The latest from the MySQL community

There was a discussion on LinkedIn one month ago that caught my eye:

Database search by "within x number of miles" radius?

Anyone out there created a zipcode database and created a "search within x numer of miles" function ?
Thankful for any tips you can throw my way..

J

A few people commented that some solutions wouldn't scale. To understand why these sorts of geographic search queries are problematic in MySQL, it's best to show some execution plans on dummy data:

PLAIN TEXT SQL:

1. EXPLAIN …

I recently had the chance to witness the effects of innodb_adaptive_flushing on the performance of InnoDB Plugin 1.0.5 in the wild, which Yasufumi wrote about previously here and here.

The server in question was Solaris 10 with 8 disk RAID10 and 2 32GB SSDs used for ZIL and L2ARC, 72G RAM and 40G buffer pool. We started it up with innodb_adaptive_flushing=OFF and innodb_doublewrite=OFF, then ramped up traffic and everything looked stable ... but I noticed one troubling thing: ~2GB of uncheckpointed data.

mysql> SHOW INNODB STATUS\G
....
Database pages      2318457
Old database pages  855816
Modified db pages   457902
Log flushed up to   10026890404067
Last checkpoint at  10024612103454
....

We enabled …

Every time I need to install or reconfigure a new workstation, I review the set of tools I use. It's an opportunity to refresh the list, reconsider the usefulness of old tools and review new ones. During my first week at Open Market I got one of these opportunities. Here is my short list of free (as in 'beer') OSS tools and why they have a place in my tool chest.
Testing Environments
Virtual Box
Of all the Virtual Machines out there, I consider Virtual Box to be the easiest to use. Since I first looking into it while I was still working at Sun/MySQL, this package has been improved constantly. It's a must have to stage High Availability scenarios or run tools that are not available in your OS of choice.
MySQL SandboxDid you compile MySQL from source and want to test it without affecting your current …

There are a few parameters that may be worth looking at when first installing InfiniDB; NumBlocksPct for managing memory, PmMaxMemorySmallSide for optimizing join behaviors, and MaxOutstandingRequests which changes how individual queries share resources.

The NumBlocksPct parameter manages the amount of memory on each server allocated to store data blocks and is expressed as a % of server memory. For example, to allocate 5 GB for the data buffer cache for a server with 8GB memory, set thRead More...

There are a few parameters that may be worth looking at when first installing InfiniDB; NumBlocksPct for managing memory, PmMaxMemorySmallSide for optimizing join behaviors, and MaxOutstandingRequests which changes how individual queries share resources.

The NumBlocksPct parameter manages the amount of memory on each server allocated to store data blocks and is expressed as a % of server memory. For example, to allocate 5 GB for the data buffer cache for a server with 8GB memory, set thRead More...

This is part 3 of our series.  In part 1 we talked about boosting performance with memcached on top of MySQL, in Part 2 we talked about running 100% outside the data with memcached, and now in Part 3 we are going to look at a possible solution to free you from the database.  The solution I am going to discuss here is Tokyo Cabinet and Tyrant.

I am not going to give you a primer  or Tutorial on Tyrant and Cabinet, there are plenty of these out there already.  Instead I want to see what sort of performance we can see compared to MySQL and Memcached, and later on other NoSQL solutions.  Tokyo actually allows you to use several types of databases that are supported, there are hash databases which …

For the my previous post, there was comment to suggest to test db_STRESS benchmark on XtraDB by Dimitri. And I tested and tuned for the benchmark. I will show you the tunings. It should be also tuning procedure for general heavy writing workloads.

At first, <tuning peak performance>. The next, <tuning purge operation> to stabilize performance  and to avoid decreasing performance.

<test condition>

Server:
PowerEdge R900, Four Quad Core E7320 Xeon, 2.13GHz, 32GB Memory, 16X2GB, 667MHz

db_STRESS:
32 sessions, RW=1, dbsize = 1000000, no thinktime

XtraDB: (mysql-5.1.39 + XtraDB-1.0.4-current)
innodb_io_capacity = 4000
innodb_support_xa = false
innodb_file_per_table = …

Since I started doing the occasional consulting job for Open Query, I've seen a lot of MySQL servers that have been installed once and then forgotten about. This gave me the idea to do a short presentation about some basic MySQL server configuration. The first go was at DrupalCampMelbourne and I recently tried (and failed) to cram it into a three minute lightning talk slot at the LUV September meeting.

The title of the talk is (now) MySQL > YourSQL. I chose this not because I think that MySQL is better than the $other_database you use or because I may or may not run a newer version of MySQL on better hardware, but because I use InnoDB and …

As you may know, InnoDB has 2 limits for unflushed modified blocks in the buffer pool. The one is from physical size of the buffer pool. And the another one is oldness of the block which is from the capacity of transaction log files.

In the case of heavy updating workload, the modified ages of the many blocks are clustered. And to reduce the maximum of the modified ages InnoDB needs to flush many of the blocks in a short time, if these are not flushed at all. Then the flushing storm affect the performance seriously.

We suggested the "adaptive_checkpoint" option of constant flushing to avoid such a flushing storm. And finally, the newest InnoDB Plugin 1.0.4 has the new similar option "adaptive_flushing" as native.

Let's check the adaptive flushing options at this post.

HOW THEY WORK

< adaptive_checkpoint=reflex (older method)>

Just in case you missed the live event, we have a recording of the ZFS + SSD for databases webcast

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You can also download the slides from Slide share. Download Slides