The VM for Linux prefers system cache over application memory.
What does this mean? The best way I can explain is by
example.
Imagine you have 32 GB of RAM
MySQL is set to take 20 GB of RAM for a process based buffer and
up to 6M for the various thread buffers.
Over a period of time the box swaps. The only thing that is
running is mysql and its memory size is around 21GB for resident
memory. Why does swap grow when there is plenty of memory? The
reason is when a memory alloc is needed (thread based buffer is
tickled) the VM will choose to use swap over allocating from the
system cache, when there is not enough free memory.
DO NOT TURN OFF SWAP to prevent this. Your box will crawl, kswapd
will chew up a lot of the processor, Linux needs swap enabled,
lets just hope its not used.
So how do you stop Nagios pages because of swap usage? Well if
you have a few choices.
…
Ever since Peter over at Percona wrote about MySQL and swap, I’ve been meaning to write this post. But after I saw Dathan Pattishall’s post on the subject, I knew I’d better actually do it.
There’s a nasty problem with Linux 2.6 even when you have a ton of RAM. No matter what you do, including setting /proc/sys/vm/swappiness = 0, your OS is going to prefer swapping stuff out rather than freeing up system cache. On a single-use machine, where the application is better at utilizing RAM than the system is, this is incredibly stupid. Our MySQL boxes are a perfect example – they run only MySQL and we want InnoDB to have a lot of RAM (32-64GB …
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I like Ubuntu's philosophy. Among the Debian derived Linux
distros, it's the one that appeals to me the most. The first live
CDs (Knoppix, Mepis) were a revolution, but Ubuntu has perfected
the trend by adding a quality that was missing from these early
ones.
I especially like the ease of installation. Plug to the net,
apt-get install package_name, and presto! you got what you
want.
MySQL server comes with just one line:
apt-get install mysql-client mysql-server
This will get you the latest server and client binaries, ready to
use.
Yesterday I wanted to build MySQL 5.1 from source. The latest one
(5.1.24) that has been released is missing the Federated engine,
and I wanted the complete thing. So I installed Ubuntu in a spare
machine, and got the source code from the development
tree.
By …
It is perhaps fitting that the last word on the recent MySQL licensing row should belong to Sun’s CEO, Jonathan Schwartz. In a twitter Q&A with Web 2.0 Expo attendees, courtesy of Tim O’Reilly, he states that:
“we have no plans whatever of ‘hiding the ball,’ of keeping any technology from the community. Everything Sun delivers will be freely available, via a free and open license (either GPL, LGPL or Mozilla/CDDL), to the community.
Everything.
No exception.”
Which would appear to be pretty conclusive, despite his additional claim that “leaders at Sun have the autonomy to do what they think is right to maximize their business value - so long as they remember their responsibility to the corporation and all of its communities (from shareholders to developers). Not just …
[Read more]This article describes how to install the Drupal 6.2 CMS on MySQL 6.0, using the Falcon Storage Engine. The operating system is a default Ubuntu 8.04 "Hardy Heron" (x86) installation.
I will make a few assumptions here, in order to keep the instructions simple: a fresh OS install, no other MySQL databases or web services are running or have already been installed. Both MySQL and the web server are installed on the same host. You should be able to become root to install packages and to have access to the local file system and the system configuration.
This article will explain how to install and configure Apache/PHP, MySQL 6.0 and …
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Well, I decided to take the plunge and migrate from Windows XP to
Ubuntu. Now, technically, I have been wanting to do this for a
while, but I was dependant on my windows to dial up to my
internet (some problem with my ISP here). I tried to do it in
Ubuntu a few months ago, but it was too complicated for me.
However, it left me with a yearning to try again.
So, I waited for the new Ubuntu to come out and in parallel fixed
my router.
Why?
The reason I thought it was a good idea to move to linux was
mainly for self-improvement.
I recently read some blogs (couldn't find them now) that
mentioned that with all the new web apps, there will be less and
less emphasis on the OS. In 2011 (gartner says), this will hit a
crucial point.
I was thinking, maybe more people will adopt free linux when
everything important will be in "the cloud" and all you really
need is a browser anyway. So I know how to use linux, I …
I happened to need an extra Linux install on one of my
computers.
I went to my local Ubuntu mirror (under network installer) and
downloaded the files 'linux' (kernel) and 'initrd.gz'.
Copied them to random directory on the existing Linux
install.
Rebooted, and typed 'c' in Grub to get a command line.
Entered the three commands kernel <path to linux>, initrd
<path to initrd.gz> and boot.
Went quickly through the installer, downloading packages from a
mirror and installing the sshd server.
Hey presto, Linux install in maybe 15 min or so? No fiddling with
burning and juggling CD/DVD, which I really hate. Grub + network
installer is a piece of genius.
(For an initial install, I usually boot from network, downloading
the two above files by tfpt from another computer on the network,
which is only slightly more involved and still avoids any …
Agenda:
* The state of open source venture funding
* What’s up with MySQL?
* Desktop Linux troubles
* Qlusters stepping away from open source
* OSI Board election
* Open source social - centralized or distributed?
* The Open Source Census
iTunes or direct download (37:31, 8.6MB)
I really thought I was done writing about MySQL for a while, but I attended a Sun/MySQL event in London today and have some shocking news to impart. It seems we’ve got MySQL all wrong.
At the event, MySQL co-founder David Axmark talked through some of the history of the MySQL project and company, confirming what has previously been reported about the origins of the database’s name.
It was, he confirmed, named after co-founder Monty Widenius’s daughter, My. …
[Read more]JFYI, I now placed a PDF of my MySQL Conference talk slides about "Performing MySQL backups using Linux LVM Snapshots" on my MySQL talks page. Enjoy!