ClusterJ Architecture

MySQL have been working on a new way of accessing MySQL Cluster using Java. Designed for Java developers, the MySQL Cluster Connector for Java implements an easy-to-use and high performance native Java interface and OpenJPA plug-in that maps Java classes to tables stored in the high availability, real-time MySQL Cluster database.

There is a series of 2 webinars coming up, as always these are free to attend – you just need to register in advance:

Part 1: Tuesday, February 16, 2010: 10:00 Pacific time

• an overview of the MySQL Cluster Connector for Java
• what these technologies bring to Java developers
• implementation details of the MySQL Cluster Java API and Plug-In for OpenJPA
• configuring the connection to …

I happened upon this old LinuxJournal article about how the University of Zululand in South Africa used MySQL and other Free Software to make do with a 128 kbit (and later 768 kbit) internet connection for their staff and students.

This made me remember the trip I made to another African country, Burkina Faso, 15 years ago:

With the huge amount of work and numerous difficult obstacles facing my work on the MariaDB project, it can be …

Motives and the Features

For the servers running in our new network, I was in need for a highly configurable, but easy-to-use backup solution that can take online backups of VMs and MySQL databases running multiple storage engines.

Since my colleagues are all researchers or programmers but there are no dedicated engineers for managing our system, I decided to write a set of command line scripts to accomplish the task instead of using an existing, highly-configurable but time-taking-to-learn backup solutions, like Amanda.

And what I have come up with now is a backup solution with following characteristics, let me introduce them.

• a central backup server able to take backup of other servers over SSH using public-key authentication
• no need to install backup agents into each server
• LVM snapshot-based online, …

According to different sources from the web the decision about the Oracle - Sun merger has been approved by the European commission soon. So at least in the West it is clear what is going on. Let us see what the East decides... [1], [2].

Oracles arch-enemy Microsoft has already brought its weapons in position against the target with its: "Microsoft offers Oracle-phobes MySQL migration tool" [3], [4]. So far so good. Nothing new, nothing special.

What made me a bit edgy was the following Oracle blog series about their Oracle Warehouse Builder (OWB):

• OWB 11gR2 – MySQL Open Connectivity [5]
• OWB 11gR2 – MySQL Bulk Extract [6]

OWB seems to be a great tool to move data around from different sources, to mix them and to extract some useful results.

It looks like with the new 11gR2 release there "... were significant changes to mapping to support native …

According to different sources from the web the decision about the Oracle - Sun merger has been approved by the European commission soon. So at least in the West it is clear what is going on. Let us see what the East decides... [1], [2].

Oracles arch-enemy Microsoft has already brought its weapons in position against the target with its: "Microsoft offers Oracle-phobes MySQL migration tool" [3], [4]. So far so good. Nothing new, nothing special.

What made me a bit edgy was the following Oracle blog series about their Oracle Warehouse Builder (OWB):

• OWB 11gR2 – MySQL Open Connectivity [5]
• OWB 11gR2 – MySQL Bulk Extract [6]

OWB seems to be a great tool to move data around from different sources, to mix them and to extract some useful results.

It looks like with the new 11gR2 release there "... were significant changes to mapping to support native heterogeneous connectivity …

I’ve posted a new table statistics patch which is the next version of the session table/index statistics patch This version of the patch adds slow query log output. If a query is logged to the slow query log it will have row count statistics added to it.

I’m not sure about the format of the log which is why I’m posting this so early. The first format I tried was:

# Time: 100119 19:24:37
# User@Host: [ebergen] @ localhost []
# Query_time: 10 Lock_time: 0 Rows_sent: 7 Rows_examined: 3
# Rows_read: sbtest.foo:3, sbtest.bar:3,
select * from foo a, bar b where sleep(1) = 0;

Discount educational software

Where there …

Some background is needed. Crosstabs (also called data cubes or pivot tables, have been one of my favorite hacks for long time. In 2001 I wrote an article about a simple …

At dealnews we have three tiers of servers. First is our development servers, then staging and finally production. The complexity of the environment increases at each level. On a development server, everything runs on the localhost: mysql, memcached, etc. At the staging level, there is a dedicated MySQL server. In production, it gets quite wild with redundant services and two data centers.

One of the challenges of this is where and how to store the connection information for all these services. We have done several things in the past. The most common thing is to store this information in a PHP file. It may be per server or there could be one big file like:

<?php

if(DEV){
    $server = "localhost";
} else {
    $server = "10.1.1.25";
}

?>

This gets messy quickly. Option two is to …

I ran into an issue where curl request run within few ms from command line but same url fetch was taking over 10 secs. After doing some debugging and research it turned out that call to check (getaddr ipv6 was timing out. Obviously you can do multiple things to fix this (including enabling ipv6 support) but since I did not have a need for ipv6 (it is disabled in my network configuration), I decided to recompile curl and disable ipv6. Here is the command for recompiling curl and installing into /usr/local/curl directory with ipv6 disabled.

./configure –prefix=/usr/local/curl –disable-ipv6

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DISCLAIMER: Please be smart and use code found on internet carefully. Make backups often. And yeah.. last but not least.. I am not responsible for any damage caused by this posting. Use at your own risk.

An article of mine, "Data in Flight," is published in this month's Communications of the ACM. In it, I took the time to explain, in layman's terms, why I think streaming database technology is a game-changer.

Many pundits have latched on to the term CEP (Complex Event Processing) to describe this technology. CEP is a legitimate and important application, and I believe that streaming SQL is a good way to solve it, but the article tries to put a bit of space between the two concepts. There are so many problems that benefit from the declarative, relational approach but where the data arrives incrementally and the problem can be solved much more efficiently by a streaming engine working (mainly) in memory than …