high on SWiK

Installing DRBD on Hardy Part 2

Thu, 07 Aug 2008 13:13:10 -0700

The second entry which demonstrates how to setup HeartBeat on Hardy

Eat Healthy

Wed, 06 Aug 2008 21:36:11 -0700

You can dig for all the helpful tips for developing and maintaining a healthy lifestyle that not only keeps you in prime of health but also keeps you at peace of mind.

How to scale writes with master-master replication in MySQL

Wed, 06 Aug 2008 06:15:50 -0700

This post is SEO bait for people trying to scale MySQL’s write capacity by writing to both servers in master-master replication. The short answer: you can’t do it. It’s impossible.

I keep hearing this line of reasoning: “if I make a MySQL replication ‘cluster’ and move half the writes to machine A and half of them to machine B, I can increase my overall write capacity.” It’s a fallacy. All writes are repeated on both machines: the writes you do on machine A are repeated via replication on machine B, and vice versa. You don’t shield either machine from any of the load.

In addition, doing this introduces a very dangerous side effect: in case of a problem, neither machine has the authoritative data. Neither machine’s data can be trusted, but neither machine’s data can be discarded either. This is a very difficult situation to recover from. Save yourself grief, work, and money. Never write to both masters.

high availability, mysql, replication, scaling

High Performance MySQL 2nd Edition gets revised and translated

Sat, 02 Aug 2008 07:10:48 -0700

Just thought I’d update you. We got quite a few good errata from readers, and I took a couple weekends and went through the book with a fine-toothed comb, catching typos and subtle errors that crept in at some point (TPC benchmarks were labeled as TCP benchmarks — did you catch that one?). I marked up my book and mailed it to O’Reilly, who went well above and beyond what they normally do for errata. Normally, once a book is in print they will fix only serious technical errors. They fixed everything, even going as far as rearranging page breaks and moving figures to improve readability.

The second printing is on Monday August 4th. Already! I think the book has been selling a lot better than anticipated. I know I am psyched to see it remain in the top couple thousand on Amazon. And they thought it was a big deal when it broke five thousand!

In other news, it’s going to be translated into Spanish, Polish, and Portuguese. So now all my friends in Brazil will be able to read it in their native language.

And Percona’s two expert consultants in Poland, too. No undue influence was exerted. I didn’t even know it would be translated. Really! We do have a Spanish-speaking consultant who lives in Spain, but he is a native English speaker. Now, all we need are Russian, German, Lithuanian, and Ukrainian translations and I think we’ve pretty well got the company covered, at least until we hire again.

errata, mysql, OReilly, translation, writing

LCD TV VS Plasma TV

Mon, 28 Jul 2008 03:07:30 -0700

The place to get info on the latest Plasma and LCD televisions.

High school term papers are ones where ones must prove their learning abilities and competence for the lectures delivered by the instructor.

Fri, 25 Jul 2008 20:55:49 -0700

High school term papers

Fri, 25 Jul 2008 20:55:33 -0700

High school term papers are ones where ones must prove their learning abilities and competence for the lectures delivered by the instructor.

HDTV Info and Reviews

Fri, 25 Jul 2008 20:32:12 -0700

Reviews and Information for all HDTVs

Configuring Xen HA with Heartbeat for SUSE Linux Enterprise Server

Fri, 25 Jul 2008 07:01:17 -0700

Learn how to make a Heartbeat cluster with SUSE Linux Enterprise by creating a SAN for high availability storage for Xen virtual machines.

User:savingaccount

Fri, 04 Jul 2008 00:24:23 -0700

SourceForge.net: Screenshots

Tue, 22 Jul 2008 18:53:28 -0700

Stun Gun with Flashlight!

Fri, 18 Jul 2008 06:00:06 -0700

Definitely in today’s society, you might want to consider getting a Stun Gun to protect yourself. Of course, a gun can do the same job but it may kill someone while the Stun Gun doesn’t.

This Stun Gun is made of high quality ABS engineered plastic, this unit functions as a very powerful high voltage (200K) shock generator and a extremely bright flashlight in a very small and light weight package.

Very powerful and loud discharge will surely scare away any potential attacker.

via spygadgets

Brought to you by: Zedomax.com

Stun Gun with Flashlight!

Are you sure you?re reading the second edition of High Performance MySQL?

Wed, 16 Jul 2008 22:49:23 -0700

I have been getting a lot of comments and errata from people who seem to be mistakenly buying the first edition and believing it’s the second edition. A lot of the blame for this probably rests with Amazon, who did not distinguish between the two editions at all until the editor and I (among others) leaned on them persistently for about 6 weeks. I think some people are buying the second edition and getting the first edition.

I’ve even spoken to people in person who said “yeah, I’ve been reading it” and I give them a copy of the second edition to hold in their hands, and they go “whoa, that is like twice the size. I don’t have this edition at all.”

If you have any question at all, just look at the front cover. If you have the second edition, you will see it clearly in the upper right-hand corner of the cover, as shown in this picture:

I feel like a Microsoft Anti-Piracy Minion “educating” you about how to verify that you are installing Genuine Spyware. Don’t worry, the feeling will pass and I’ll be okay *grin*

If you ordered the second edition and got the first edition, Amazon should send you a new book free of charge. If they’re really making the mistake that they seem to be, I predict they’ll fix it when it starts costing them money.

No Tags

High Performance MySQL is going to press, again

Tue, 15 Jul 2008 20:48:59 -0700

Apparently High Performance MySQL, 2nd Edition is selling quite well — I’m not sure exactly how well — because we’re preparing for a second printing. This makes me very happy. I don’t think they anticipated going back to the press for quite some time.

The book fluctuates between sales rank 1000 and 2000 on Amazon during the day, and has reached as high as 600 or so. This is just phenomenal. The O’Reilly team was psyched when it broke 5000, and so was I — but now we’ve stayed under 2000 for a long time (except when Amazon sold out of it). Frankly I’d have thought that for a niche-market book like this, we’d have been in the 10,000 range or something like that.

Clearly we (the authors, editors, publisher, etc) have done something right! This is a great feeling.

Thanks for sending errata, by the way. I have just completed proofreading the whole book myself, and found a number of things that may be fixed in the second printing. I think certain types of errors won’t be fixed, but the important ones certainly will be.

Books, mysql, writing

Sphinx 0.9.8 is released!

Tue, 15 Jul 2008 18:48:54 -0700

The Sphinx project just released version 0.9.8, with many enhancements since the previous release. There’s never been a better time to try it out. It’s really cool technology.

What is Sphinx? Glad you asked. It’s fast, efficient, scalable, relevant full-text searching and a heck of a lot more. In fact, Sphinx complements MySQL for a lot of non-search queries that MySQL frankly isn’t very good at, including WHERE clauses on low-selectivity columns, ORDER BY with a LIMIT and OFFSET, and GROUP BY. A lot of you are probably running fairly simple queries with these constructs and getting really bad performance in MySQL. I see it a lot when I’m working with clients, and there’s often not much room for optimization. Sphinx can execute a subset of such queries very efficiently, due to its smart I/O algorithms and the way it uses memory. By “subset” I mean you don’t get the full complexity of SQL, but you get enough functionality for lots of the poorly-performing queries I see in the wild. It’s a 95% solution.

Is Sphinx for you? Good question. You can find answers in Appendix C in High Performance MySQL. And yes, that is why I wrote this blog post — to put in a plug for the book. *grin* But before I go, let me put in another plug for Sphinx: go vote for it on Sourceforge! If it’s voted as one of the Community Choice projects of the year, that will be fantastic.

Andrew Aksyonoff, mysql, Sphinx

Kernel-Patch für schnelleren Bus Takt beim Zugriff auf Speicherkarte im N800 - Index of /4.2008.23-mmc-kernel

Wed, 09 Jul 2008 06:08:14 -0700

Kernel-Patch für schnelleren Bus Takt beim Zugriff auf Speicherkarte im N800 - Index of /4.2008.23-mmc-kernel

Wed, 09 Jul 2008 06:07:51 -0700

High Availability Hosting with DRBD :: BobCares :: Outsourced Web Hosting Support

Tue, 08 Jul 2008 19:47:54 -0700

[from phil1eng] The High Dynamic Range (HDR) Landscape Photography Tutorial

Thu, 03 Jul 2008 11:51:17 -0700

Challenges in enterprise search

Thu, 03 Jul 2008 09:52:43 -0700

BabelVision

Thu, 03 Jul 2008 09:52:43 -0700

BibSonomy ::

Thu, 03 Jul 2008 09:52:43 -0700

CiteULike: ejrrjs's library [70 articles]

Thu, 03 Jul 2008 09:52:42 -0700

Blood Raw - "Louie"

Wed, 02 Jul 2008 22:43:53 -0700

http://youtube.com/watch?v=GOZLYkNhwpg Blood Raw “Louie” the ONLY Official HQ video.

Mozilla Labs " Blog Archive " Prism

Tue, 01 Jul 2008 20:51:58 -0700

"Prism is an application that lets users split web applications out of their browser and run them directly on their desktop." ie: run gChat or Calendar ON your desktop!

Density-Functional Theory of Atoms and Molecules

Tue, 01 Jul 2008 11:57:52 -0700

CLICK HERE >>> Price - $144.25“This book is a rigorous, unified account of the fundamental principles of the density-functional theory of the electronic structure of matter and its applications to atoms and molecules. Containing a detailed discus...

The Case for MySQL Cluster Certification

Mon, 30 Jun 2008 15:46:15 -0700

Why are the best technical books also the thinnest? To make the case, I highly recommend the MySQL 5.1 Cluster Certification Study Guide In rack units, it’s a 1U; it fits nicely into my laptop bag; and if you’re considering implementing MySQL Cluster, it can save you a world of time.

Of course, if you get the book, you should consider the certification itself. There’s a legitimate debate about the usefulness of certification exams, but the MySQL 5.1 Cluster certification is a little more important than others for a couple of reasons:

1. In case you haven’t heard it by now, Cluster isn’t always the best fit. In many cases, an active/passive failover setup is a much more flexible and cost-effective approach. It’s not always a clear-cut decision. If you’re willing to make application changes and if you understand the internal workings of MySQL Cluster, it can be an amazing solution.

To see if cluster is a good fit, I recommend the following guides:

http://www.mysql.com/why-mysql/white-papers/mysql_cluster_eval_guide.php

http://www.mysql.com/why-mysql/white-papers/mysql_ha_solutions.php

2. There aren’t many consultants and DBA’s that have actually installed and used MySQL Cluster. There’s still a lot of misconceptions. The primary misconception is: “I know MySQL, I’m sure that I can quickly set it up and support a MySQL Cluster.” Outside of MySQL professional services group, there’s limited expertise in the marketplace. If someone has a MySQL Certification, at least you know that they’re tall enough for this ride.

I thought the most important part of the book was Chapter 7 regarding Indexes in NDB tables. Unless specifically suppressed, a hash and ordered (T-tree) index will be created for primary keys. The hash index is stored in the IndexMemory pool. The ordered index is stored in the DataMemory pool.

If you want to create a unique index, that’s a bit more complicated and it takes about a page to explain. Unique indexes have performance implications, which provides even more reason that someone should really understand MySQL internals before implementing a cluster.

To summarize, I’m hesitant to say this in public, but frankly; the study guide is a good read. It won’t make the Oprah book club any time soon, but it has some good discussions about hash indexing vs. t-tree indexes, database isolation levels, ACID properties and high availability concepts.

[sidenote: I usually rip technical books in half to achieve 1U. Usually, you can safely throw the first half away.]

Teach Yourself AP Chemistry Visually in 24 Hours. The entire rapid learning course includes:. 24 Core Concept Tutorials

Mon, 30 Jun 2008 10:34:32 -0700

What if you find errors in High Performance MySQL?

Sat, 28 Jun 2008 11:01:20 -0700

The book is done now, right? What’s next?

Don’t tell my wife this, but a book is never done.

Right now I’m proofreading the printed copy. I proofread PDF after PDF during production, but some problems will always slip through and make it to paper. I’m finding quite a few little mistakes. For example, at one point we refer to TPC as TCP three times in a row. Oops.

These problems will be corrected in the next printing. Please notify me if you find any errors yourself, and I’ll add them to the list of things to fix! Also let me know if you find things that should just be “fixed” in general. For example, the layout and page-breaking on pages 364 and 365 is totally confusing — it’s hard to tell which figures are associated with which text.

I’m not offering rewards like Donald Knuth, sorry…

I will place a list of errata on the official High Performance MySQL Second Edition website, including a non-mangled Figure 8-12. (Another thing that didn’t make it through production unscathed.)

errata, printing, proofreading, writing

What it?s like to write a technical book, continued

Mon, 23 Jun 2008 14:59:36 -0700

My post on what it’s like to write a technical book was a stream-of-consciousness look at the process of writing High Performance MySQL, Second Edition. I got a lot of responses from it and learned some neat things I wouldn’t have learned if I hadn’t written the post. I also got a lot of questions, and my editor wrote a response too. I want to follow up on these things.

Was I fair, balanced and honest?

I really intended to write the post as just “here’s what it’s like, just so you’re prepared.” But at some point I got really deep into it and lost my context. That’s when I started to write about the things that didn’t go so smoothly with the publisher, and some of these things had a little extra sting in them that I would have done well to edit out.

All of us are human and the process wasn’t that bad, all things considered — the book was just a massive project that put huge demands on all of us and stressed everything from the capabilities of our chosen tools to our patience. As the editor points out in his response to my blog post, this is precisely why nobody else has ever been able to pull this off. This book stands head and shoulders above the crowd. It’s just hard to write, and very few people in the world actually have the knowledge to do it, much less the time, inclination, and ability.

Everything I said was (I believe) factual and correct, although as the editor points out there are different stories behind them. I also want to mention that I’d shared all those concerns with my editor; I avoid criticizing people behind their backs. In hindsight, throwing all of my concerns onto a blog post without warning isn’t the kind of thing I like to do either.

So I believe I was honest, but unfair to the editor. I’ve apologized to him. And by the way, yes I would work with him again, and I fully expect that it would be easier because I have learned more about the process.

I ran this post by my editor before publishing it.

A deeper explanation of my heuristics

Several people asked me to say more about my heuristics for improving the quality of the writing. I’ve already explained many of them, but here’s more:

(were|was|is|are|has been|be)( [a-zA-Z]+)? [a-zA-Z]+ed\>: This regular expression can help find some occurrences of passive voice. It finds a word or phrase that’s some variation on the verb “to be,” usually in the past tense; followed by an optional word (probably an adjective); followed by another word that ends in “-ed,” which is also potentially a verb in the past tense. This is not the only way to write in the passive voice, but it’s kind of the classic. Here are some examples: “the blog post was posted,” “the benchmark was rapidly created.”
(were|was|is|are|ha[sd] been|be)( [a-zA-Z]+)? [a-zA-Z]+e[dn]\>: An enhanced version. As I looked at the preceding point, I saw some other simple examples it doesn’t catch. For example, it doesn’t catch “had been” and it doesn’t catch verbs like “written.” Ironically, the first thing that came to mind as I thought about examples was “the book had been written.”
while|since: There’s nothing wrong with these words, except when they’re used in lieu of “because” to indicate causality. This is a problem for non-native English speakers, because these words have a temporal meaning too. For example, “Since MySQL 4.1 has no stored procedures, you have to use MySQL 5.0 if you want stored procedures.” If you aren’t a native English speaker, and even if you are, it’s easy to read that as “MySQL has had no stored procedures since version 4.1, …” and then when your eyes reach the part about MySQL 5.0, it makes no sense. My rule for this is to say “because” when I mean “because.”
using
: Real examples: “Using MyISAM tables works very well” can become “MyISAM tables work very well.” And “A final possibility is simply to switch to using a table” can become “Finally, you can use a table” instead.
in order: The phrase “in order to” can almost always be replaced by “to.” It also tends to show a rough transition between the first and second phrases in a sentence. Perhaps these phrases should be integrated into a single phrase. “You can use this regex in order to find poorly constructed sentences” can become “this regex can find poorly constructed sentences” or “You can find poorly constructed sentences with this regex.” I prefer the latter; it is very direct, and that straightforward, simple writing style is really important in complex subject matter.
of course|without saying|obviously|clearly|needless: It goes without saying, but of course these words obviously point out when I’m writing stupid things that I clearly need to take a closer look at. Needless to say, most of the phrases in this paragraph are indeed needless to say. They are a red flag for lazy writing, such as glossing over a difficult point that should instead be explained — hard work, but necessary.
whether
: I found quite a few places where the phrase “whether or not” was used. This can be shortened: “to see whether or not the disk is the problem” can become “to see whether the disk is the problem.” But better yet, the phrase often glues together poorly written phrases into an awkward sentence, just as “in order to” does. Can “whether” be replaced by “if?” Or does the sentence or paragraph just need to be reworked completely?
allow: This word can usually be replaced by “let.” “The remaining settings allow MySQL to allocate more RAM” can become “The remaining settings let MySQL allocate more RAM.” Occasionally, it is part of a larger phrase or thought needs to be shortened and clarified. “When nobody is writing, readers obtain read locks that allow other readers to do the same” became “When nobody is writing, readers can obtain read locks, which don’t conflict with other read locks.”
ensure: I found that this word is often subtly misused. It really means “guarantee” but is often used as “double-check” or “make sure.” I don’t want to be too dogmatic about this word: its usage in modern English is complex (see the usage note on assure here; that in itself might be a reason to avoid it). But I found many places where I wanted to remove it in favor of an explicit instruction that tells the reader to take action. “Ensure” as an instruction is kind of a politically correct way to tell someone to do something, and I’m not afraid to just tell you to do it if I think you need to. I don’t want you to miss my meaning.
only: I have a habit of using this word incorrectly. “I only have ten fingers” should be “I have only ten fingers.”
as (we|you)|again,: These phrases usually show a place where the writing is confused and redundant. They show up in places like “as we already said, you should tune your server” and “again, you should tune your server.” Any instruction to the reader to break the narrative flow is a place to examine whether the concepts are in the right order. Cross-references, footnotes, and reminders are not always evil, but they’re to be regarded with suspicion.

Readability metrics

The tools I used to find sentences and phrases that score badly on some readability metric were pretty helpful to me as I tightened the writing up more and more. Nobody has reviewed the book yet, but I think when they do, they’ll be unlikely to mention “oh, and by the way the writing is wonderfully compact!” If we pulled this off right, you won’t notice that the writing is clear and compact. Writing is like a stereo system: you’re supposed to hear the music, not the speakers.

Anyway, my point is that we expanded the first edition’s actual coverage many times over, and ended up with only 658 pages of actual material. So the writing is much more compressed, and to do that you have to find and eliminate confusing writing. Confusing writing usually means that the concepts don’t flow clearly, and it takes more words to say the same thing because you’re kind of bumbling about, gesturing at your meaning from several angles instead of saying it clearly just once.

Here’s how I analyzed each chapter:

I used OpenOffice’s export feature to export the file to MediaWiki format. This is a plain-text markup format. I forget now why I didn’t just export to text, but there was something about MediaWiki format that made it easier to munge with Perl.
I ran my clean_text.pl program against the exported file to convert the format to a simpler one without special characters and markup. Some of the markup (footnotes, for example) stayed in the text and confused the metrics, but that’s life.
I ran my analyze_text.pl program against this to find the “worst” places.

As I wrote in my previous post, the analyzer uses a combination of readability metrics and “other stuff” to measure the badness of each sentence and paragraph. It aggregates sentences and paragraphs by the metrics. I calculated the number of words, percent of complex words, syllables per word, number of sentences, words per sentence, and a bunch of other things, as well as the standard readability metrics. Each sentence and paragraph got scored on these. Then I printed overall metrics, and sorted the sentences and paragraphs worst-first and printed out a snippet of the offending text. Here’s a sample of chapter 3’s metrics (originally numbered chapter 4) at some intermediate stage in the writing process.

This was a lot of work. If I had been writing with Vim, I could have done better. I could have used the compiler integration and set my “make” program to the analysis program. If you use Vim and you don’t know about this, it’s a pity. My next book will be written in Vim, by the way.

Actually, I probably could have done better regardless, but this was good enough. I just searched for the snippets and then examined what was going on.

There were some false positives. For example, bullet-points often scored badly on the readability metrics, and so a five-word bullet point item would look like terrible writing just because it was short enough that it had a high percentage of complex words. It’s not an exact science. Maybe next time will be better.

If you’d like to see the source code, here’s the clean_text.pl and here’s the analyze_text.pl. Enjoy!

Perl, writing

high on SWiK

Installing DRBD on Hardy Part 2

Eat Healthy

How to scale writes with master-master replication in MySQL

High Performance MySQL 2nd Edition gets revised and translated

LCD TV VS Plasma TV

High school term papers are ones where ones must prove their learning abilities and competence for the lectures delivered by the instructor.

High school term papers

HDTV Info and Reviews

Configuring Xen HA with Heartbeat for SUSE Linux Enterprise Server

User:savingaccount

SourceForge.net: Screenshots

Stun Gun with Flashlight!

Related posts

Are you sure you?re reading the second edition of High Performance MySQL?

High Performance MySQL is going to press, again

Sphinx 0.9.8 is released!

Kernel-Patch für schnelleren Bus Takt beim Zugriff auf Speicherkarte im N800 - Index of /4.2008.23-mmc-kernel

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High Availability Hosting with DRBD :: BobCares :: Outsourced Web Hosting Support

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BibSonomy ::

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Teach Yourself AP Chemistry Visually in 24 Hours. The entire rapid learning course includes:. 24 Core Concept Tutorials

What if you find errors in High Performance MySQL?

What it?s like to write a technical book, continued

Was I fair, balanced and honest?

A deeper explanation of my heuristics

Readability metrics