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Getting started with Tungsten Replicator and Tungsten Sandbox
We have been busy, at Continuent. In addition to our usual work with high performance replication, we have addressed usability issues, since we know that a hard-to-use problem, no matter how powerful, has low adoption. Thus, is with some personal satisfaction that I can announce the release of Tungsten Replicator 2.0.3, which comes with several huge improvements in matter of user friendliness. The new installation procedure is so user friendly, in fact, that I was able to build a sophisticated tungsten-sandbox with a 150-line shell script. (The corresponding features …
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A review of MySQL Replication by Russell Dyer

MySQL Replication by Russell Dyer, Silent Killdeer, 2010. About 180 pages.

This is a pocket-sized guide to setting up and managing MySQL replication. It is self-published and made via print-on-demand technology. Topics include how replication works, setting up replication, making backups, and administering replication after it’s working. There are several appendixes for replication-related functionality in the MySQL server and command-line tools.

This book doesn’t go into great depth, so don’t expect it to be a reference manual to replication internals or anything like that. It’s more of a how-to manual for beginners, walking through the basics of binary and relay logs, SQL and I/O …

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Aligning IO on a hard disk RAID – the Benchmarks

In the first part of this article I have showed how I align IO, now I want to share results of the benchmark that I have been running to see how much benefit can we get from a proper IO alignment on a 4-disk RAID1+0 with 64k stripe element. I haven’t been running any benchmarks in a while so be careful with my results and forgiving to my mistakes

The environment

Here is the summary of the system I have been running this on (for brevity I have removed some irrelevant information):

# Aspersa System Summary Report ##############################
    Platform | Linux
     Release | Ubuntu 10.04.2 LTS (lucid)
      Kernel | 2.6.32-31-server
Architecture | CPU = 64-bit, OS = 64-bit
# Processor …
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Aligning IO on a hard disk RAID – the Theory

Now that flash storage is becoming more popular, IO alignment question keeps popping up more often than it used to when all we had were rotating hard disk drives. I think the reason is very simple – when systems only had one bearing hard disk drive (HDD) as in RAID1 or one disk drive at all, you couldn’t really have misaligned IO because HDDs operate in 512-byte sectors and that’s also the smallest amount of disk IO that systems can do. NAND flash on the other hand can have a page size of 512-bytes, 2kbytes or 4kbytes (and often you don’t know what size it is really) so the IO alignment question becomes more relevant.

It was and still is, however, relevant with HDD RAID storage – technology we have been using for many years – when there’s striping like in RAID0, 5, 6 or any variation of them (5+0, 1+0, 1+0+0 etc.). While IO inside the RAID is perfectly aligned to disk sectors (again due to the fact operations are done in …

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MySQL Error 1025 (HY000) : Error on rename

When we try to modify any column which is having foreign key reference with any other table in InnoDB storage engine you will get Error 1025 :  Error on rename For example : Create two table in InnoDB storage engine CREATE TABLE CountryParent  ( Code CHAR(3) NOT NULL, Name CHAR(52) NOT NULL, PRIMARY KEY (Code)  [...]

A review of MySQL Replication by Russell Dyer

MySQL Replication by Russell Dyer, Silent Killdeer, 2010. About 180 pages. This is a pocket-sized guide to setting up and managing MySQL replication. It is self-published and made via print-on-demand technology. Topics include how replication works, setting up replication, making backups, and administering replication after it’s working. There are several appendixes for replication-related functionality in the MySQL server and command-line tools. This book doesn’t go into great depth, so don’t expect it to be a reference manual to replication internals or anything like that.

Percona Server 5.1.57-12.8 Stable Release

Released on June 8, 2011 (Downloads are available here and from the Percona Software Repositories.

Percona Server 5.1.57-12.8 is now the current stable release in the 5.1 series. It is is based on MySQL 5.1.57.

Bug Fixes

  • Fixed InnoDB I/O code so that the interrupted system calls are restarted if they are interrupted by a signal. InnoDB I/O code was not fully conforming to the standard on POSIX systems, causing a crash with an assertion failure when receiving a signal on pwrite(). Bug Fixed: LaunchPad: #764395 / MySQL bug #60788 (A. …
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SQL access to CouchDB views

Following up on my first post on an alternative, more SQL-eee metadata driven approach to doing BI on Big Data, I’d like to share an example on how we can enable easy reporting on top of BIg Data immediately for CouchDB users. We’re very keen on discussing with CouchDB/Hive/other Big Data users about their Ad Hoc and BI needs; please visit the forum thread about the connector.

We’ve been working with some new potential customers on how to leverage their investment in Big Data (specifically Big Couch provided by the fine folks at Cloudant. In particular, this prospects users are …

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A different vision for the value of Big Data

UPDATE: Think we’re right? Think we’re wrong? Desperate to figure out a more elegant solution to self service BI on top of CouchDB, Hive, etc? Get in touch, and please let us know!

There’s a ton of swirling about Hadoop, Big Data, and NoSQL. In short, these systems have relaxed the relational model into schema(less/minimal) to do a few things:

  • Achieve massive scalability, resiliency and redundancy on commodity hardware for data processing
  • Allow for flexible evolution and disparity in content of data, at scale, over time
  • Process semi-structured data and algorithms on these (token frequencies, social graphs, etc)
  • Provide analytics and insights into customer behaviors using an exploding amount of data now …
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Truly Random and Complex Password Generator - Part 1 of 2

Permalink: http://bit.ly/1pJlpHz



Skip to the 2nd part for the code snippet.

Its an important matter of security to enforce complex passwords that have a sufficient length. From personal experience, if you ask a normal user to create their own passwords, their passwords will be based on a character set consisting of 36 case-insensitive alphanumeric characters: a-z, 0-9 instead of the full 94 character set typable on all keyboard layouts. Also, most normal users would use dictionary based passwords with a predictable pattern: dictionary words at the beginning and numbers at the end.

Relying solely on the client-side or front-end to enforce the creation of passwords of at least 8 characters long and the use of …

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