April 21, 2014

RAID throughput on FusionIO

Along with maximal possible fsync/sec it is interesting how different software RAID modes affects throughput on FusionIO cards. In short conclusion, RAID10 modes really disappoint me, the detailed numbers to follow. To get numbers I run

test with 16KB page size, random read and writes, 1 and 16 threads, O_DIRECT mode. FusionIO cards are […]

FusionIO – time for benchmarks

I posted about FusionIO couple times RAID vs SSD vs FusionIO and Testing FusionIO: strict_sync is too strict…. The problem was that FusionIO did not provide durability or results were too bad in strict mode, so I lost interest FusionIO for couple month. But I should express respect to FusionIO team, they did not ignore […]

Air traffic queries in InfiniDB: early alpha

As Calpont announced availability of InfiniDB I surely couldn’t miss a chance to compare it with previously tested databases in the same environment. See my previous posts on this topic: Analyzing air traffic performance with InfoBright and MonetDB Air traffic queries in LucidDB I could not run all queries against InfiniDB and I met some […]

7 Reasons why MySQL Quality will never be the same

I had a call with Monty the other day and I told him why I think MySQL Server Quality will never be the same again. I’ve been thinking a bit more about it and here is the extended list. In particular I think MySQL Server will never be able to reach its original quality guidelines […]

Recovering Innodb table Corruption

Assume you’re running MySQL with Innodb tables and you’ve got crappy hardware, driver bug, kernel bug, unlucky power failure or some rare MySQL bug and some pages in Innodb tablespace got corrupted. In such cases Innodb will typically print something like this: InnoDB: Database page corruption on disk or a failed InnoDB: file read of […]

No more MySQL Crash Safe Replication in 5.0 ?

As you might know even if you’re only using Innodb tables your replication is not completely crash safe – if Slave MySQL Server crashes/power goes down it is likely for relay logs to run out of sync (they are not synced to the disk) plus position on the master which slave remembers becomes stale. During […]

MySQL 4 to MySQL 5 Upgrade performance regressions

This week I already had two serious performance regression cases when upgrading from MySQL 4.0 and 4.1 to MySQL 5.0. By serious I mean several times performance difference not just 5-10% you often see for simple queries due to generally fatter code. The problem in both cases was MySQL 5.0 broken group commit bug. First […]

MySQL Installation and upgrade scripts.

I generally find MySQL Sever sufficiently tested, meaning at least minor version upgrades rarely cause the problems. Of course it is not perfect and I remember number of big issues when some releases could not be used due to behavior changes in them and when something had to be rolled back in the next release. […]

MyISAM mmap feature (5.1)

As you know MyISAM does not cache data, only indexes. MyISAM assumes OS cache is good enough and uses pread/pwrite system calls for reading/writing datafiles. However OS is not always good in this task, my benchmarks show Linux/Solaris aren’t scalable on intensive pread calls (I believe the same for Windows, but I did not test […]

Presentations

This page is not updated anymore. For new presentations, please check the presentations page on our company website. We love speaking at conferences and other events. Please contact us if you’d like us to present at yours! We can also give internal presentations for your company or group. Sphinx search engine for RDBMS Egypt, December […]