This is part 3 in my RAMSan Series.

While I am confident the read-only test was a reasonably good test ( I just needed to push more ), my mixed load test was marred by issues.  It was really a quick attempt to get a heavy read/write workload.  I ran into issues with how I wrote this so I will spare you the details.  Some flash devices are notoriously poor performing in writes, so its important to at least briefly look at this.  What I will share are the IOPS & latency numbers from this test.  The mixed workload does updates & selects at this point, these are a mix of PK updates, secondary index updates, etc.  These typically are built to run faster and smaller the the read-only IO bound workload.

By the 11th interval the Ramsan was pretty much complete.  The peaks are whats interesting…  lets look at this in a slightly different way.

So in the admittedly flawed mixed workload I am …

This is part 2 of My RAMSan Series.

In my normal suite of benchmarks I typically run dbt2 & sysbench oltp benchmarks next…  and I did run then, but to be honest they just weren’t that interesting.  They showed an improvement over my intel ssd results I ran on frankenmatt,  but it was difficult to provide an apples to apples comparison.   The server hardware was way different ( cpu, memory, controller, etc ).  Plus I typically run a test -vs- non-flash then a test with flash, and ran tests with varying degrees of memory… the test box had 2GB of memory and sparse internal disk, so my normal test cycles were already in jeopardy.  For what I ran   I was pushing CPU limits long before I was hitting the IOPS I saw above.  In fact in a 100W test I ended up peaking @ 1200 iops, while the CPU was @ 100%.

The challenge is building an effective solution that will easily maximize MySQL …

Well its about time I posted this:)  This is part 1 of 3 in my Ramsan series.

For those who have paid attention to my blog, know I love talking  IO!  I also love performance.  Absolutely love it.  Love disk, disk capactiy, io performance, solid state..  So as I march towards my UC session on MySQL Performance on Solid State Disk my goal is to try and test as many high end solid state disk systems as possible.  All the vendors have been great, giving me access to some really expensive and impressive toys.  I finished up testing Texas Memory System’s flash appliance the RamSAN 500 this week and wanted to post some numbers and some thoughts. TMS makes RamSAN appliances that merge disk and RAM into a really fast SANS.     First I go a ways back with TMS, I deployed and Oracle Rac installation on one of their …

InitMarketing has made its calendar of world-wide conferences and trade fairs related to Free and Open Source Software, IT and specific industries available to the public.

It currently includes 122 events in 17 countries taking place in 2009. 43 of them in Germany, 69 in USA. We use this calendar when planing events for our customers, thus we’ll regularly update it. Please let us know of any events which are not on our radar yet by commenting to my blog or commenting at the bottom of the events page.

A very special 5 minute DBA post here, we are crossing over… sys admin & dba oh my! I tend to always look first at the OS, and then move over to looking at what is going on inside the database. So if you have five minutes to look at the OS, what do you look for? What tools do you use? What gotchas are their?

First Everyone should be familiar with top. This is a great tool and place to start.

It is well known that MySQL can use a lot of temporary files and that, using a ramdisk (tmpfs on Linux) can improve performance drastically as Matt has shown here. The problem with tmpfs is its limited size. You need just one query creating a huge temporary file that happens once per day to screw up the tmpfs scenario. I have done some fuse programming in my previous job and I think it is possible to use fuse to mix a tmpfs filesystem with a regular filesystem, the regular filesystem being used only when the tmpfs is full. Fuse has a lower performance level than a regular filesystem but I think the possibility to use tmpfs the vast majority of the queries needing a temporary file will overcome the performance limitation of fuse.

That is the explanation for the MiniWheatFS name, the frosted side is the tmpfs and the healthy side is the regular filesystem. There are many fuse …

One might have thought Microsoft was back rattling the patented software sabres against Linux and open source this week, reading some of the recent reports regarding Redmond’s patent infringement suit against automotive navigation and GPS player TomTom. However, upon further review, it seems that Microsoft is making a point to say that these suits are not aimed at the Linux OS or open source. In response to my own query, the company offered this:

First, to answer your earlier question on how the suit with TomTom involves the Linux Operating System, three of the infringed patents read on the Linux kernel as implemented by TomTom. However, open source software is not the focal point of this action. …

Shortly after I blogged about my upcoming talks and events, I got informed that one of my session proposals for the next09 conference was accepted. This event will take place in Hamburg, Germany on Tuesday and Wednesday (5th and 6th of May), so at least there isn't much travel involved.

My talk about "Working for a Virtual Company: How we do it at MySQL" has been scheduled for 9:00 am on Wednesday morning, parallel to a keynote by Brian Solis from FutureWorks. I'm not sure how many people will actually show up, but I look forward to giving a talk about a less …

This neat one line command can be of interest when you are rebuilding a MySQL slave and replication is currently catching up.

$ watch --interval=1 --differences 'mysql -uuser -ppassword -e "show slave status\G"'

You will see the standard SHOW SLAVE STATUS output, but the watch command presents an updated view every second, and highlights differences. This can be useful in a background window to keep an eye on those ‘Seconds Behind Master’.

*************************** 1. row ***************************
             Slave_IO_State: Waiting for master to send event
                Master_Host: 10.10.10.10
                Master_User: slave
                Master_Port: 3306
              Connect_Retry: 60
            Master_Log_File: mysql-bin.000626
        Read_Master_Log_Pos: 88159239
             Relay_Log_File: slave-relay.000005
              Relay_Log_Pos: 426677632
      Relay_Master_Log_File: mysql-bin.000621 …

My calendar for the upcoming months is already filling up with conferences, trade fairs and other events at which I'll speak about MySQL. Here's a quick overview:

• This coming Thursday at 15:00 CET, I'll be speaking about "Backing up MySQL using file system snapshots" at the MySQL University. The session will be hosted live using DimDim, which is a great online conferencing and presentation system (Flash required). Attendance is free, so come and join me if you want to learn more about this backup technique!
• On Friday, 6th of March at 15:15 I'll give a presentation about "MySQL Backup and Security" in the …