Tuesday, March 15, 2011

Projects for Distributed Systems Lab

These projects are fundamental for creating a computational ecosystem in which vast majority of networking management tasks could be automatized. For portability, the services and tools must be deployed on virtual machines.

Network services
  • DHCP Server
  • DNS Server
Deployment services
  • Fedora mirror
  • Cobbler/koan
Services to enable remote access
  • Tools to support remote monitoring via remote terminal as well as browser interface
    NOTE: wake-on LAN service would be enable in all machines at lab
Repository services
  • Git tool
Security tool
  • To search, evaluate and select a network intrusion detection tool
There would be two operating systems in the lab
  • CentOS would be the Linux distro in which cobbler/koan service would reside
  • Ubuntu server would be used to deploy DNS, DHCP and Git programs along with a network intrusion detection tool.
Repositories for both environments would be required. Only last releases would be maintained.

Thursday, March 10, 2011

Text-based network monitoring tools...

I want share some projects that I found very useful when you require to monitor you network activity. Those projects are not so much sophisticated but very useful for figuring out how and who is consuming your network bandwidth.
  • iptstate this program presents connections "observed" by iptables
  • speedometer is a python script to show in real-time how much bandwidth is consumed by a network interface. It discriminates between download and upload bandwidth consumption. How to use it: 'speedometer -rx <network-interface> -tx <network-interface>'
  • pktstat "displays a real-time list of active connections seen on a network interface, and how much bandwidth is being used". How to use it: 'pktstat -i <network-interface>'
<network-interface> could be wlan0, eth0, ppp0, and so on.


Wednesday, March 2, 2011

Booting order during the deployment process... [CETA-CIEMAT]

The booting order during the deployment of a computing ecosystem which provides grid computational services using the OCD-gLite script is first working nodes(WN) then computing element (CE).
That is it because access permissions with no password is required for job submission and those permissions are set up by CE and it requires that all working nodes be up and running.

Submitting jobs to maui

For submitting jobs from the computing element
  • Login as a user different of 'root'. In particular, when a computing element has been deployed with the OCD-gLite, it comes with a lot of user. Try 'ceta000'.
  • Create a basic bash script
    Change its permissions as follows "chmod +x script.sh"; assuming that the script has been named as 'script.sh'
  • Submit the job, executing 'qsub -q ceta script.sh'. '-q ceta' indicates that this job would be enqueued to one queue named 'ceta'. 
  • If everything works as it is expected, a file called 'script.sh.o0' must contain something. ;-)
This notes were taken during my stay at CETA-CIEMAT and the information provided here is only relevant for usage scenarios experimented there.

Building dependencies for a Fedora package...

These days, I was "engaged" with a project named libguestfs. My box runs Fedora 13 and current version is Fedora 14. Therefore some packages are oldie and particular software requirements are necessary. For installing 'libguestfs' in my system, considering all the software ecosystem that it needs, this yum command is very useful.

# yum-builddep libguestfs

It, as its name suggests, prepares all the dependencies for the libguestfs package.

When you need to install a package which requires a lot of dependencies and you want avoid the cumbersome process of install one by one dependency, then try this command first.