There are a few posts i have missed. Lots have happened in the mean time...






Have been to home and to my collegues marriage on 14th of may to bhopal. Had a wonderful day on 15th of may at the famous lake of Bhopal. Had lunch at a four-star, did boating, hung around in odd clothes... In all had great fun. Below are some pics from the same...

The clothes were bought specially for the occassion. We had people enquiring "Where have we come from?". Hope we would have created some waves...

Secondly …

Pro MySQL 5 from Jay Pipes and Mike Kruckenberg is definitely one of the best advanced MySQL books around.

dbazine.com has published a Podcast Episode with an interview with Jay and Mike where they talk about themselves and - of course - MySQL:

http://www.dbazine.com/podcasts/podcast-kruckenberg

Sun just post SpecjAppserver2004 with a very excellent result of 712.87 SPECjAppserver 2004 JOPS@Standard using the latest SJSAS 9.0 Platform Edition on Sun Fire X4100 Cluster with MySQL 5.0.20 yesterday(Also check out Tom Daly's blog, Scott Oak's blog and Robert Lee's blog for more information)

SPECjAppserver is industry standard benchmark for performance testing J2EE application server. As part of important component of SPECjAppserver testing, database's performance and scalability also greatly affect the overall performance result in …

My dual opteron which has gobs (more then 2gigs) of memory will not let a single process spawn more then 12,000 threads at any time.

Well, somewhere between 12,000 and 13,000 threads things go haywire. I had a program I put together yesterday break because it was let loose with thread creation. So last night I wrote a little loop around an application just to see where consistent thread creation could occur (each thread did nothing more then maybe sleep for a second (it had a one in seven chance of the sleep event occurring)).

I am sure there is a system limit I am ignoring, but I wanted to see what the practical numbers where in this case.

Completely random and probably worthless information :)

Its crazy to generate this many threads in the first place. I saw Nusphere once do this with Gemni to prove a point about concurrency, but it didn't prove much of a point for me since I thought …

Sun just post SpecjAppserver2004 with a very excellent result of 712.87 SPECjAppserver 2004 JOPS@Standard using the latest SJSAS 9.0 Platform Edition on Sun Fire X4100 Cluster with MySQL 5.0.20 yesterday(Also check out Tom Daly's blog, Scott Oak's blog and Robert Lee's blog for more information)

SPECjAppserver is industry standard benchmark for performance testing J2EE application server. As part of important component of SPECjAppserver testing, database's performance and scalability also greatly affect the overall performance result in …

Sun just post SpecjAppserver2004 with a very excellent result of 712.87 SPECjAppserver 2004 JOPS@Standard using the latest SJSAS 9.0 Platform Edition on Sun Fire X4100 Cluster with MySQL 5.0.20 yesterday(Also check out Tom Daly's blog, Scott Oak's blog and Robert Lee's blog for more information)

SPECjAppserver is industry standard benchmark for performance testing J2EE application server. As part of important component of SPECjAppserver testing, database's performance and scalability also greatly affect the overall performance result in …

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 it).
In 5.1 I implemented a new feature: memory mapping for the datafiles. That can be enabled by --myisam_use_mmap=1 startup option.
In this case instead of systems call MyISAM will use memcpy function. There is a memory addressing limit for 32bit platforms - 2Gb, so the datafiles over 2GB will be used the old way - pread/pwrite functions. Mmap is available on all POSIX-compatible platforms. It will work faster for SELECT/UPDATE/INSERT inside file queries, and no performance gain (maybe a bit slower) for INSERT at the end of file. In case with INSERT at the end of file we have …

SNORT developer Sourcefire closed a $20 million Series D round of venture capital led by late-stage specialist Meritech Capital Partners of Palo Alto, Calif., to boost its balance sheet and position the company for an initial public offering as early as the end of this year.

Will Sourcefire IPO before MySQL?

Link: Sourcefire gets second wind

In this article I’ll show several ways to emulate a FULL OUTER join on a RDBMS that doesn’t support it, as is the case with even the most recent versions of MySQL. This useful query is surprisingly tricky to get right. Introduction A standard SQL FULL OUTER join is like a LEFT or RIGHT join, except that it includes all rows from both tables, matching them where possible and filling in with NULLs where there is no match.

If you’re not using replication, the only thing you have to worry about is MyISAM and InnoDB performance. There are a lot of things you can easily do to get more (or less!) performance out of either of them. So, you get your system tuned and handling 1500 updates per second, easy as pie. You’ve got a single IDE, SATA, or SCSI disk, or maybe two using software RAID.

Then, due to natural progression, needed scalability, or catastrophic failure, you realize that you should probably be using replication, so that you can have more than one of these systems working at once.

The first step in setting up replication is normally to turn on binary logging (by enabling log-bin) on the future master. This ensures that every change to the database is logged so that it can be sent to your future slaves and executed there. Here, though, you find your first obstacle.

You enable binary logging, and all of the sudden, performance goes …