Re: [HTCondor-users] schedd on every submit node VS single schedd

[Greg Thain <gthain@xxxxxxxxxxx>]

On 11/19/18 5:35 AM, David Cohen wrote:
> Hi,
> I'm starting an HTCondor system for the first time, to replace a 
> torque/maui cluster, and trying to figure out the basic topology 
> before I start.
> What is the benefit of having a schedd on every submit node vs single 
> schedd.


I am glad you asked this question, as it touches on fundamental aspects 
of HTCondor.


The first reason to have multiple schedds it to scale up. HTCondor is 
designed to have a lightweight central manager that merely provisions 
resources to users, with most of the expense of job management happening 
at the edge, in the schedds. If you have a single submit machine with 
enough power to handle all of your idle and running jobs, there is less 
reason to have more than one schedd.

Another reason to have multiple schedds is data locality. If you are 
transferring large input sandboxes to run your jobs, perhaps you want to 
put your schedds near the source of the input files.

A common reason to have multiple schedds is administrative control. 
There are a lot of policy knobs that an administrator can set in the 
schedd, and if your organization contains sub-organizations, each with 
different policy goals, sometimes it is easier and clearer for each 
sub-domain to have their own scheduler to work with.


-greg