Category Archives: Oracle

Performance and scalability improvements in Mysql 5.5

Oracle’s Mysql Blog has a very good post that provides an overview of some of the improvements that you can expect in the upcoming Mysql 5.5 release.

This writeup focuses mainly on the changes as they relate to performance and scalability, however the author (Rob Young) expresses his plans to discuss other aspects as well, sometime in the near future.

Here are just a few of the topics covered by Rob:

  • Improved Default Thread Concurrency
  • Improved Recovery Performance
  • Multiple Buffer Pool Instances
  • Native Asynchronous I/O for Linux
  • Improved Metadata Locking Within Transactions
  • Better performance on Windows based installs

At some point I hope to continue my testing and benchmarking of several different versions of Mysql such as MariaDB, Percona and Mysql 5.5. However for production databases we will be sticking with the Mysql 5.1.x code branch for the foreseeable feature.

Btrfs: The Story So Far

Here is a link to a video presentation given by Josef Bacik, one of the 3 lead developers currently working on Btrfs.  This presentation was given at at LinuxCon Brazil 2010.  The video lasts about an hour and according to the description provides:

‘A look at the features that currently exist in Btrfs and what features are left to be done. We’ll look at stability and what things testers need to look out for. There will be plenty of benchmarks and use cases for the different features of Btrfs. We will also discuss what testing needs to be done, and how testers can help us developers.’

If you have some questions about the current state of Btrfs, current and future Btrfs development roadmap,  benchmarks, etc… you should take some time to watch this video.

Current state of “Btrfs” File System for Linux

Oracle has provided  a link to a webcast (registration required) on the state of Btrfs given,  by lead Btrfs developer Chris Mason.  Here is an excerpt from the webcast description:

‘Join Chris Mason, Director of Software Development at Oracle, the principal author of Btrfs flie system, and our own resident Linux kernel guru, as he discusses the development, features, benefits of the “Btrfs” file system (pronounced “Butter F S”, “B-tree F S”) in Linux.’

The video lasts about 1 hour and provides a very good overview of the current state of the file system, some of the pros and cons of Btrfs under various workloads, some of the features that have been implemented thus far, as well as some of the tools and features that a slated for future releases.

NPR developer talk at O’Reilly MySQL Conference and Expo 2010

Joanne Garlow one of the Senior developers here at NPR , will be giving a talk this Tuesday at the 2010 O’Reilly MySQL Conference and Expo in Santa Clara, CA.  The talk is entitled ‘Migration from Oracle to Mysql : An NPR Case Study’ and will focus on some of the ‘lessons learned’ during our recent Oracle to Mysql migration, it will also cover some of the tools that we found useful during the migration as well as some of the issues we encountered concerning character encoding and concurrency.

If you are thinking about converting your backend databases from Oracle to Mysql and you are attending this conference, you should attend this talk, as I am sure it will be very informative and quite helpful to you going forward.

Poor Write Performance with Oracle

We recently deployed an Oracle virtual machine for development and testing purposes. Imports and database migration scripts were taking several hours on existing VM’s, so we hoped this new machine with more RAM (32 GB) and more CPU horsepower (quad core Intel Xeon’s) would allow for those operations to move along much more quickly.

We soon got reports from users that this server was in fact much slower then the existing less powerful Oracle VM’s. After doing some poking around (with vztop) we discovered that there were no issues with cpu or memory resources, however the server was performing terribly when it came to I/O.

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