A live recording of my LinuxTag 2010 presentation entitled Storage Done Right: Building a Resilient, Distributed, Highly Available Open Source iSCSI SAN is now available from our web site. If you want to find out how to build a complete SAN from 100% open source, do take a look!

I do apologize for the less-than-optimal sound quality. I did the recording myself with my laptop mike, so unfortunately there’s quite a bit of clipping in the audio track. I hope my ramblings are still somewhat audible.

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While Yves presents a valid approach for managing NDB with Pacemaker and the anything Linux-HA resource agent (a generic wrapper for any daemon based application), the XML configuration shown is likely to have people running away screaming. This is how we had to do things back in the Heartbeat 2 days, which meant that as a cluster admin you would permanently run around with a loaded cocked shotgun with the muzzle pressed firmly against your foot.

Those days are long gone. Please don’t do this anymore. You also no longer need to use the low-level tools such as cibadmin or crm_attribute.

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This post covers the basic information of files that MySQL Server uses / creates for various tasks. my.cnf : It is the main configuration file for MySQL. You may find it under base directory in windows or under /etc/. .sock : mysqld creates a socket for programs to connect to and notes in this file. It is named [...] Related posts:

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In mysql we have — , /* and /*! comments.  This post is mainly about very basic c-style comments. /*! : C-Style comments in MySQL We normally see comments in MySQLdump as follows: /*!40000 ALTER TABLE `a` DISABLE KEYS */; Or /*!50013 DEFINER=`root`@`localhost` SQL SECURITY DEFINER */ These are actually C-Style comments which has embeded sql and treated specially [...] Related posts:

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Assume we’ve a table with 100 rows and we need to select all columns but one. The problem is headache of actually typing out all 99 required columns!! Solutions / Ideas to above problem are: Ignorance is bliss. Select all(*) and ignore the column. Manually type column names or manage it with copy paste! Create a view from original table [...] Related posts:

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There are set of commands that MySQL itself interprets. You may use “help” or “\h” at the mysql> prompt to list them. Below are the 5 most useful MySQL Command Options. 1. \# OR rehash: Enable automatic rehashing. Do you have long table names, you find it difficult to remember tablenames or you’re just as lazy as I [...] Related posts:

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A lot of articles have been written on splitting mysqldump and grab required tables. Long back when Shlomi had suggested a “sed” way, I actually shell scripted it, and now publishing. This shell script will be grabbing the tables you want and pass it to tablename.sql. It’s capable to understand regular expressions as I’ve added sed -r option. Also [...] Related posts:

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Here is one more procedure – (this time) for mass renaming of table. Adding and Removing table-name prefixes A friend of mine was renaming 100+ tables by using replace methods in notepad. I showed em a bit better editor: Editplus and then I thought of rescue rest of those who are still interested in some [...] Related posts:

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Loading csv or delimited data files to MySQL database is a very common task frequently questioned about and almost everytime LOAD DATA INFILE come into rescue. Here we will try to understand some of the very common scenarios for loading data into MySQL Database. The Load Data Syntax: LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE ‘file_name’ [REPLACE | IGNORE] INTO [...] Related posts:

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I’m having RHEL 5 (32-bit) and MySQL-5. I was trying to check how much is the Memory Utilization limits for MySQL 5 on 32bit OS. We can easily calculate the maximum capacity of the address space is 2^32 bytes and that is where these limits come from. * For MYSQL 5.0: Following are memory (storage) limits: Max DB size: [...] Related posts:

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Recently MySQL has offered MySQL Certification Free Retake on both DBA or Developer Certifications for a limited time. For MySQL Certifications: 1. MySQL 5.0 Data Base Administrator Certification (SCMDBA) - MySQL 5.0 DBA Part I Certification (CX-310-810) - MySQL 5.0 DBA Part II Certification (CX-310-811) 2. MySQL 5.0 Developer Certification (SCMDEV) - MySQL 5.0 Developer Part I Certification (CX-310-812) - MySQL 5.0 [...] Related posts:

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We all are aware about the acquisition happened to MySQL; Sun and now Oracle. A common understanding tells me that a business will always seek profit; so will Oracle. And thats where worries and fear for existance of MySQL as an open-source and future growth are. Here is what Micheal “Monty” Widenius shares with all of us: We all [...] Related posts:

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This procedure lists available database objects under passed database name. It lists present Tables, Views, Stored Procedures, Functions and Triggers under particular database. It also lists storage engine of tables. It uses information schema database to gather information and storing in a temporary table. Usage: call xplore(database-name); - Procedure will search through information schema for database objects under database-name. Download Stored [...] Related posts:

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This procedure will split  a “;” separated column in to new fields preserving ids. This is very specific problem, lets check it with example. Consider a sample table test: And we want output as follows: So again I wrote a procedure. Procedure will read a data from “tmp” table and will split data by my_delimiter delimiter and generate a temporary [...] Related posts:

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Well procedures mainly carried out working with information schema and it’s usage in stored procedure. Procedures are fairly simple and easy to understand. 1. Edit_table – following procedure executes queries to particular table if it exists. Basically I created it to satisfy a need of altering a table if column exists. Now it can be used to execute any [...] Related posts:

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For monitoring replication we know a lot of tools and codes – but this one is different because I wrote it Well this is fairly simple php code for monitoring a master master replication setup. It requires a single shared login id available on both MySQL servers. It will display in tabular format following details: File: Present binary [...] Related posts:

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While going through mysql doc and MySQL Server Memory Usage, I noted following quick points regarding how mysql uses memory. We have global buffers which are allocated irrespective of connections as and when mysql server is started. Along with that mysql server allocates memory to each thread to perform respective tasks. So the formula goes: Mysql Server Memory Usage [...] Related posts:

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Creating scheduled backup using administrator is an easy task. Follow the GUI and you’re done. But I observed something different! MySQL Version: 5.0.83 Community MySQL Administrator: 1.2.17 Machine: Intel P4, Windows XP, Enough RAM Logs: General, Error & irrelevant here though Slow query. Prologue: Administrator performs scheduled backup properly in normal scenario. What I was watching: Administrator’s Auto-Backup behaviour with [...] Related posts:

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Monitoring a replication is an important aspect. As replication includes multiple nodes, it is essential to track activity and status across all mysql servers involved in replication. To monitor replication we know commands like: Show slave status; Show master status; Refer: http://dev.mysql.com/doc/refman/5.0/en/sql-syntax-replication.html But when it comes to non-gui interface, it becomes little tedious. With some efforts, I managed to make a [...] Related posts:

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This article is a brief step-by-step tutorial on the subject task which is divided into the following main parts: Installing two MySQL Server Instances Setting up master-slave replication Setting up slave-master replication Let’s begin covering those points… Installing Two MySQL Server Instances on Windows: 1. Install MySQL: Download MySQL Binaries from dev.mysql.com. Install normal MSI Package of mysql. (I used: mysql-essential-5.0.83-win32). * Following MSI [...] Related posts:

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“Show Slave Status” command has a last column “Seconds_Behind_Master”, which gives us idea about how much time slave is lagging behind master. It is an important to be considered parameter in monitoring and maintaining replication. This article explains us a way to monitor replication slave lag time. It also includes a sample batch scripts to automate [...] Related posts:

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What will you do if one day some one ask you to find single string in all databases, alltables and in all columns? I just read such question and tried to find a “ready made” solution. Reusability is Key Concept !! But I ended up finding no “copy-paste” material. Some of the posts like http://vyaskn.tripod.com/search_all_columns_in_all_tables.htm helped me out and supported my [...] Related posts:

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Consider we’ve already set a master-master replication. Now create following table on Server1: CREATE TABLE `temp` ( `id` int(10) NOT NULL auto_increment, PRIMARY KEY (`id`) ) ENGINE=MyISAM AUTO_INCREMENT=12 DEFAULT CHARSET=latin1; The table will will get replicated on Mysql Server2 in the master-master setup. Now insert value on Mysql Server1 as follows: mysql>insert into temp values(null); On Mysql Server2 in replication you will see [...] Related posts:

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One of the things that repeatedly seem to puzzle users about the DRBD is the question of whether to use internal or external metadata. Remember, DRBD sets aside a small area on a local disk (on every cluster node) where it keeps the Activity Log, the quick-sync bitmap, data generation UUIDs, and a few other bits and pieces for local housekeeping.

The specific aspect that is to be discussed here is the Activity Log. Without going into too much detail, let’s be satisfied with the factoid that DRBD

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As someone may have noticed, I recently wrote a trilogy on how to dive into the MySQL Cluster source code. Unfortunately my overtures towards the MySQL Cluster source code ended up being only a look-but-don't-touch affair, as I failed to actually get to touch her internals with my text editor. Even so, in this post I'd like to tell about the background to my love affair with this beauty, by relating to some benchmarks I've been working on together with my customers.

Oh, and I'd like to apologize already, that I cannot mention where these benchmarks were done, what the schema looked like and the exact numbers. If you want that kind of real benchmarks, you should read Mikael's blog, or watch the slides from this webinar

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(Continued from part II where I tried to fix a bug and found out that the affected part of the code had been rewritten, so the bug didn't exist anymore.)

Magnus gives a helpful hint...

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This is part II of my efforts to prove myself that I can do programming. In part one I successfully created a MySQL Cluster branch for myself and compiled it.

Let's go to the public MySQL bug database and see if there are any trivial MySQL Cluster bugs I could sharpen my teeth on. Heh, sure enough #32658 looks simple enough. There is a typo in an output string - so I could fix that without even doing any C++ code! (Funnily, a MySQL internal comment to the bug says something about it being embarrassing. Guess it is a good bug for me then, as patching over embarrasments is what Sales Engineers do routinely :-)

Let me see...

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My collagues Anders and even Ivan sometimes blog about the grandeur of being a Sales Engineer. And I agree, it is a great job, probably the best I ever had, so far. But let me share a secret: It's not as technical as you'd think. Sure, they call me a "pre-sales consultant" alright, but I would be ashamed of comparing my own work with those of the real consultants. I sometimes jokingly say that the most amazing technical things in my job are airplanes (they fly in the air!) and how to make a nice slideshow. (OpenOffice Impress sucks btw, and I always envy my OS X + Keynote using friends on this one

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By popular demand, we are now offering an on-line incarnation of our DRBD Total training sessions, normally taught in a 4-day on-site course. The next such training commences on May 18 (next Monday), and we still have a few seats left — so if you’re interested, grab one while you still can!

What’s covered in this course?

Here is an overview of the course highlights:

• Introduction to High Availability Clustering & DRBD
• Setting up a DRBD resource and common failure scenarios
• Configuring and running the Heartbeat/Pacemaker cluster stack
• Highly available NFS, MySQL, and virtualization
• DRBD performance tuning and optimization
• DRBD integration with Red Hat Cluster Suite
• Recent and future DRBD development

Every course attendee gets a virtual

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Upload Image to MySQL using PHP As a new-bie to php/mysql, I tried different stuffs. So here I’m with my php code for Image Upload to MySQL. Its a quite simple code with two php files one to display and one to upload. For Image Upload code, I’ve added code download link upload-image-mysql-demo.zip at the end of [...] Related posts:

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