Kestrel for the NEOS Server
Kestrel is an interface to the NEOS Server that allows remote access to the
solvers from a user's locally installed AMPL or GAMS modeling environment.
It provides an easy mechanism for users to submit jobs to the NEOS solvers
and receive the results within a local AMPL or GAMS modeling session.
Guide to Installing and Using the Kestrel AMPL Client
Installing AMPL and Kestrel
To use Kestrel with AMPL, you need to have the AMPL interactive
environment installed on your local computer. If you do not
have the AMPL environment installed, you can download a test version
that accepts problems with up to 300 variables and 300 constraints; see the
AMPL website for instructions.
There are two versions of Kestrel for AMPL, one for Linux/Mac OS X and one for Windows. Download the correct version for your system and unzip the file. As of March 28, 2017, both versions have been updated to work with HTTPS.
- Linux/Mac OS X: Python must be installed.
- Download kestrel.tar.gz.
- Unzip kestrel.tar.gz into a directory in the path. We recommend the same directory as the AMPL binary.
- Download kestrel.zip.
- Unzip kestrel.zip into same directory as the AMPL executable.
- Develop your model within the AMPL environment.
- Set the solver options.
option solver kestrel; as the solver.
- Specify the remote solver name, e.g., CPLEX:
- Specify the URL of the NEOS Server:
- Note: If you do not know what solvers are available via Kestrel, omit the solver name and submit the job. The list of enabled solvers
will be returned.
- Submit the job to the NEOS Server by typing
- If you are disconnected from the Kestrel server during your
job execution, type
If your job is still in progress, your
AMPL session will resume waiting. Otherwise, your results will be
Note: On Windows, you will get an error message that the client requires python24.dll to
run. Please ignore this message, since the client can execute without this library.
Guide to Installing and Using the Kestrel GAMS Client
Installing GAMS and Kestrel
To use Kestrel with GAMS, you need to have GAMS 24.8 or newer installed on
your local computer. Since GAMS 23.7, the Kestrel GAMS client has been included in the standard GAMS
distribution for all supported architectures, so you only need Python version 2.5 or above to be
installed on your machine.
Using Kestrel with GAMS
- Develop your model within the GAMS environment.
- Create an options file called
- Specify the name of the solver and the URL for the NEOS Server.
- Include any solver specific options.
- Note: If you do not know what solvers are available via Kestrel,
omit the solver name and submit the job. The list of enabled solvers will be
- To run your GAMS job on the command line, set the solver to
kestrel and set
optfile=1. The Kestrel solver
accepts all model types.
- If you are disconnected from the Kestrel server, you can retrieve the results for your job from the NEOS Server admin page