May 24, 2013

MySQL for Hosting Providers – how do they manage ?

Working with number of hosting providers I always wonder how do they manage to keep things up given MySQL gives you so little ways to really restrict how much resources single user can consume. I have written over a year ago about 10+ ways to crash or overload MySQL and since that people have come [...]

New SpecJAppServer results at MySQL and Sun.

As you likely have seen Sun has posted the new SpecJAppServer Results More information from Tom Daly can be found here These results are quite interesting for me as I worked on some of the previous SpecJAppServer Benchmarks several years ago while being employed by MySQL. These are great results, plus they can be relevant [...]

How quickly you should expect to see bugs fixed

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 pool this bug makes database [...]

MySQL and Sun – Oportunity for smaller companies ?

Reading Martens interview we see the quite: “As soon as the deal closed we immediately secured a big deal with a major European national police agency,” said Mickos, now SVP database products at Sun. “Key to them choosing MySQL was that we are now part of a much larger public corporation. The deal wouldn’t have [...]

10+ Ways to Crash or Overload MySQL

People are sometimes contacting me and asking about bugs like this which provide a trivial way to crash MySQL to the user with basic privileges and asking me what to do. My answer to them is – there is nothing new to it and they just sit should back and relax Really – there are [...]

Heikki Tuuri answers to Innodb questions, Part II

I now got answers to the second portions of the questions you asked Heikki. If you have not seen the first part it can be found here. Same as during last time I will provide my comments for some of the answers under PZ and will use HT for original Heikkis answer. Q26: You also [...]

Innodb Recovery – Is large buffer pool always better ?

How does Buffer Pool size affects Innodb Performance ? I always expected the effect to be positive, Innodb with large buffer pool to performing better. Including Recovery of course. I even blogged about it. It turns out it is not always the case. Last week I was called to help with Innodb crash recovery on [...]

Mail clients and Databases

I get a lot of mail and I prefer to store it for long time if not forever. With modern hard disk sizes it should not be problem at all, but because of how mailing programs are written it causes a lot of problems. I’ve tried a lot of programs – Kmail, Evolution, Thunderbird on [...]

Are PHP persistent connections evil ?

As you probably know PHP “mysql” extension supported persistent connections but they were disabled in new “mysqli” extension, which is probably one of the reasons some people delay migration to this extension. The reason behind using persistent connections is of course reducing number of connects which are rather expensive, even though they are much faster [...]

Small things are better

Yesterday I had fun time repairing 1.5Tb ext3 partition, containing many millions of files. Of course it should have never happened – this was decent PowerEdge 2850 box with RAID volume, ECC memory and reliable CentOS 4.4 distribution but still it did. We had “journal failed” message in kernel log and filesystem needed to be [...]