There is patch from Google to improve SMP performance , but for some
workloads it showed for us reverse scalability.
E.g. update_key benchmark from sysbench. There are also results
with Yasufumi's rw_locks (http://bugs.mysql.com/bug.php?id=26442)
| Threads | Standard InnoDB | Google smpfix | Yasufumi rw_lock |
| 1 | 9700.28 | 10601.96 | 9432.44 |
| 2 | 14355.66 | 16673.31 | 12783.58 |
| 4 | 16104.20 | 2669.39 … |
Today's "commercial quality disks" are amazing but they
follow the same limitations as yesterday's disks. mySQL scales
very well, but disks do not. So if you're IO bound when will your
expectation of speed fail?
Test setup:
DELL 2950 PERC-6 HWRaid BBC 6 DISK 15K RPM 3.5" RAID-10 256K
stripe across two channels-using WRITE THROUGH CACHE on mkfs.ext3
-T largefile4 Linux Filesystem.
The theory is that the outer part of the spindles is the fastest,
and the inner portion is slower - since the outer is where the
data starts (thanks for the info Benjamin Schweizer). Thus one can conclude that
the more disk space your application(s) use the slower the
throughput, since the heads have to move more. Brad F. my
co-worker did a benchmark to prove this. Our goal …
I just thought I would share some of my discoveries. You may
already have known this but I didn't.
In recent releases both the PBMS and PBXT engines have been using
a configuration flag "--with-mysql" to tell the build where to
find the MySQL tree. We then looked inside the 'config.status'
file generated when MySQL was configured to get the build
options, most importantly the compiler options used. We had been
doing this using 'grep' and 'sed'. The problem we soon discovered
was that the format of the 'config.status' file changes quit
frequently with different versions of 'autoconf'.
With the help of the good people on the 'autoconf' forum I
discovered that you can ask 'config.status' to give you the value
of a single substitution. So to get the value for CFLAGS you
enter: echo '@CFLAGS@' | config.status --file- and it will print
out a line with the CFLAGS.
I understand that this feature which has always existed is now
being …
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On Saturday, October 25th, I will be speaking at a Linux Day event in Sassari, about 200 Km from my hometown. The Linux Day is a global event in Italy. At a given date, all participating towns host a Linux gathering, which could be a conference, a workshop, an install fest, or all of the above. I am speaking at the Linux Day in Sassari, on the subject of Open Source in the enterprise. Theory and practice. It will be a talk on what enterprises should do with open source, to improve individual and team work, and what individuals can do to work better in an open enterprise. |
I am starting a trip of two days to Munich to attend tomorrow, October 21st 2008, the MySQL™ Central EU Customer Conference.
And.. sure! I am still wondering why I am coming stated that I
don’t understand German :-/
I thought that the Conference was in English or at least part of
it but.. eh eh eh.. it seems it isn’t.
Two things deceived me. The name “Central Europe” and the possibility to come with some friends which are used to go in Germany in this period to drink liters of beer.
Possibility no. two vanished cause one of them went away to U.S. for a short period @ Standford University and the others are very busy during this week.
Moral:
Stop the press! My boss, Stefan Hinz, has just started blogging, with his first post here: Using NetBeans with MySQL.
So who is he? Well, Stefan is the guy that keeps the rest of us in the docs team in check and makes sure we do what we’re asked, when we’re are asked and that all of the machinery, legalities and management tasks happen in the background. Without him we really couldn’t function as effectively as we do.
It’s wonderful to see some other Docs team members getting in on the act (to be fair to the rest of the team, Jon is also a blogger). We are all writers, you would think the blogging would come as a natural extension.
Behind the tease is the simple fact that the improved system for MySQL University I was talking about is getting a trial run this week. …
[Read more]The next MySQL University session will take place this Thursday, 23rd October. David Van Couvering will show how to use NetBeans with MySQL.
Note that this session will start at 9:00 Pacific Time (18:00 CET, 17:00 BST).
For this session, we'll use a new presentation system that we hope will make things much easier for both presenters and attendees: Dimdim (www.dimdim.com). If it works out as expected, Dimdim will replace our current presentation system which required attendees to open a browser, connect to an IRC channel on Freenode, and open some fancy URL with a voice streaming application. With Dimdim, all that needs to be done is point your browser to a URL, and that's it. …
[Read more]
One day we'll change some defaults to be more realistic, but in
the meantime, please make sure you have set
your FragmentLogFileSize and NoOfFragmentLogFiles to
something big! Like, if you have 20Gb, set it the size to 256Mb
and number of log files to 176, something like that (watch the
diskspace though!). The thing his, if you need to restore your
backup, you will run into problems and it just takes time,
precious time to get it back up!
Anyway, those are not the only ones, and those hard hard to set
later on (needs initial node restart, rolling though).
More in our all mighty manual and Johan's
configuration tool.
I recently attended an interesting talk by Brion Vibber, CTO of
WikiMedia
Foundation, a non-profit organisation that runs the
infrastructure for Wikipedia. He described how his team of 7
engineers manages the Wikipedia site that gets on an average of 7
billion page views per month. The highlights from the talk are
listed below that included the architecture of the site
infrastructure to scale up to the traffic that is received. They
are ranked amongst the Top 10 sites in terms of traffic.
The site runs on the LAMP stack and you know what that is:
WikiMedia runs the site on about 400 x86 servers. Of those, about 250 run the webservers and the remaining run MySQL database. Recently they acquired the …
[Read more]
As part of an internal programme at Sun, I am a “SEED
mentor” for another Sun employee (not a former employee
of MySQL, but what we Sun Dolphins call Sun Classics). He is
called Alok and lives in Bangalore, and sadly, our schedules
crossed so that I couldn’t meet him when I was at our Bangalore
offices in July. So I am mentoring someone I’ve met only over
phone — but we’re getting along just fine.
Two of the topics we’ve discussed recently are blogging and books. So after hanging up after our 9 CET 12:30 Indian time mentoring session, I got the idea to combine the two: write a blog entry about the books I recommended Alok.
One thing Alok is contemplating at the moment is the degree to which he should spend time on developing his business skills vs his engineering skills. That’s a familiar topic for many of us in …
[Read more]