Showing entries 26921 to 26930 of 44919
« 10 Newer Entries | 10 Older Entries »
Announcing TokuDB 2.1.0

Tokutek® announces the release the release of the TokuDB storage engine for MySQL®, version 2.1.0.  This release offers the following improvements over our previous release:

  • Faster indexing of sequential keys.
  • Faster bulk loads on tables with auto-increment fields.
  • Faster range queries in some circumstances.
  • Added support for InnoDB.
  • Upgraded from MySQL 5.1.30 to 5.1.36.
  • Fixed all known bugs.

About TokuDB

TokuDB for MySQL is a storage engine built with Tokutek’s Fractal Tree™ technology. TokuDB provides near seamless compatibility for MySQL applications. Tables can be individually defined to use TokuDB, MyISAM, InnoDB® or other MySQL-compliant storage engines. Data is loaded, inserted, and queried using standard MySQL commands, with no restrictions or special …

[Read more]
Why you don’t want to shard.

Note: This blog post is part 1 of 4 on building our training workshop.

The Percona training workshop will not cover sharding. If you follow our blog, you'll notice we don't talk much about the subject; in some cases it makes sense, but in many we've seen that it causes architectures to be prematurely complicated.

So let me state it: You don't want to shard.

Optimize everything else first, and then if performance still isn't good enough, it's time to take a very bitter medicine. The reason you need to shard basically comes down to one of …

[Read more]
Open source’s role in lowering the barriers to data warehousing

As well as contributing to the CAOS research practice here at The 451 Group I am also part of the information management team, with a focus on databases, data caching, CEP, and - from the start of this year - data warehousing.

I’ve covered data warehousing before but taking a fresh look at this space in recent months it’s been fascinating to see the variety of technologies and strategies that vendors are applying to the data warehousing problem. It’s also been interesting to compare the role that open source has played in the data warehousing market, compared to the database market.

I’m preparing a major report on the data warehousing sector, for publication in the next couple of months. What follows is a rough outline of the role open source has played in the sector. Any comments or corrections much appreciated:

Unlike other …

[Read more]
Cassandra database and range scans

I've been doing a little more playing with Cassandra, an open source distributed database. It has several features which make it very compelling for storing large data which has a lot of writes:

  • Write-scaling - adding more nodes increases write capacity
  • No single point of failure
  • configurable redundancy

And the most important:

  • Key range scans


Key range scans are really important because they allow applications to do what users normally want to do:

  • What emails did I receive this week
  • Give me all the transactions for customer X in time range Y

Answering these questions without range scans is extremely difficult; with efficient range scans they become fairly easy (provided you pick your keys right).

[Read more]
Installing Cherokee With PHP5 And MySQL Support On Ubuntu 9.04

Installing Cherokee With PHP5 And MySQL Support On Ubuntu 9.04

Cherokee is a very fast, flexible and easy to configure Web Server. It supports the widespread technologies nowadays: FastCGI, SCGI, PHP, CGI, TLS and SSL encrypted connections, virtual hosts, authentication, on the fly encoding, load balancing, Apache compatible log files, and much more. This tutorial shows how you can install Cherokee on an Ubuntu 9.04 server with PHP5 support (through FastCGI) and MySQL support.

Once upon a timestamp(milliseconds)….

Once upon a time`stamp`, in a `data`base far far away, someone filed a bug named: `Microseconds precision is not retained by TIME, DATETIME, and TIMESTAMP field types.` – Bug Number 8523. This was the beginning of 2005, yet now that we are approaching the end of 2009, after 4.5 years, many (including myself) are still asking for this.

In fairness sake, MySQL have indeed supplied a way to retain milli and micro seconds in a decimal field `DECIMAL(17,3)`, and it is also queryable as if it were a timestamp BUT why isn’t it possible to store in a `DATETIME` or `TIMESTAMP` field? Why can’t we run a ’select now()’ or ’select curtime()’ etc and get a full timestamp including milli / micro seconds?

I have counted 37 different usernames asking for this feature, spanning from 15th Feb 2005 to recently. (list found below)

Some have suggested UDFs, others suggested using log4j while others, pretty annoyed, allegedly went …

[Read more]
OpenSQL Camp 2009: Session schedule published - pre-register now!

I'm happy to announce that the schedule for OpenSQL Camp 2009 (European Edition) has been published on the FrOSCon timetable now. We have a great selection of topics and speakers, so don't miss it! OpenSQL Camp is a subconference of FrOSCon, the Free and Open Source Conference, which will take place on August 22nd and 23rd in St. Augustin, Germany.

The admission fee for the entire conference (both days, incl. OpenSQL Camp) is 5 EUR, you can pre-register here until August 10th (and if you do so today, you will still get a free T-Shirt as well!). Of course, you …

[Read more]
Deployment of MySQL using daemontools, XtraBackup

I am sure many people have already done similar things, but to ease my pain of setting up mysqld on a large-scale environment (I am trying to create a set of database nodes, each node consists of a MySQL failover cluster using semi-sync replication, that can be administered easily), I have just finished writing a deployment script called mysqld_jumpstart.  The caveats are:

  • integration with daemontools (mysqld is automatically started)
  • setup of masters and slaves
  • can setup slaves from backup data generated by XtraBackup

The last feature was the one I especially needed, since thanks to the people at Percona, things have become much …

[Read more]
Does your host flush?

While investigating a friend’s report of ext3/InnoDB corruption in a Ubuntu VirtualBox guest, when his OS X host machine crashed, I discovered that by default, VirtualBox does not do anything about IDE Flush Cache commands. The natural implication of this, which I have been able to reproduce, is that your journaled and transactional guest systems cannot maintain integrity if the host crashes. (For longer reasoning see that forum post.) It’s as if you were running them on broken hardware. This can corrupt InnoDB – which under normal circumstances recovers fine from crashes. You can imagine what it could do to MyISAM So this post is just a headsup – even if you’re only doing development in VB – unless you want to risk nasty surprises, I strongly recommend you disable the IgnoreFlush option in VirtualBox. See “Responding to guest IDE flush requests,” in the VirtualBox manual. This issue may also affect other virtualisation hosts. While …

[Read more]
MySQL Proxy: profiling 0.8

In MySQL Proxy 0.8 we are added a multi-threaded network-subsystem allowing several networks events be processed in parallel. Early benchmarks show that what we have in trunk basicly works.

But the benchmarks weren’t as good as we expected. That’s the time where you prepare to get dirty.

While Kay went with lockstat to analyze the proxy on solaris and found that g_atomic_int_get() isn’t using native code if built with Sun’s CC, I attacked the Linux side with oprofile.

After rebuilding the proxy with -fno-omit-frame-pointer I got the information I was looking for from oprofile:

$ opcontrol --vmlinux=...
$ opcontrol --callgraph=5
$ opcontrol …
[Read more]
Showing entries 26921 to 26930 of 44919
« 10 Newer Entries | 10 Older Entries »