Now that MySQL 5.5 is in RC, I decided to have a look at the semi synchronous replication. It’s easy to get going, and from my very initial tests appear to be working a treat.

This mode of replication is called semi synchronous due to the fact that it only guarantees that at least one of the slaves have written the transaction to disk in its relay log, not actually committed it to its data files. It guarantees that the data exists by some means somewhere, but not that it’s retrievable through a MySQL client.

Semi sync is available as a plugin, and if you compile from source, you’ll need to do –with-plugins=semisync….
So far, the semisync plugin can only be built as a dynamic module, so you’ll need to install it once you’ve got your instance up and running. To do this, you do as with any other plugin:
install plugin rpl_semi_sync_master soname …

Now that MySQL 5.5 is in RC, I decided to have a look at the semi synchronous replication. It’s easy to get going, and from my very initial tests appear to be working a treat.

This mode of replication is called semi synchronous due to the fact that it only guarantees that at least one of the slaves have written the transaction to disk in its relay log, not actually committed it to its data files. It guarantees that the data exists by some means somewhere, but not that it’s retrievable through a MySQL client.

Semi sync is available as a plugin, and if you compile from source, you’ll need to do –with-plugins=semisync…. So far, the semisync plugin can only be built as a dynamic module, so you’ll need to install it once you’ve got your instance up and running. To do this, you do as with any other plugin:

1
2

      install plugin …

Now that MySQL 5.5 is in RC, I decided to have a look at the semi synchronous replication. It’s easy to get going, and from my very initial tests appear to be working a treat.

This mode of replication is called semi synchronous due to the fact that it only guarantees that at least one of the slaves have written the transaction to disk in its relay log, not actually committed it to its data files. It guarantees that the data exists by some means somewhere, but not that it’s retrievable through a MySQL client.

Semi sync is available as a plugin, and if you compile from source, you’ll need to do –with-plugins=semisync…. So far, the semisync plugin can only be built as a dynamic module, so you’ll need to install it once you’ve got your instance up and running. To do this, you do as with any other plugin:

1
2

      install plugin …

Looks like 2010 is the year of multiplication in HeidiSQL: Some months ago I had implemented multiple query tabs. Then, each query tab became capable of displaying multiple results in subtabs. And now, we finally have multiple connections in the database tree. Thanks to monkeilas for constructive suggestions.

I recently worked on upgrading MySQL from one of very early MySQL 5.0 versions to Percona Server 5.1. This was a classical upgrade scenario which can cause surprises. Master and few slaves need to be upgraded. It is a shared database used by tons of applications written by many people over more than 5 years timeframe. It did not have any extensive test suite we could use for validation. As you might guess in such cases some of the original authors have moved on and nobody is exactly sure what application does or does not do with the database. Database is production critical with serious role in serious company so we can't just do a reckless upgrade

First we needed to do a sanity check on existing replication setup. As we're checking replication consistency down the road we need to make sure replication is in sync to begin with to avoid false …

Dear Kettle friends,

As mentioned in my previous blog post, copies of our new book Pentaho Kettle Solutions are finally shipping.  Roland, Jos and myself worked really hard on it and, as you can probably imagine, we were really happy when we finally got the physical version of our book in our hands.

So let’s take a look at what’s in this book, what the concept behind it was and give you an overview of the content…

The concept

Given the fact that Maria’s book, called Pentaho Data Integration 3.2, …

Lately we have been especially enjoying the opportunities that Poor Man’s Profiler provides us – but also the technology has improved a lot too – there have been few really useful mutations.

One mutation (hyper-pmp) was Ryan Mack’s approach of having somewhat more efficient sampling – instead of firing gdb each time, he instructed gdb to get backtraces every time monitored process gets a signal (SIGUSR2 for example). This allows to maintain a persistent debugger attachment – and then signal periodically to get stacks analyzed.

Other mutation was auto-pmp – high frequency polling of process state (e.g. how many threads are running), and when a certain threshold is exceeded – obtaining stacks for further analysis (this combines …

Patents! Patents! Patents! Canonical’s perfect 10. And more.

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca, and daily at Paper.li/caostheory
“Tracking the open source news wires, so you don’t have to.”

# Google responded to Oracle’s claims that its Android OS infringes copyrights and patents related to Java.

# Matt Asay evaluated the various patent claims against Android and its related devices.

# Microsoft licensed smartphone patents from ACCESS Co and a subsidiary of Acacia Research.

# Glyn Moody …

OpenSQLCamp Boston 2010 happens 16-17 October 2010, at MIT in Boston (there is an evening social session on Friday the 15th as well). Its organised by MySQL community aficionado Sheeri Cabral, and by looking at the schedule and sponsors, it is going to be one of the most diverse OpenSQLCamp’s by far.

Monty Program is a sponsor, and I (Colin) will be participating on behalf of Monty Program to bring some information about what’s new from the Istanbul company meeting. More of the company certainly wanted to be at the event, but most are going to be spending some quality vacation time in Istanbul, since our all company meeting only ends on the 12th.

If you have not already registered to attend, what’s keeping you? Its free to attend, and Sheeri tells me that there’s some very cool schwag available for grabs.

Enable MyISAM Auto-Repair

MyISAM can be configured to check and repair its tables automatically. By enabling the MyISAM auto repair you let the server check each MyISAM table when it is opened. It checks  if the table was closed properly when it was  last used, also checks if it needs any repair, if required it repairs the table.

To enable auto check and repair,you can start the server with –myisam-recover with following options.

DEFAULT for the default checking.

BACKUP tells the server to make a backup of any table that it must change.

FORCE causes table recovery to be performed even if it would cause the loss of more than one row of data.

QUICK performs quick recovery: Tables that have no holes resulting from deletes or updates are skipped.

You can also add it to the my.cnf file as shown below

[mysqld]

myisam-recover=FORCE,BACKUP

-Thanks …