So I spent several hours over the last few days on the Secondary index bug. Out of frustration I decided to try and bypass the LRU concept all together and try going to a true secondary page cache. In standard Waffle a page is written to memcached only when it is expunged ( or LRU’d ) from the main buffer pool. This means anything in the BP should not be in memcached. Obviously with this approach we missed something, as Heikii pointed out in a comment to a previous post, it seems likely we are getting an old version of a page. Logically this could happen if we do not correctly expire a page on get or we bypass a push/lru leaving an old page in memcached to be retrieved later on.

So I was thinking why not bypass the LRU process? While I feel this is the most efficient way to do this, its not the only way. I modified innodb to use the default LRU code and then modified the page get to push to memcached on any disk read. Additionally I added …

Dear Kettle friends,

Will Gorman and Mike D’Amour, Senior Developers at Pentaho, are presenting Pentaho’s Google integration work at the Google I/O Developer Conference. (at the Sandbox area to be specific)   Yesterday, Pentaho announced that much.

Here are a few of the integration points:

• Google maps dashboard (available in the Pentaho BI server you can download)
• A new Google Docs step was created for Pentaho Data Integration Enterprise Edition
• Running (AVI, 30MB) the …

Writing small volume of data (Bytes-MBs) with sync (fsync()/fdatasync()/O_SYNC/O_DSYNC) is very common for RDBMS and is needed to guarantee durability. For transactional log files, sync happens per commit. For data files, sync happens at checkpoint etc. Typically RDBMS does syncing data very frequently. In this case, overwriting is much faster than appending for most filesystems/storages. Overwriting does not change file size, while appending does. Increasing file size requires a lot of overheads such as allocating space within the filesystem, updating & flushing metadata. This really matters when you writes data with fsync() very frequently. The following are simple benchmarking results on ext3 RHEL5.3.


1. creating an empty file, then writing 8KB 128*1024 times with fdatasync()
fdatasync per second: 3085.94321
(Emulating current binlog (sync-binlog=1) behavior)

2. creating a 1GB data file, then …

Following the launch of the Open Database Alliance a number of interesting reports were published that examined its role in establishing MariaDB as an alternative development branch for MySQL and as a vendor-neutral open source database collective.

I had a few questions myself, which Monty Widenius and Peter Zaitsev, CEO of Percona, were good enough to answer for me via email. They also agreed for the exchange to be published here. This is what they had to say:

Q: Monty has stated that the intention is to open up the Alliance to include other open source database projects - any indication of how this would be done given the diverse …

We’re proud to announce the availability of the 2nd alpha-version of MSQL Workbench 5.2. As you may already know, this is the youngest member of the workbench-family and also the version that adds another role - the one of the database-querying-tool - to the application. There have been major enhancements - not only to the querying part - since we released the first alpha version. Please keep in mind that this is still an alpha version and it’s not recommended for use in a production environment. While most parts of the final application are already in place there are still a few things left to implement or details subject to change. Please download the program, take it for a test-drive and tell us what you think.

Source code and binary packages of MySQL Workbench 5.2.1 OSS for Windows, Mac OS X Leopard and some Linux distributions are freely available for download at:

…

First there was LAMP.  But are you using GLAMMP?  You have probably not heard of it because we just coined the term while chatting at work.  You know LAMP (Linux, Apache, MySQL and PHP or Perl and sometimes Python). So, what are the extra letters for?

The G is for Gearman - Gearman is a system to farm out work to other machines, dispatching function calls to machines that are better suited to do work, to do work in parallel, to load balance lots of function calls, or to call functions between languages.

The extra M is for Memcached - memcached is a high-performance, distributed memory object caching system, generic in nature, but intended for use in speeding up dynamic web …

Following on the heels of our memcached performance tests on SunFire X2270 ( Sun's Nehalem-based server) running OpenSolaris, we ran the same tests on the same server but this time on RHEL5. As mentioned in the post presenting the first memcached results, a 10GBE Intel Oplin card was used in order to achieve the high throughput rates possible with these servers. It turned out that using this card on linux involved a bit of work resulting in driver and kernel re-builds.

• With the default ixgbe driver from the RedHat distribution (version 1.3.30-k2 on kernel 2.6.18)), the interface simply hung during the benchmark test.
• This led to downloading the driver from the Intel site (1.3.56.11-2-NAPI) and re-compiling it. This version does …

Following the launch of the Open Database Alliance some people have assumed that it is only a matter of time before MariaDB becomes the de facto replacement for MySQL.

That assumes that Oracle will allow the development of MySQL to stagnate, either deliberately or through neglect - something that we have expressed our doubts about, but even if that were the case it appears that the GPL (or more to the point MySQL’s dual licensing strategy) may restrict the potential for MariaDB.

Curt Monash recently raised the question of whether closed-source storage engines can be used with MySQL (and, by …

Following on the heels of our memcached performance tests on SunFire X2270 ( Sun's Nehalem-based server) running OpenSolaris, we ran the same tests on the same server but this time on RHEL5. As mentioned in the post presenting the first memcached results, a 10GBE Intel Oplin card was used in order to achieve the high throughput rates possible with these servers. It turned out that using this card on linux involved a bit of work resulting in driver and kernel re-builds.

• With the default ixgbe driver from the RedHat distribution (version 1.3.30-k2 on kernel 2.6.18)), the interface simply hung during the benchmark test.
• This led to downloading the driver from the Intel site (1.3.56.11-2-NAPI) and re-compiling it. This version …

Following on the heels of our memcached performance tests on SunFire X2270 ( Sun's Nehalem-based server) running OpenSolaris, we ran the same tests on the same server but this time on RHEL5. As mentioned in the post presenting the first memcached results, a 10GBE Intel Oplin card was used in order to achieve the high throughput rates possible with these servers. It turned out that using this card on linux involved a bit of work resulting in driver and kernel re-builds.

• With the default ixgbe driver from the RedHat distribution (version 1.3.30-k2 on kernel 2.6.18)), the interface simply hung during the benchmark test.
• This led to downloading the driver from the Intel site (1.3.56.11-2-NAPI) and re-compiling it. This version …