There are two excellent conferences going on this week, O'Reilly's Web 2.0 Conference November 7-9 in San Francisco and the MySQL Camp November 10-12 in Mountain View.  To be fair, I should say that MySQL Camp is really an "un-conference".  It's more of a participative event for hardcore MySQL users and developers than a traditional go-listen-to-someone-speak-and-drink-coffee-to-stay-awake type of conference.  So maybe that's the distinction: if you want to listen, go to Web 2.0, if you want to drive the discussion, go to MySQL Camp.  And there's no …

Yesterday we had our fourth MySQL User Group Meeting here in Hamburg. We had 19 attendees and a very informative talk about Ruby on Rails/Active record, held by Stefan Saasen. Thanks a lot, Stefan! It was quite insightful and we had good discussions and excellent food afterwards. I look forward to our next meeting, which I have already scheduled for February, 5th! So save the date and RSVP!

Some pictures of our meeting are in my Gallery, a PDF of Stefan's talk can be obtained from here. Enjoy and see you next time!

Yesterday we had our fourth MySQL User Group Meeting here in Hamburg. We had 19 attendees and a very informative talk about Ruby on Rails/Active record, held by Stefan Saasen. Thanks a lot, Stefan! It was quite insightful and we had good discussions and excellent food afterwards. I look forward to our next meeting, which I have already scheduled for February, 5th! So save the date and RSVP!

Some pictures of our meeting are in my Gallery, a PDF of Stefan's talk can be obtained from here. Enjoy and see you next time!

We are currently evaluating the consequences of migrating our application from Java 1.4 to Java 5. While initial tests revealed only simple issues (like variables called enum etc.) we are now seeing a much more severe problem: Random VM crashes.

Currently we only see this on Linux (Kernel 2.4) only, however even there we cannot reliably reproduce the problem. On a single machine we have seen two crashes in a week. Notably the application was not being used, it was just started and waiting for user input. Some background threads are running in this situation, however they do not do any work, either. They just poll some database tables for external changes, but there were none.

All of a sudden a VM would crash, leaving a hs_err_pid1234.txt behind. This is what they look like (shortened):

#
# An unexpected error has been detected by HotSpot Virtual Machine:
#
#  SIGSEGV (0xb) at pc=0x402989b9, …

We are currently evaluating the consequences of migrating our application from Java 1.4 to Java 5. While initial tests revealed only simple issues (like variables called enum etc.) we are now seeing a much more severe problem: Random VM crashes.

Currently we only see this on Linux (Kernel 2.4) only, however even there we cannot reliably reproduce the problem. On a single machine we have seen two crashes in a week. Notably the application was not being used, it was just started and waiting for user input. Some background threads are running in this situation, however they do not do any work, either. They just poll some database tables for external changes, but there were none.

All of a sudden a VM would crash, leaving a hs_err_pid1234.txt behind. This is what they look like (shortened):

#
# An unexpected error has been detected by HotSpot Virtual Machine:
#
#  SIGSEGV (0xb) at pc=0x402989b9, …

Another one of my coworkers announced his departure from the company today. That makes three of us in two weeks.

My last day is the 10th. I'll be spending the morning at Y! taking care of my final business. After that I'm heading over to MySQL camp over at the Google campus.

Right now a couple cop cars and lockheed martin security have some guy who was riding a bicycle on first ave. I have a feeling he wandered onto government property accidentally. Hopefully he doesn't get a trip to Guantanamo for it.

XenSource Announces High Performance Virtualization of Microsoft Windows and Linux Based on the Xen Hypervisor, XenSource (Press Release)

Simula Labs Launches Hosted Delivery Platform to Enable Enterprise Open Source Adoption, Simula Labs (Press Release)

Compiere Highlights Partner Achievements, Outlines Framework for Company and Product Direction for 2007, Compiere (Press Release)

Currenex Announces OpenSTP/FX Industry Initiative, Currenex (Press Release)

Alfresco Joins the ODF Alliance, Alfresco Software (Press Release) …

Anyone who's been to an open source conference this year has probably been to the Apress Publishing booth. If you have, undoubtedly, you've seen the yellow and black Apress buttons with the hysterical slogans on them. Myself, have a few Apress connections of my own, I have a few of my favorite ones at home, and the local PHP and Linux User Groups know the buttons because I pass them out when I go to the meetings. The buttons are the brilliant brainchild of Apress chief, Gary Cornell. Some of my favorite slogans:

• "I rarely come out of my shell environment"
• "Enter any 128 bit prime number to continue"
• "Do not offend the geeks, for they are the keepers of your passwords"

Julie Miller, from Apress, has volunteered to have buttons made for MySQL Camp, coming up this Friday through Sunday in …

Until recently, the MySQL databases I work with contain data that can be retrieved from other sources. Most of the data is either batched in from flat files or another database. It would be inconvenient to reload a couple months worth of data, but since these databases are not mission critical, the business could operate without them for a couple days. Lately, we've been implementing some semi-critical systems that rely on a somewhat expedient recovery.

The requirements for the project were that the database must remain up during the backup and losing a day's worth of data was acceptable. All of my regular Oracle readers are cringing at the moment, but hey, that was the rules I was working with.

My first thought was to use mysqlhotcopy because it backed up the actual physical files. However, mysqlhotcopy only allows you to backup MyISAM tables and we extensively use InnoDB.

My next choice was mysqldump. …