Emergency

Search Results for: ext3 read cache performance

table_cache negative scalability

Couple of months ago there was a post by FreshBooks on getting great performance improvements by lowering table_cache variable. So I decided to investigate what is really happening here. The “common sense” approach to tuning …


Innodb Performance Optimization Basics

Note: There is an updated post on this topic here. Interviewing people for our Job Openings I like to ask them a basic question – if you have a server with 16GB of RAM which …


ext4 vs xfs on SSD

As ext4 is a standard de facto filesystem for many modern Linux system, I am getting a lot of question if this is good for SSD, or something else (i.e. xfs) should be used. Traditionally …


Shard-Query EC2 images available

Infobright and InnoDB AMI images are now available There are now demonstration AMI images for Shard-Query. Each image comes pre-loaded with the data used in the previous Shard-Query blog post. The data in the each …


Attempting to Quantify Fragmentation Effects

We often hear from customers and MySQL experts that fragmentation causes problems such as wasting disk space, increasing backup times, and degrading performance. Typical remedies include periodic “optimize table” or dump and re-load (for example, …


Slow DROP TABLE

It is a known fact that ext3 is not the most efficient file system out there and for example file removals can be painfully slow and cause a lot of random I/O. However, as it …


MySQL File System Fragmentation Benchmarks

Few days ago I wrote about testing writing to many files and seeing how this affects sequential read performance. I was very interested to see how it shows itself with real tables so I’ve got …