I wrote about pretty nasty Innodb Recovery Bug. I ran in the same situation again (different system, different customer) and went to see the status of the bug… and it is still open. You may thing it is minor issue but in fact with large buffer...
