The latest from the MySQL community

So I have a constant battle with Charter Cable - high speed internet at home. Constantly causing all kinds of problems. So I decided to make a little script that runs from cron every minute that will track my outages in a single table database. Then I’ll be graphing the outages in real-time via jpGraph [as seen here]. Here’s the simple code.

The database table create script for router_uptime

CREATE TABLE `response` (
`id` bigint(32) NOT NULL auto_increment,
`state` tinyint(1) NOT NULL,
`ip_address` varchar(15) NOT NULL,
`Creation_time` datetime NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=3833 ;

The Script

#-(0)> cat check_ping
#!/bin/sh
…

For several years I have been wondering if there was a RDBMS that serves as a message queue as well1. And in the end of last year, noticing that MySQL 5.1 with support for pluggable storage engine was entering its RC stage, and that (from little googling) nobody was creating such storage engine, I dicided to write my own.

Q4M (Queue for MySQL) is a message queue that works as a pluggable storage engine of MySQL 5.1, designed to be robust, fast, flexible. The development started in late December of 2007, and although it is very primitive, operates quite swiftly.
q4m.31tools.com

Yes, it is primitive, and might have stability problems (I do not recommend using Q4M in a production environment), but if you are interested, please have a try.

1: At least Oracle seems to, but I never had a chance to use it.

The latest release of DBD::Oracle is now ready and can be found at: CPAN DBD::Oracle. It is a Perl module that works with the DBI module to provide access to Oracle databases. It is maintained by me, John Scoles as open source/free software, under the auspices of The Pythian Group. The release has been fully tested [...]

Fast arrays, wild women, crazy nights… and database access times to disk based files. Here are some results from various dev servers I have.

 2x 147GB SCSI U320 drives in hardware RAID-1
#-(root@sunfire)-(/home/user)-#
#-(0)> hdparm -t /dev/mapper/VolGroup00-LogVol00
Timing buffered disk reads:  172 MB in  3.02 seconds =  56.93 MB/sec
#-(0)> hdparm -T /dev/mapper/VolGroup00-LogVol00
Timing cached reads:   1450 MB in  2.00 seconds = 724.77 MB/sec

2x 10GB SCSI U160 disks in software RAID-1
#-(root@sgi)-(~)-#
#-(0)> hdparm -t /dev/md0
Timing buffered disk reads:   36 MB in  3.19 seconds =  11.28 MB/sec
#-(0)> hdparm -T /dev/md0
Timing cached reads:   306 MB in  2.00 seconds = …

While some colleagues have already arrived in Orlando to meet fellow MySQLers, my plane from FRA to MCO (via DTW) does not leave until 10:20am tomorrow. Currently I am staying at my parents' place in Heidelberg, from which I will be picked up by an airport shuttle service early tomorrow morning (5:40am, ugh!).

I am looking forward to meeting with the other members of my team as well as old and new colleagues from the different departments. There seems to be some kind of outdoor team building event taking place on Wednesday afternoon - we have been split up into mixed groups and were asked to bring comfortable clothes and a light sweater or jacket. I hope I am not too jetlagged by the end of the day...

This will be my fourth MySQL staff meeting - when I joined the company in 2002, I was lucky to attend the third staff meeting in St. Petersburg, Russia right during the first week when I started my new job. Back then, we …

… is coming soon. We were just about to release beta 5.0.12 out into the wild on friday, but it looks as if it wasn’t meant to be. I found some nasty issues in the latest fixes we did, so we had to correct those before we can set it free.

Again many bugs have been fixed since version 5.0.11 so stay tuned for the upcoming new release.

Listening to many recruiters and hiring managers talk about how difficult it is to find MySQL certified professionals, I've created a MySQL Certified Professionals group on LinkedIn. What is LinkedIn? LinkedIn is an online network of more than 17 million experienced professionals from around the world, representing 150 industries.

This MySQL group is only for certified professionals, technical recruiters, hiring managers or human resource managers to help locate MySQL Certified Professionals in your area. If you have any of the MySQL certifications, you can sign up on LinkedIn. You need to email me your MySQL ID and public password to verify your certification on the MySQL website. If you're a recruiter, hiring manager or human resources professional you can also join this …

Here for the MySQL All Company Meeting. Arrived okay… albeit late (got to stop in two cities I didn’t intend to). Had breakfast with Monty, Monty and Giuseppe and a few cups of coffee later… it sorta feels like morning.

My world tour includes mostly warm places (Orlando, Los Angeles, Australia, Singapore), but to cover the first leg, Munich, I needed warm clothes (cover is the operative word here).
Thus, when I saw a skilled craftsman creating customized hats and scarfs, I couldn't resist.
The weather in Orlando does not require such gear. This is a view form my hotel room.
. We are going to have MySQL company meeting in this beautiful place. For now, I am just nursing my jet lag and preparing to meet a few hundred colleagues.

mysql-5.0.51 causes huge blocking locks under high load.

It also causes relay-log corruptions. For instance, how can a syntax error make it into replication, the reason is mysql-5.0.51 is truncating the stream.

The only work around is to rebuild the relay log.

The BUG is listed here for replication problems. I suspected IO_CACHE corruption as the cause.



update: this is the cause of the huge blocks

InnoDB: Warning: a long semaphore wait:
--Thread 1173899616 has waited at btr0cur.c line 424 for 292.00 seconds the semaphore:
S-lock on RW-latch at 0x2df5159f58 created in file buf0buf.c line 497
a writer (thread id 1173899616) has reserved it in mode  exclusive
number of readers 0, waiters flag 1
Last time read locked in file btr0cur.c line 424
Last time write …