Elliott A. Johnson elliott at
Tue Apr 1 20:48:58 UTC 2008

Hi Andrew,

I've found the documentation to be sparse as well.  I'll try my best to help you out though.

> There has to be documentation somewhere on Perlbal, right? 

With the source code there are several text files describing the configuration of perlbal.  There is config-guide.txt which gives commands that are used in the perlbal.conf as well as in the management interface.  To access the management interface you can telnet to the configured host + port and type one of the commands from the config-guide (... 'help' is a good place to start).

To dig deeper into the config there is the service-parameters.txt file which explains much of the service configuration details.

> What the different roles are, 

Looking at the file it says this about service roles:

     'role' => {
        des => "What type of service.  One of 'reverse_proxy' for a service that load balances to a pool of backend webserver nodes, 'web_server' for a typical webserver', 'management' for a Perlbal management interface (speaks both command-line or HTTP, auto-detected), or 'selector', for a virtual service that maps onto other services.",
        required => 1,

>From what I've seen upload_tracker is a role as well not mentioned here, but documented here:

> how the management server works,

You can view it via a web browser and interact with via telnet from what I've gathered.  I was really hoping there would be a good status page which when queried reports "OK" or "Service foo has failed.".  For now I'm parsing the /socks page.

> what the difference between random and round-robin load balancing is, 

I believe this is explained in other areas like wikipedia, but as I understand it round robin scheduling cycles through a list of hosts.  Random grabs the list of hosts, looks at how many elements are in the list, and generates a random index and selects the list element at that index.  Someone please correct me if I'm wrong.

> Am I missing something obvious?

Nope, I agree with you.  If perlbal would like some "getting started" documentation, I'll write something up. 

> Best, 
> Andrew McClain 



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