Last week wasn’t so active in terms of new development, because many of us were at the MySQL conference, of course. However, we did push out the XtraBackup 1.6 release, and began work on backporting some features from MySQL 5.6 to 5.1 for a certain large customer. Several of the features we’ve added in 5.0 [...]
How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
Among the many things that can cause a “server stall” is a long-running transaction. If a transaction remains open for a very long time without committing, and has modified data, then other transactions could block and fail with a lock wait timeout. The problem is, it can be very difficult to find the offending code [...]
Innodb undo segment size and transaction isolation
January 12, 2011 By 3 Comments
You might know if you have long running transactions you’re risking having a lot of “garbage” accumulated in undo segment size which can cause performance degradation as well as increased disk space usage. Long transactions can also be bad for other reasons such as taking row level locks which will prevent other transactions for execution, [...]
When does Innodb Start Transaction ?
January 11, 2011 By 9 Comments
When does Innodb Start Transaction ? The answer looks obvious – when you issue “BEGIN” command. This is however wrong answer from engine point of you. Run “SHOW INNODB STATUS” and you will see “not started” status in transaction list. It is only when you read (or write) to INNODB table you can see transaction [...]
Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and [...]
MySQL 5.5.8 – in search of stability
January 3, 2011 By 11 Comments
A couple of days ago, Dimitri published a blog post, Analyzing Percona’s TPCC-like Workload on MySQL 5.5, which was a response to my post, MySQL 5.5.8 and Percona Server: being adaptive. I will refer to Dimitri’s article as article [1]. As always, Dimitri has provided a very detailed and thoughtful article, and I strongly recommend reading if [...]
Percona Server 5.1.49-rel12.0
September 15, 2010 By 6 Comments
Dear Community, Starting with this release, we introduce a new release model for Percona Server. From now on, we will have both Stable and Release Candidate releases. Release Candidates will introduce new features not yet available in Stable releases. Along with new features, our new 5.1.49-12.0 RC contains a couple of patches from the Facebook-MySQL [...]
Purge Thread Spiral of Death
June 10, 2010 By 5 Comments
I just wrote a large post on reasons for innodb main tablespace excessive growth and I thought it would make sense to explain briefly of why it is so frequently you have purge not being the problem at all and when out of no where you can see purge thread being unable to keep up [...]
Reasons for run-away main Innodb Tablespace
June 10, 2010 By 2 Comments
So you’re running MySQL With innodb_file_per_table option but your ibdata1 file which holds main (or system) tablespace have grown dramatically from its starting 10MB size. What could be the reason of this growth and what you can do about it ? There are few things which are always stored in main tablespace – these are [...]
Percona-XtraDB-9.1: released and new coming features
March 17, 2010 By 14 Comments
Recently Alexandr announced new Percona-XtraDB-9.1 release, and now it is good time to summarize features we have and what is expected soon. This release contains long waited features from 5.0: extended slow.log USER/TABLE/INDEX/CLIENT_STATISTICS + THREAD_STATISTICS ( coming in release-10) Extended slow.log is now even more extended, there is additional information for each query:
1 | # Bytes_sent: 4973 Tmp_tables: 1 Tmp_disk_tables: 1 Tmp_table_sizes: 7808 |
That [...]
