This Thursday (October 22nd, 13:00 UTC), Walter Heck (of Open Query) will present Dual Master Setups With MMM. MMM (Multi-Master Replication Manager for MySQL) is a set of flexible scripts to perform monitoring/failover and management of MySQL master-master replication configurations (with only one node writable at any time). Session slides (PDF).

The toolset also has the ability to read balance standard master/slave configurations with any number of slaves, so you can use it to move virtual IP addresses around a group of servers depending on whether they are behind in replication. For more
information, see mysql-mmm.org.

For MySQL University sessions you point your browser …

At the beginning of 2009, I was hired by Tag1 Consulting as Jeremy Andrews' full time partner. A decidedly questionable decision on his part, but a great change for me! I used to work at the Open Source Lab at Oregon State University and I am currently the sysadmin for drupal.org. Working at the OSL and drupal.org spoiled me, I'll be completely honest about that. I got used to working with interesting new technologies and consistently pushing the limits of my knowledge.

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Before a monitoring and notification system for MySQL (and other infrastructure) can be fully conceived, a variety of questions must be asked. I’ve attempted to put some of the most important of them together in this post.

These are what I feel are some best practice recommendations.



#1 Define what is to be monitored.

• 
  
• Is it a HOST?
  
• Is it a SERVICE?
  

#2 Determine what level of health monitoring is desirable.

• 
  
• Basic Monitoring Probes (typically active checks)
  
  • 
    
  • Simple TCP/IP port up/down
    
  • Disk space, free memory, swap utilization, etc
    
  • File exists (or does not exist, or is not of at least X size)
    
  …

Here is the list of errors I have faced while importing a 25G .sql file into my cluster setup.
This is a test setup and to get maximum RAM availability, I have 3 data nodes and 1 Management node with replication factor of 1. The solutions provided are the ones which helped me.


1. ERROR 1297 (HY000) at line 1872: Got temporary error 410 'REDO log files overloaded, consult online manual (decrease TimeBetweenLocalCheckpoints, and|or incre' from NDBCLUSTER
Solution : Modify / Add parameter TimeBetweenLocalCheckpoints in your config.ini.
Default value = 20
Changed it to TimeBetweenLocalCheckpoints =6 Setting TimeBetweenLocalCheckpoints to 6 or less means that local checkpoints will be executed continuously without pause, independent of the cluster's workload.
2. ERROR 1297 (HY000) at line 1443: Got temporary error 1220 'REDO log files overloaded, consult …

Hello folks, we have just released another alpha-version of MySQL Workbench 5.2. This release now contains another couple of Administration features like “Managing your user accounts”, “Viewing your log tables”, improved start/stop scripts for remote administration (administration of remote servers is working in the mac and linux version of MySQL Workbench 5.2.6 – the windows version needs yet a bit more tweaking on that park, so that will be available in next release). Please note that 5.2.5 was an internal only release.

Head right over to our download pages and grab a copy to check out current functionality hands on. Please keep in mind, that this is still an alpha version – so do not use it on production data/servers! Also please note, MySQL Workbench files saved with version 5.2 cannot be opened with …

Our intrepid NorthScalers have been doing some interesting work recently in memcached land...

Last week, Dustin Sallings announced his memcached server implementation in Erlang, called EMemcached.  Besides being a cool project, there's a surprising amount of interest in the mixture of memcached and Erlang, as you can see from the comments on Dustin's announcement post.

Today, Patrick Galbraith announced that the memcached UDF's are now integrated into the Drizzle project's mainline.  Drizzle is an interesting fork of MySQL and these …

MySQL Connector/Net 6.2.0, a new version of the all-managed .NET driver for MySQL has been released. This is an alpha release and is intended to introduce you to the new features and enhancements we are planning. This release should not be used in a production environment.

It is now available in source and binary form from [http://dev.mysql.com/downloads/connector/net/6.2.html] and mirror sites (note that not all mirror sites may be up to date at this point of time - if you can't find this version on some mirror, please try again later or choose another download site.)

The new features or changes in this release are

• Connection pool cleanup timer. We now utilize a timer that cleans idle connections that are no longer connected every 3 minutes
• We are now using stream and TCP-based timeouts to handle …

There’s very few spots left for attending OpenSQL Camp 2009. I’m going, along with several other Percona employees. It’s fun stuff; you should go. I’m not really the social type so I’ll probably be sitting off to the side somewhere coding.

What a great day! I see that the drizzle team has merged in my (and Padraig O'Sullivan's) memcached Functions for Drizzle (UDFs). I'm really glad to have this in drizzle now as it adds a means of interacting with memcached from within Drizzle. I have most functions from the MySQL branch implemented now as well. I'm extremely grateful to Padraig O'Sullivan for getting this project off the ground. I was a bit stuck with the new API and C++ when I first attempted these and he designed the class setup and had the major functions working which I then picked up and added more functions as well as tests. I was also glad to have the drizzle team add in my sleep() UDF which allowed me to test expirations in these memcached functions.

These functions have some similar, but very little code from the memcached Functions for MySQL. The new UDF API is completely different than MySQL's UDF API. You have to create a class for each function that is a …

Hi ZanyWeb. Here's a pop quiz for you, and the answer may surprise you.

The MySQL manual states the following about the REPLACE statement:

REPLACE works exactly like INSERT, except that if an old row in the table has the same value as a new row for a PRIMARY KEY or a UNIQUE index, the old row is deleted before the new row is inserted.

Sounds pretty clear to me. If a row with the same primary key exists, it is deleted and then a new row is inserted.

So, given the above, if I execute the following statements in a client, what would you expect would happen behind the scenes in the storage engine?

CREATE TABLE t1 (
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY
, padding VARCHAR(200) NOT NULL
);

INSERT INTO t1 VALUES (1, "I love testing.");
INSERT INTO t1 …