by Ewen Fortune | Sep 29, 2008 | Insight for DBAs
Recently I was tasked with investigating slippage between master and slave in a standard replication setup. The client was using Maatkit’s mk-table-checksum to check his slave data was indeed a fair copy of that of the master. mk-table-checksum...
by Peter Zaitsev | Sep 22, 2008 | Insight for DBAs
The problem of MySQL Replication unable to catch up is quite common in MySQL world and in fact I already wrote about it. There are many aspects of managing mysql replication lag such as using proper hardware and configuring it properly. In this post I will just look...
by Ewen Fortune | Sep 22, 2008 | Percona Software
Whilst working with a client recently I noticed a large number of temporary tables being created on disk. show global status like 'Created_tmp%' | Created_tmp_disk_tables | 91970 | | Created_tmp_files | 19624 | | Created_tmp_tables | 1617031 | 12345 show global status...
by Peter Zaitsev | Sep 16, 2008 | Insight for DBAs
Quite commonly I get a question similar to this – “My Innodb Buffer Pool is already 90% full, should I be thinking about upgrading memory already?” This is a wrong way to put the question. Unless you have very small database (read as database which...
by Vadim Tkachenko | Sep 12, 2008 | Percona Software
Usually unused indexes are devil, they waste diskspace, cache, they make INSERT / DELETE / UPDATE operations slower and what makes them worse – it is hard to find them. But now ( with userstatsV2.patch) you can find all unused indexes (since last restart of...
by Peter Zaitsev | Sep 12, 2008 | Insight for DBAs
What bug makes you to recommend upgrading most frequently ? For me it is this bug which makes it quite painful to automate various replication tasks. It is not the most critical bug by far but this makes it worse – critical bugs would usually cause upgrades...
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...
by Peter Zaitsev | Sep 1, 2008 | Insight for DBAs
This week I’ve worked with the customer doing certain work during maintenance window which involved a lot of data copying around between MySQL boxes. We had prepared well and had measured how fast we could copy the data between servers of these kind connected to...
by Peter Zaitsev | Aug 22, 2008 | Percona Events
We’ve discussed today how we should implement MySQL Version advisory in mk-audit tool. One obvious questions was to look at the end of life – it is often bad idea to run MySQL versions past end of life as even security bugs may not be fixed in these...
by Peter Zaitsev | Aug 21, 2008 | Insight for DBAs
Quite common beginners mistake is not to understand how indexing works and so index all columns used in the queries…. separately. So you end up with table which has say 20 indexes but all single column ones. This can be spotted with a glance view. If you have...
by Peter Zaitsev | Aug 21, 2008 | Hardware and Storage
So you need to design highly available MySQL powered system… how do you approach that ? Too often I see the question is approached by focusing on expensive hardware which in theory should be reliable. And this really can work quite well for small systems. It is...
by Peter Zaitsev | Aug 18, 2008 | Insight for Developers
Today I worked on rather interesting customer problem. Site was subject what was considered DDOS and solution was implemented to protect from it. However in addition to banning the intruders IPs it banned IPs of web services which were very actively used by the...
by Peter Zaitsev | Aug 12, 2008 | Insight for DBAs
Today I was working with the client loading data to MyISAM tables at very high rate. Hundreds of millions rows are loaded daily into single MySQL instance with bursts up to 100K of records/sec which need to be inserted (in the table with few indexes). It was good not...
by Peter Zaitsev | Aug 9, 2008 | Insight for Developers
Quite commonly in applications, you would need to use some kind of “status” field – the status of an order – “new”, “confirmed”, “in production”, “shipped” status of a job, message, etc. People...
by Peter Zaitsev | Aug 7, 2008 | Insight for DBAs
One common question I guess is how much should I see performance improved in case I increase memory say from 16GB to 32GB. The benefit indeed can be very application dependent – if you have working set of say 30GB with uniform data access raising memory from...
by Evgeniy Firsov | Aug 4, 2008 | Percona Software
Recently, we added information schema support to Google’s userstats patch. There are three information schema tables added: user_statistics, table_statistics, index_statistics. One can now use select * from information_schema.user_statistics along with show...
by Peter Zaitsev | Aug 2, 2008 | Insight for DBAs
Quite frequently I see customers looking at MySQL recovery as on ability to restore data from backup which can be far from being enough to restore the whole system to operating state, especially for complex systems. Instead of looking just at data restore process you...
by Vadim Tkachenko | Jul 31, 2008 | Percona Software
We prepared RPMs of our release for RedHat 5 / CentOS 5 x86_64 platform. https://www.percona.com/blog/mysql/RPM/RHEL5/5.0.62/ There was question what patcheset includes and if there is manuals. We have: microsecond resolution in slow-log extended query plan in...
by Vadim Tkachenko | Jul 24, 2008 | Percona Software
As there were many requests for Debian binary packages in our announcement of Percona builds with custom patchsets, we decided to play with it and built .deb, which you can find there: Debian You can also add the following repositories into your sources.list: deb...
by Vadim Tkachenko | Jul 16, 2008 | Percona Software
Percona has a strong team of MySQL developers and consultants on board, so we decided to prepare builds with our patches and third-party patches which we think are very useful. We actually use these internally and for our customers. Current releases include: microslow...
