Installation of a GCB node

1. Description

This node will serve as a Generic Connection Brokering (GCB) node. If you are working over firewalls or NATs, you will need one or more of these.
GCB is needed every time you have a firewall or a NAT; if this node dies, all the glideins relying on it will die with it.

2. Hardware requirements

This machine needs a reasonably recent CPU and a small amount of memory (256MB should be enough).
It must have reliable network connectivity and must be on the public internet, with no firewalls; it will work as a router. It will use 20k IP ports, so it should not be collocated with other network intensive applications.
The machine must be very stable; if the GCB dies, all the glideins relying on it will die with it (You can use multiple GCBs to minimize the damage, but you should still try to choose the stablest machine you can afford.)
The disk needed is just for Condor binaries and log files (5GB should be enough)

BTW: As low spec machine could be difficult to find, please consider collocating it with a VO Frontend.

3. Needed software

A reasonably recent Linux OS (SL4 used at press time).
The Condor distribution.

4. Installation instructions

The GCB should be installed as a non privileged user, for example the user gcbuser.

Move into

glideinWMS/install

and execute

./glideinWMS_install

You will be presented with this screen:

What do you want to install?
(May select several options at one, using a , separated list)
[1] glideinWMS Collector
[2] Glidein Factory
[3] GCB
[4] pool Collector
[5] Schedd node
[6] Condor for VO Frontend
[7] VO Frontend
[8] Components

Select 3.

Now follow the instructions and install all the software components.

The installation is straightforward, as can be seen in the snaphot locate in gcb_install_snapshot.txt.

4.1 Verify it is running

You can check that the processes are running:

ps -u gcbuser |grep gcb

You should see one gcb_broker and at least one gcb_relay_server.

You can also check that tey are working well, by pinging it with gcb_broker_query:

~/gcbcondor/sbin/gcb_broker_query your_ip freesockets




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