Pythian Group

Persistence Smoothie: Blending NoSQL and SQL – see user feedback and comments at http://joind.in/talk/view/1332.

Michael Bleigh from Intridea, high-end Ruby and Ruby on Rails consultants, build apps from start to finish, making it scalable. He’s written a lot of stuff, available at http://github.com/intridea. @mbleigh on twitter

NoSQL is a new way to think about persistence. Most NoSQL systems are not ACID compliant (Atomicity, Consistency, Isolation, Durability).

Generally, most NoSQL systems have:
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Most of this stuff is not PHP specific, and Python or Ruby or Java or .NET developers can use the tools in this talk.

The session on joind.in, with user comments/feedback, is at http://joind.in/talk/view/1320.

Slides are at http://talks.php.net/show/confoo10

“My name is Rasmus, I’ve been around for a long time. I’ve been doing this web stuff since 1992/1993.”

“Generally performance is not a PHP problem.” Webservers not config’d, no expire headers on images, no favicon.

Tools: Firefox/Firebug extension called YSlow (developed by yahoo) gives you a grade on your site.
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Is it Friday already? Where does the time go? Lots of stuff going on this week–here’s a few of the things that I found interesting.

Operating Systems

Russia Today-TV announced the existence of “Red Star”, the new OS developed in North Korea and based on Linux. I found this by way of Slashdot of course, citing the source as The Korea herald. According to the article it looks very much like the Windows UI, and features a “My Country” icon that allows connection to Korea’s closed internet-like network and the Woori office application. Slightly more information can be found there in the article N. Korea develops own OS.

The upcoming Ubuntu 10.04 (Lucid Lynx) has had the third alpha version released. Read the rest of this entry . . .

Baron makes an excellent point in Why you should ignore MySQL’s key cache hit ratio — ratio is not the same as rate. Furthermore, rate is [often] the important thing to look at.

This is something that, at Pythian, we internalized a long time ago when thinking about MySQL tuning. In fact, mysqltuner 2.0 takes this into account, and the default configuration includes looking at both ratios and rates.

If I told you that your database had a ratio of temporary tables written to disk of 20%, you might think “aha, my database is slow because of a lot of file I/O caused by writing temporary tables to disk!”. However, that 20% ratio may actually mean a rate of 2 per hour — which is most likely not causing excessive I/O.

To get a sense of this concept, and also how mysqltuner works, I will show the lines from the mysqltuner default configuration that deal with temporary tables written to disk. Read the rest of this entry . . .

I recently granted ALTER access in MySQL so a user could run the ALTER TABLE command . However after I granted the necessary privileges, the user was still not able to perform the tasks needed. Reproducing the issue using a test instance, I granted a test user the required privileges and MySQL reported no errors or warnings when the ALTER TABLE was run:
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Good afternoon and welcome to another edition of the usually, mostly, kind of weekly news for System Administrators. I was on a much needed holiday for the last couple of weeks. Many thanks to Tim for filling in on the last one. What with clients’ priorities and February being a short month, we did not have the cycles to get a blog out last week, and this one will be short because, frankly, the IT news world has been a bit slow of late. With that I shall cease my preface and move on to . . . 

Operating Systems

The Phoronix media site is reporting that the end may be near for Open Solaris since the purchase of Sun by Oracle. Oracle has been quiet on its plans for the free/open source version of its Solaris operating system, and the Service Life Status for OpenSolaris Operating System Releases does show the GA (General Availability) phase support as “TBD“. See a little more info in Oracle Still To Make OpenSolaris Changes. This one will be worth watching and I’ll update the blog when more is available. Read the rest of this entry . . .

Applying binary logs to a MySQL instance is not particularly difficult, using the mysqlbinlog command line utility:

$> mysqlbinlog mysql-bin.000003 > 03.sql
$> mysql < 03.sql

Turning off binary logging for a session is not difficult, from the MySQL commandline, if you authenticate as a user with the SUPER privilege:

mysql> SET SESSION sql_log_bin=0;

However, sometimes you want to apply binary logs to a MySQL instance, without having those changes applied to the binary logs themselves. One option is to restart the server binary logging disabled, and after the load is finished, restart the server with binary logging re-enabled. This is not always possible nor desirable, so there’s a better way, that works in at least versions 4.1 and up:
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Just the facts:
What: MySQL user community dinner
Who: me, you, and many MySQL community members
When: Monday, April 12th – Meet at 6:30 at the Hyatt Santa Clara or at 7 pm at the restaurant
Where: Pedro’s Restaurant and Cantina – 3935 Freedom Circle, Santa Clara, CA 95054
How: Comment on this blog post to add your name to the list of probable attendees

I was sad that last year there was no community dinner, and I missed the one the year before when Jonathan Schwartz and Rich Green made an appearance. This year I am determined not to miss it, and so I am calling for a community (pay-your-own-way) dinner on Monday, April 12th, at Pedro’s – a Mexican restaurant that has vegetarian and vegan options. I think Monday is a better time because many folks arrive Sunday evening, or even Monday morning (there are tutorials on Monday, but not everyone attends).
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Good morning and welcome to a new Blogrotate. We missed last week’s edition because last week was insanely busy. We take customer service very seriously here at Pythian, so when there is a conflict between client issue and a blog, the client always wins out. ‘Nuff said.

It’s been another busy week here and shows no sign of slowing, but here’s a few of the things we found interesting this week.

Operating Systems

The H Online is reporting that Linus Torvalds named one of the 100 most influential inventors by “The Britannica Guide to the World’s Most Influential People”. More info can be found there, as well as a link to some free sample pages from the book. Of course, Bill Gates was also on the list.

Could it be that Microsoft ranks third in Linux sales? Read the rest of this entry . . .

Last month at the Boston MySQL User Group, I went through the meanings of INNER, LEFT/RIGHT OUTER, CROSS, NATURAL joins, how to do a FULL OUTER JOIN in MySQL, and what STRAIGHT_JOIN means. I also explained how to recognize when you want those types of joins, and best practices for the semantics of writing joins and design patterns. Subqueries were explained in this session, and some examples of how to think differently so that you end up writing JOINs instead of subqueries. The slides (slightly different from the slides in the video — due to error correction) can be found at http://technocation.org/files/doc/2010_01MySQLJoins.pdf.

Here’s the video:
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