One of the main goals in architecting a Disaster Recovery (DR) solution is to make a DR failover transparent to the end users. Too often, users must reboot their desktops, clear their browser cache and the jinitiator jar cache, and so on, even when we have made sure that the post-failover URL of the 11i instance is the same. After a failover of an 11i instance from a primary site to a DR site, if the user can operate without changing anything in his desktop, only then can we say that the goal is achieved.
The MySQL Community version is different in theory from the Enterprise version in relation to the following points….
Recently, I had an opportunity to tune latch contention for cache buffers chain (CBC) latches. The problem was high CPU-usage combined with poor application performance. A quick review of the statspack report for 15 minutes showed a latch-free wait as the top event, consuming approximately 3600 seconds in an 8-CPU server. CPU usage was quite high. First, I’ll find the SQL suffering from latch contention and objects associated with the access plan for that SQL. Next,I will find the buffers involved in latch contention, and map that back to objects. Finally, I will match these two techniques to pinpoint the root cause.
In this article, I will be looking at are online tools*, rather than the other (very useful) tools that are offline–such as myisamchk or setting innodb_force_recovery and starting up the server–both of which can sometimes save our skins. I’ll cover offline methods in another post, as they are outside of the scope for this post.
Welcome to the 107th edition of the Log Buffer. My name is Keith Murphy and I am a MySQL database administrator for the Pythian Group. In addition, I am the editor of MySQL Magazine. This is my second go for the Log Buffer, so I must be doing something right!
Exceptional Software Explained: Embrace Error, by Robert “r0ml” Lefkowitz of Asurion. One of the contenders for “best open source comedian”, r0ml delivers a humorous look at the past and future of software development models. This keynote was delivered at OSCon 2008 on Tuesday evening.
Brian Aker gives the “zinger” lightning talk about the newly announced “Drizzle”. This short (under 8 minutes) video captures Aker’s highlights of why he started the Drizzle project and how Drizzle is different from MySQL — both in what has been removed from MySQL and what features Drizzle can accomodate.
While PBXT is transactional, it writes only once, to a log. You can think of this log as the database table, as PBXT doesn’t keep table data in the tradition sense. This can seem very strange to someone used to working with MyISAM table files or InnoDB tablespace files, but it offers a number of benefits…
With some of the new functionality that was introduced in DBD::Oracle 1.21, you can no longer use the Oracle 7 and most early 8 clients to build DBD::Oracle. I hope this little table will help you choose which version of DBD::Oracle is right for you. As there are dozens and dozens of different versions of Oracle’s clients, I did not bother to list any of them, just the major release versions of Oracle that are out there.
The slides for the talk are downloadable here and there is also a link to the video.