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MySQL Feed

Oracle MySQL resources, news, and support articles.

Infinite Replication Loop

Last week I helped 2 different customers with infinite replication loops. I decided to write a blog post about these infinite loop of binary log statements in MySQL Replication. To explain what they are, how to identify them… and how to fix them.

An infinite replication loop is one or more transactions that are replicating over and over in a Multi Master Replication relationship. This happens because those transactions belong to a server-id which is different from the two actual masters.

Let’ s have a look first at the normal flow:

Multiple MySQL instances on Fusion-io ioDrive

It is known that MySQL due internal limitations is not able to utilize
all CPU and IO resources available on modern hardware.
Idea is to run multiple instances of MySQL to gain better performance on Fusion-io ioDrive card.

Full report is available in PDF

For tests we used tpcc-mysql package, which generates TPCC-like workload on MySQL systems.

Keep your MySQL backend online no matter what + TGIF Contest!

On Oct. 25th I will be presenting my conference session “Keep your MySQL backend online no matter what” at the Percona Live London Conference. Considering their is a variety of highly knowledgeable MySQL experts speaking at this event I wanted to give my talk a special plug so you won’t miss THIS knowledgeable MySQL expert speak! ;)

$1000 per hour Servers, Anyone?

Amazon's spot market for computing power is set up as an open market for surplus servers. The price is dynamic and depends on demand. So when demand is low, you can get computing instances for rock bottom prices. When you do that you normally set a range of prices you're willing to pay. If it goes over your top end, your instances get killed and re-provisioned for someone else.

Fighting Spam: Word Verification

Hi All,

this is a quick note to let you know that from now on, commenters on this blog will need to complete a word verification (captcha) step.

Personally, I regret to have to take this measure. Let me explain why I'm doing it anyway.

Since 3 months or so, moderating comments on this blog is becoming a real drag due to a surge in anonymous spam. While bloggers spam detection is quite good, I still get notificaton mails prompting me to moderate. I feel this is consuming more of my time than it's worth.

When Does InnoDB Update Table Statistics? (And When It Can Bite)

An InnoDB table statistics is used for JOIN optimizations and helping the MySQL optimizer choose the appropriate index for a query. If a table’s statistics or index cardinality becomes outdated, you might see queries which previously performed well suddenly show up on slow query log until InnoDB again updates the statistics. But when does InnoDB perform the updates aside from the first opening of the table or manually running ANALYZE TABLE on it? The 2 instances below are documented from the MySQL and InnoDB plugin’s manual:

When systems scale better than linearly

I’ve been seeing a few occasions where Neil J. Gunther’s Universal Scalability Law doesn’t seem to model all of the important factors in a system as it scales. Models are only models, and they’re not the whole truth, so they never match reality perfectly.

Fundamental performance and scalability instrumentation

This post is a followup to some promises I made at Postgres Open.

Instrumentation can be a lot of work to add to a server, and it can add overhead to the server too. The bits of instrumentation I’ll advocate in this post are few and trivial, but disproportionately powerful.

If all server software shipped with these metrics as the basic starting point, it would change the world forever:

Surge 2011 slides, recap

This year’s Surge conference was a great sophomore event to follow up last year’s inaugural conference. A lot of very smart people were there, and the hallway track was great.

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