5.1 Cache User Credentials

Moab Adaptive HPC

5.1 Cache User Credentials

Before you can submit jobs, your credentials must be cached on the HPC 2008 R2 head node, which allows the MSMHPC service to authenticate when it submits the job to HPC 2008 R2. Credential caching only needs to be done once for each user. Once cached, you can submit jobs normally with the msub command. To cache user credentials, use either MSMHPC Manager, the MSMHPCCacheCredentialsCLI / MSMHPCCacheCredentialsGUI application, or the user.cache.pl script that was provided with the MSMHPC Perl scripts.

If the credentials are not cached on submission or start, the job will be deferred and have a message attached to it in Moab indicating that the credentials are not cached and which user attempted to start the job.

The ./user.cache.pl script is the recommended method. It may have one of the following three syntaxes:

./user.cache.pl - prompts for username and password twice.
./user.cache.pl<username> - prompts for password twice.
./user.cache.pl<username><password> - no prompt given.

Items for Special Consideration

Configure the env.hpc file (shipped with the MSMHPC tools) to reflect your configuration. Then source, or load, the file when you wish to cache user credentials:
```
> . env.hpc
> ./user.cache.pl
```
These credentials are sent in plain text over the network.
The domain configured in moab.cfg is automatically appended to the username.
If a job will not start and gets stuck in the "Blocked" queue, run the checkjob command to diagnose the issue:
```
> checkjob -v <jobid>
```
Note whether the following message appears as a "block reason": "The supplied username (<username>) was not cached." If you see this message, recache your credentials (because they were not cached, have expired, or the user password has changed).
Moab cannot process jobs submitted directly from Windows if user credentials are not cached through MSMHPC / Moab. If Moab detects this, Windows jobs are canceled with the following reason:
Moab won't be able to process this job until you cache the credentials for user <user>. Please refer to the documentation for more information.
Administrators can check the Activation Filter's log files in the MSMHPC Manager for the reason jobs are canceled.

To use the MSMHPCCacheCredentialsCLI and MSMHPCCacheCredentialsGUI applications instead of your script to cache your credentials, copy both the application you want and the MSMHPCConnections.dll file to the

msmhpc_cache_credentials_gui

The public key refers to the key set up in Installing the MSMHPC Services. Host refers to the host name or IP address of the machine running the MSMHPC service.

Note Both of the clients (CLI and GUI) must reach the Windows head node's port 5343.