Pomme::TAB

1. Environment

I used 4 Xen virtual images running ubuntu 8.04.
Two will run a tracker and the database, the other two will be the storage nodes.

Lets say the IP addresses will be:


192.168.0.195
192.168.0.196
192.168.0.197
192.168.0.198


2. Initial Setup

Install iptables:


apt-get install iptables


then apply initial setup


iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --dport ssh -j ACCEPT
iptables -A INPUT -j DROP
iptables-save -c > /etc/iptables.rules

you can save the rule for beyond machine reboot by adding the two lines below to /etc/network/interfaces

pre-up iptables-restore < /etc/iptables.rules
post-down iptables-save -c > /etc/iptables.rules


install mysql and wget and perldoc


apt-get install mysql-server
apt-get install wget
apt-get install perl-doc
apt-get install libio-aio-perl
apt-get install subversion
apt-get install build-essential


3. Common steps for installing MogileFS

retrieve the code (ripped of the how to wiki):


cd /usr/local/src
mkdir mogilefs-src
cd mogilefs-src
svn checkout http://code.sixapart.com/svn/mogilefs/trunk


install perl dependencies


cpan Danga::Socket
cpan Gearman::Client
cpan Gearman::Server
cpan Gearman::Client::Async
cpan Net::Netmask
cpan Perlbal
cpan IO::WrapTie


install the servers:


cd mogilefs-src/trunk/server
perl Makefile.PL
make
make test
make install


At the moment the test seems to need mysql to be installed and user root without password, so some tests are skipped

you will need to install MogileFS::Client
(the tests expect a tracker to run locally on port 7001)


cd mogilefs-src/trunk/api/perl/MogileFS-Client
perl Makefile.PL
make
make test
make install


and some admin tools:


cd mogilefs-src/trunk/utils
perl Makefile.PL
make
make test
make install


4. Tracker install

create the database:


mysql -uroot -p
mysql> CREATE DATABASE mogilefs;
mysql> GRANT ALL ON mogilefs.* TO 'mogile'@'%';
mysql> SET PASSWORD FOR 'mogile'@'%' = OLD_PASSWORD( 'sekrit' );
mysql> FLUSH PRIVILEGES;
mysql> quit


Create the schema


./mogdbsetup --dbname=mogilefs --dbuser=mogile --dbpassword=sekrit


(admin privilege is required for the initial setup, so if you’re admin user is not root with no password, you will need to specify –dbroopassword and –dbrootuser)

create /etc/mogilefs/mogilefsd.conf:


db_dsn DBI:mysql:mogilefs
db_user mogile
db_pass ******
conf_port 7001
listener_jobs 5


create a mogile user:


adduser mogile


and starts the tracker under that user:


su - mogile
mogilefsd


open a port for the tracker


iptables -A INPUT -p tcp --dport 7001 -j ACCEPT
iptables -F


5. Storage node

On the storage server, create a configuration file at /etc/mogilefs/mogstored.conf with the following:


httplisten=0.0.0.0:7500
mgmtlisten=0.0.0.0:7501
docroot=/var/mogdata


open a port:


iptables -A INPUT -p tcp --dport 7500 -j ACCEPT
iptables -F


register a new storage node:


mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001 host add mogilestorage --ip=192.168.0.197 --port=7500 --status=alive


it should now appears in the list:


mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001 host list


Add a device to the storage:


mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001 device add mogilestorage 1


and create the directory:


mkdir -p /var/mogdata/dev1


6. Starting the storage server

as root:

mogstored --daemon


7. Starting the tracker


su - mogile
mogilefsd -c /etc/mogilefs/mogilefsd.conf --daemon
exit


8. Testing

check that mogilefs components are online:


mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001 check


Quick sanity check of the storage daemon:


~/Projects/mogilefs $ telnet 192.168.0.197 7500
Trying 192.168.0.197...
Connected to 192.168.0.197.
Escape character is '^]'.
PUT /dev1/test HTTP/1.0
Content-length: 4
\n
test
HTTP/1.0 200 OK
Content-Type: text/html
Content-Length: 18
Server: Perlbal
Connection: close
200 - OK
Connection closed by foreign host.


create a domain


mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001 domain add mydomain


and a class


mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001 class add mydomain images


Quick sanity check of the tracker:


root@bbc-01:~# mogtool --trackers=127.0.0.1:7001 --domain=mydomain --class=images inject osname osname


on the store node, check /var/mogdata/dev1/0/000/000 for a file named xxxxxxxxxx.fid .
If the file exists it’s all good.

9. setting up the second pair

Replay instructions 1 to 8, then:

when you’ve got the second storage set up, you will need to register the second storage and its device to all trackers:


mkdir -p /var/mogdata/dev2
mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001 host add mogilestorage2 --ip=192.168.0.198 --port=7500 --status=alive
mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001 device add mogilestorage2 2
mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.196:7001 host add mogilestorage2 --ip=192.168.0.198 --port=7500 --status=alive
mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.196:7001 device add mogilestorage2 2


you will also need to register the first storage and its device to the second tracker:


mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.196:7001 host add mogilestorage --ip=192.168.0.197 --port=7500 --status=alive
mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.196:7001 device add mogilestorage 1


sanity check the installation:


mogadm --lib=/usr/local/share/perl/5.8.8 --trackers=192.168.0.195:7001,192.168.0.196:7001 check

Checking trackers…
192.168.0.195:7001 … OK
192.168.0.196:7001 … OK

Checking hosts…
[ 1] mogilestorage2 … OK
[ 2] mogilestorage … OK

Checking devices…
host device size(G) used(G) free(G) use% ob state I/O%
—- ———— ———- ———- ———- —— ———- —–
[ 1] dev2 9.921 0.757 9.164 7.63% writeable 0.0
[ 2] dev1 9.921 0.600 9.321 6.05% writeable 0.0
—- ———— ———- ———- ———- ——
total: 19.842 1.357 18.485 6.84%

And voila.

This week in my current project I’ve come across two ruby constructs that were new to me.

with_scope and returning.

Found a blog where they are both nicely explained:

• with_scope
• returning

Firefox users have been able to use microformats-enabled web sites (like the schedules on Upcoming or BBC Programmes) for a long time thanks to a couple of extensions (Operator and Tails Exports).

Now coming alongside the release of Safari 3.1, there’s a new Safari plugin that allow the parsing of microformats for integration in various Mac OS X applications (Adress book, iCal).

For Mac OSX users, the integration with Address Book and iCal could make Safari a better microformat reader than Firefox. I cannot test the plugin myself as I don’t have Leopard which is a requirement.

Alternatively the latest version of my feed reader NetNewsWire can also parse microformats but it requires you (obviously by the very definition of microformats) to render the web page in Netnewswire not just the summary.

Safari 3.1 is available for Tiger and Windows though.

A funny but familiar comic strip

Your Company’s App: “Company’s”

(Via Daring Fireball.)

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The Open letter from Opera’s CTO published in The Register has given me the opportunity to drawn this blog under the total wisdom of yet another pie chart as buried in the comments to the article, I found this:

You’ll notice it’s in the same vein as that one from last year

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For reasons outside my control I have to keep development branches open for a long time and therefore I need to sync them regularly with trunk and these merge operations are quite annoying and source of headaches.

Additionally, in the recent months I found myself coding disconnected from a network more often than before and I wished I could commit my changes locally and sync them when back online.

Some perl developers around me have played with SVK in the past, and at the end of last year I came across a blog post reviewing several Distributed Version Control System (DVCS).

And Let’s not forget DARCS.

I’ll play with a couple of these, but my choice may be simpler as two developers in my team have already started using Git with the git-svn hook between themselves.

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It’s a nice change after years of perl.

There are quite a few little things that I knew how to do in perl, that I didn’t have clue on how to do it in Rails. Also I run into issue peculiar to Rails or ruby.

I solved all these issues so far and the links below give pointers to some helpful information.

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In the meantime, Rufus Cable pointed me to the direction of Matisse Enzer who wrote a tool to output perl test report into the junit xml format used by Apache Ant.

If you’re not sure what’s the difference between a controlled vocabulary, a taxonomy and a thesaurus, this blog article is quite good at clarifying the above concepts and more.

What’s not covered are tags and folksonomy.

Interesting article on Boing Boing about Google image labeler and how to entice the mass into a dull job by the means of a game challenge…

It’s a clever way to do retrospective tagging. Organizations with large archives of data are likely to do more of this in order to open access to their “long tail”.

In a non-digital world, an analogy could be the way the BBC organized national “treasure hunts” to retrieve long missing archive material, except they were one-offs.

Google has found a way to harness the power of the mass (and no, this has nothing to do with what happens to humans in the Matrix trilogy, although …)