Recently with a client while running a number of disaster recovery tests I came across a nasty situation which was not part of the original plan and provided a far worse disaster situation then expected.

I should preface this condition with some of the environment conditions.

• MySQL 5.0 Enterprise 5.0.54
• RHEL 5 64bit
• Master and 2 Slaves
• MySQL Data and MySQL Binary Logs/MySQL Error Logs are on separate disk partitions

While running stress tests under high load, we tested the filling of partition containing the logs. This partition included the binary log and MySQL error log.

The observed output was.

• An error message was written to the MySQL error log. See below.
• Application throughput dropped, but did not stop.
• Binary logs stopped occuring.
• MySQL proactively stopped logging but continued to process …

As I had written earlier in Understanding InnoDB MVCC, I am trying to understand why InnoDB is taking a lock on data during an UPDATE when I do not expect this to happen.

Not wanting to go looking at the InnoDB source code to understand the problem, I’m endeavouring to possibly use existing MySQL monitoring to try and understand the problem better. In this case, I’m going to investigate SHOW ENGINE INNODB STATUS first. An old but still relevant article for reference is SHOW INNODB STATUS walk through. The MySQL High Performance book is also a good starting reference.

I’ve just installed 5.1.36 on a new Linux 64 bit laptop for this test.

For now all I’ve done is ensure the innodb_buffer_pool_size is sufficient …

Funding for Aptana and Jolicloud. Ingres targets MySQL. Trent Reznor on Open Core (sort of). And more.

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Funding
# Aptana raised $7.8m in funding from Rembrandt Venture Partners and Accel Partners.

# Jolicloud raised $4.2m in series A funding for a Linux-based Netbook OS.

Not with a bang…
# Sun reported preliminary revenues for Q4 2009 of $2.58bn to $2.68bn, compared to $3.78bn a year ago.

Best of the rest
# Ingres …

The MySQL KILL command as the name suggests kills queries that are running.

After identifying the Id using the SHOW PROCESSLIST command, the User of the connection/thread or a database user with SUPER privileges can execute KILL [id]; to remove the connection/thread.

However, there is an ability to kill just the query that is being executed rather the entire connection. The default when not specified is to kill the connection, however you can optional specify the CONNECTION or QUERY keywords.

For example, below is an interactive test.

Thread 1:

mysql> select sleep(10);

Thread 2:

mysql> show processlist;
+----+------+-----------+------+---------+------+-----------+------------------+
| Id | User | Host      | db   | Command | Time | State     | Info             | …

This post builds upon the earlier article (Creating a simple Cluster on a single LINUX host) which explained how to install and run a Cluster where all of the nodes run on the same physical host.

The single host solution is not great for a real deployment – MySQL Cluster is designed to provide a High Availability (HA) solution by synchronously replicating data between data nodes – if all of the data nodes run on a single host that that machine is a single point of failure.

MySQL Cluster running accross 2 hosts

This article demonstrates how to split the nodes between hosts; the configuration will still be fairly simple, using just 2 machines but it should be obvious how to extend it to …

So i got the T1000 working again (finally, after much screwing about trying to get the part). I then hit the ever annoying “no console” problem, where the console didn’t work – kind of problematic.

After a firmware upgrade, and passing “console=/dev/ttyS0″ to the kernel, things work.

So the T1000 firmware 6.3 doesn’t work with modern debian kernels. Thing swork with 6.7 though.

Microsoft makes a patent promise. JBoss is certifiable. And more.

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# Microsoft announced that it will be applying its Community Promise to the ECMA 334 (C#) and ECMA 335 (CLI) specifications, reducing patent concerns related to Mono.

# Red Hat achieved EAL 2+ security certification for JBoss Enterprise Application Platform.

# A European Commission white paper on standards stirred some controversy with regards to open source. …

There has been no shortage of lively discussion on open source software licenses with recent shifts in the top licenses, perspectives on the licenses or lack of them for networked, SaaS and cloud-based software, increased prominence of a Microsoft open source license and concern over the openness (or closedness, depending on your perspedtive) of the latest devices. Amid all of it, we’re pleased to present our latest long-form report, CAOS 12 - The Myth of Open Source …

I've now posted all the current talk submissions to the OpenSQL Camp Wiki. A big Thank You to everyone who contributed so far and helped us to bang the drum for this event! If you haven't heard about OpenSQL Camp yet, it's a subconference of the Free and Open Source Conference (FrOSCon) in St. Augustin, Germany, which takes place on August 22+23. The topic of OpenSQL Camp is "Open Source databases and related technologies" and we're looking for interesting presentations in this field.

As we have 12 session slots to fill, we still have room for at least 6 more submissions! It's also a tad bit MySQL-centric at the moment, that should definitely change! We would love to get some more diversity to cover a broader range of Open Source Database technology.

So please submit your talk proposals and help …

Governments. Governance. Customers wins. And more.

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Governments
The Examiner provided a two part interview with Daniel Risascher, Office of the CIO, Department of Defense, on open source at the DoD, while Government Technology Magazine reported on how open source software and cloud computing can save government money. Similarly, The UK Conservative party delivered a paper on the future of open standards, open source, SOA and cloud for UK Government, while it was reported that Vienna to …