Microsoft contributes to Linux. Acquia raises $8m. And more.

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Microsoft contributes to Linux
Microsoft announced that it is to contribute device driver code to the Linux kernel under the GPLv2. Prompting us to publish a CAOS Theory Q&A. Answering one questioning we failed to ask, ZDnet reported that Microsoft’s Linux contributions should find their way into the 2.6.32 release.

Acquia raises $8m
Mass High Tech …

Dear community,

Today we are pleased to announce release 6 of XtraDB - the result of 2 months hard work.

The release includes following new features:

• MySQL 5.1.36 as a base release
• New patch innodb_recovery_patches.patch
• Experimental adaptive checkpoint method estimate
• innodb_stats - the implementation of the fix forMySQL Bug#30423
• expand-import Support of import InnoDB / XtraDB tables from another server
• split-bufpool-mutex-3 New patch to split buffer pool mutex
• …

There was small delay in our releases, part of this time we worked on features I mentioned before:
- Moving InnoDB tables between servers
- Improve InnoDB recovery time
and rest time we played with performance trying to align XtraDB performance with MySQL 5.4 ® and also port all performance fixes to 5.0 tree.

So basically we made: new split-buffer-mutex patch, which separate global buffer pool mutex into several small mutexes, and ported some Google IO fixes.
Here are results what we have so far. As usually for benchmarks I used our workhorse Dell PowerEdge R900 with 16 cores and 32GB of RAM and RAID 10 on 8 SAS disks. And again as usually our tpcc-mysql scripts with 100W …

Speed of InnoDB recovery is known and quite annoying problem. It was discussed many times, see:

http://bugs.mysql.com/bug.php?id=29847

http://dammit.lt/2008/10/26/innodb-crash-recovery/

This is problem when your InnoDB crashes, it may takes long time to start. Also it affects restoring from backup (both LVM and xtrabackup / innobackup)

In this is simple test, I do crash mysql during in-memory tpcc-mysql benchmark with 16 running threads.
MySQL params are:

PLAIN TEXT CODE:

1. innodb_buffer_pool_size=16G
2. innodb_log_files_in_group=3
3. innodb_log_file_size=512M

So let's take standard MySQL …

Seen in #maatkit on Freenode:

I never realized just how terrible recovering MyISAM from a crash can be

Sad but true — it can be pretty painful. This is one of the reasons I pretty much recommend InnoDB (okay, okay, XtraDB) for most data unless it’s read-only.

Related posts:

1. Hindsight on a scalable replacement for InnoDB A while ag
2. What is the scalable replacement for InnoDB? A while ba
3. Xtrabackup is for InnoDB tables too, not just XtraDB Just thoug

Related posts brought to you by …

This is probably the feature I missed most from early days when I started to use InnoDB instead of MyISAM. Since that I figured out how to survive without it, but this is first question I hear from customers who migrated from MyISAM to InnoDB - can I just copy .ibd files from one server to another and answer "use mysqldump" is quite disappointed.
Jokes aside, I see real needs in this:
- when we need to restore only single table from backup (sometimes developers kill only single table, not whole database )
- to copy single table from production to QA environment. It may sound not so important, but I see needs in this quite often. QA boxes may have their own setup, not so powerful and with not enough space, but QA still needs to have some tables in fresh status.
- resharding databases, moving some shards from one server to another.

So long story short end - we made new mode for XtraBackup, now it can copy and …

Just thought it was worth pointing out that Percona Xtrabackup is not just for XtraDB. It works great for InnoDB tables, too.

So if mysqldump can’t handle it anymore, LVM snapshots kill your server and you don’t want to buy proprietary backup software, you might take a look at Xtrabackup.

Related posts:

1. Hindsight on a scalable replacement for InnoDB A while ag
2. Restoring from a mysqldump into tables with triggers This is ac
3. What is the scalable …

Last week we were busy to align XtraDB performance with 5.4, now we have some results. Currently it is available as "hacks" to XtraDB (available on Lauchpad lp:~percona-dev/percona-xtradb/hacks-porting-tune if you are interested). Basically we took improvements from 5.4 and backported ones performance related to XtraDB.

Here are results for tpcc-like workload, 100W (~10GB) ( raw results and parameters are available here
http://spreadsheets.google.com/ccc?key=rxUEhM2dqbX0uAfq9j6WQ_w ). Box Dell PowerEdge R900 (Does Dell have referral program ? ), with RAID10 (8 disks) on ext3, 32GB of RAM.

As you see there almost no difference and you may say what's the reason in XtraDB ? The most interesting reason is XtraDB based on InnoDB-plugin and contains its nice features like FAST INDEX CREATION and dynamic pages. And XtraDB has some …

A while ago I posted about a comment a Sun performance engineer made about a scalable replacement for InnoDB. At the time, I did not believe it referred to Falcon. In hindsight, it seems even clearer that the Sun performance experts were already working hard on InnoDB itself.

Sun’s engineers have shown that they can produce great results when they really take the problems seriously. And I’m sure that InnoDB’s performance has untapped potential we don’t see right now. However, it does not follow that their work on InnoDB is what was meant by a scalable replacement for InnoDB. Or does it?

General-purpose MVCC transactional storage engines with row-level locking, whatever their performance and scaling characteristics in …

As continue to my benchmarks http://www.mysqlperformanceblog.com/2009/04/30/looking-on-54-io-bound-benchmarks/ on 5.4 I tried in-memory load (basically changed buffer pool from 3GB to 15GB, and database size is 10GB). The results are on the same spreadsheet http://spreadsheets.google.com/ccc?key=rYZB2dd2j1pQsvWs2kFvTsg&hl=en#, page CPUBound.

I especially made short warmup (120 sec) and long run (2700sec) to see how different versions go through warmup stage.

The graph is

In default mode I would say XtraDB performs almost the same as 5.4, but dips are a bit worse than in 5.4.

Now about dips - all of them are caused by InnoDB checkpoint activity, InnoDB is doing intensive flushing of …