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 …

O_DIRECT under high load causes these issues

This is a symptom

Losing some ticks... checking if CPU frequency changed.
warning: many lost ticks.
Your time source seems to be instable or some driver is hogging interrupts
rip __do_softirq+0x4d/0xd0
ttyS1: 1 input overrun(s)
ttyS1: 1 input overrun(s)
ttyS1: 1 input overrun(s)
ttyS1: 1 input overrun(s)
ttyS1: 1 input overrun(s)



BUT THE REAL PROBLEM is it Locks up the partition that the ibdata file is on.


Systems where the server locked up.

2.6.9-34.ELsmp #1 SMP Fri Feb 24 16:56:28 EST 2006 x86_64 x86_64 x86_64 GNU/Linux

          total       used       free     shared    buffers     cached
Mem:      16412760   16389976      22784          0      82440     686368
-/+ buffers/cache:   15621168     791592
Swap: …

This will be one of those posts I’d like to publish primarily to be able to coma back later and check it out instead of reading docs again

So, we have a server with two (or more) network interfaces are we need to be able to use more than one interface in our VDS machines. How do we set it up?

(more…)

Last week, Benchmark announced a $3.5 million investment in Engine Yard, which provides commercial support for Ruby on Rails applications. Engine Yard is doing $3 million in business and growing. It's also profitable. It didn't need the investment.

The investment, however, is very telling. When one of the top venture capital firms on the planet puts hard dollars behind a support model, it's significant. It becomes doubly so when the firm (or its investors) in question previously invested in JBoss, MySQL, SpringSource (Interface21), and other support-based open-source companies.

It may mean that Benchmark knows something that the rest of the industry seems determined to ignore: services-based businesses may well be the future of the software industry.

...

One of Mitt Romney's sons used to be my neighbor. As such, it was hard to not contribute to the campaign.

I'm finding, however, that it's even harder to disengage from the campaign. I get four emails per day (sometimes more) from the campaign (usually two of the same message sent to the two email addresses of mine they somehow have on file). I get calls. I can't get away. Dana calls it basic database marketing. I call it annoying.

It's a bit like the traditional proprietary software model, where obnoxious sales people sit in your office haranguing would-be buyers until you purchase the proprietary ball-and-chain to get rid of the salesperson. (Which is exactly what happens when you write the check - the salesperson disappears. Completely.)

Today I found myself pining for an open-source political campaign. It would operate something like this:

…

A couple of days ago, Jacob DeHart and Harper Reed pinged me with an interesting idea for a MySQL storage engine. A "write-only" engine into a Bloom Filter.

What a neat idea!


The bloom filter, and it's varients and improvements, is almost magic. You can insert items. You can tell if you have inserted an item in the past, You can tell if you havn't inserted an item in the past (probably). But you can't get a list of all the items inserted.

And the performance is interesting. The space used is fixed. Insert and lookup time is constant.


CREATE TABLE t (v VARCHAR(255)) MAX_ROWS=100 ENGINE=BLOOM;

Have to specify about how many elements it will hold.

It …