grb_rs on non-default port

[T.]

I want to start grb_rs on a non-default port. I added PORT=22222 to the license file. I checked that grb_rs is running on this port. When I execute gurobi_cl --server=127.0.0.1 --status , it tries to connect to port 61000. How can I change the port that gurobi_cl uses?

I am using Gurobi 6.0.3 on linux.

[Renan Garcia]

Please see http://www.gurobi.com/documentation/6.0/refman/firewalls.html for details on how to use non-default ports with Gurobi Remote Services. In particular, you must include a PORT= statement in both the client and server license files to choose a different *range* (e.g., when setting PORT=22222, Gurobi Remote Services would use ports 22222-24222 instead).

On Apr 11, 2015, at 8:32 AM, T. <luft...@gmail.com> wrote:

I want to start grb_rs on a non-default port. I added PORT=22222 to the license file. I checked that grb_rs is running on this port. When I execute gurobi_cl --server=127.0.0.1 --status , it tries to connect to port 61000. How can I change the port that gurobi_cl uses?

I am using Gurobi 6.0.3 on linux.

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[T.]

For debugging purposes, this is on the same host. So $GRB_LICENSE_FILE is always pointing to the same file. Still, the server listens on port 22222 (checked with lsof -i ), while gurobi_cl --server=127.0.0.1 --status says:
Unable to connect to Remote Services on '127.0.0.1' (port 61000).
Also, strace tells me that it is really trying to connect to port 61000.

[Greg Glockner]

Currently, the only way to set a non-default port with the command-line is to set everything in the license key file; if you set --server=something, then it will only use the default port.

[T.]

Ok, thank you for the information.

[T.]

Is there a way to set up a worker pool through the license key file? I want to use the distributed mip feature, not a gurobi compute server.

Or is there maybe another way to do distributed mip on a non-default port (e.g. through C API)?

[Ed Rothberg]

You can use a non-default port if you include a PORT= line in both the client and server license files.

Ed

[T.]

I guess, we misunderstand each other. I want to solve a MIP using the distributed MIP feature from the command line on a non-default port. How can I do this using gurobi_cl?

I start the workers using grb_rs on 2 nodes. They listen to port 22222 (checked via lsof -i). If I then say:

gurobi_cl TimeLimit=7200 WorkerPool=host1,host2 DistributedMIPJobs=2 Threads=8 miplib2010/air04.mps.gz

it tries to connect to port 61000 (checked via strace). PORT=22222 is set on all machines in $GRB_LICENSE_FILE.

If there is a C API call that can start distributed MIP on a given port, I could also write a small C program, but I didn't find such an API call.

[Ed Rothberg]

I want to solve a MIP using the distributed MIP feature from the command line on a non-default port. How can I do this using gurobi_cl?

I took a careful look, and you are right that this isn't possible in 6.0.  We've never actually heard of anyone using an alternate port in Compute Server, so we didn't take the time to add that feature for distributed MIP.  I have added it for our next release, though (and confirmed that it works).

Can you tell me why you need to use an alternate port?  As I mentioned, you may be the first person to have told us that they needed this.

Ed

[T.]

Thanks Ed!

On our cluster, gurobi sometimes fails to open a socket. I could not really figure out why, so I wanted to try some different ports. Maybe something else is using this port.

Do you already have any plans when this new version will be released?

[T.]

I now use LD_PRELOAD to redirect the connections to other ports. This seems to work.