[Twg] [Discuss] [Lustre-devel] your opinion about testing

[Roman Grigoryev]

Hi Nathan,

I think it is very interesting possibility but, but from QA/QE logic
there is problem : we are planing to use for test control messages
channel which is under test too. So, we have to have separated lnet test
for prove that lnet is working ok before starting full testing session.

Also we must keep possibility to execute tests (maybe not all) without
this feature, in classic way, f.e. via ssh.

Thanks,
	Roman


On 05/01/2012 02:37 AM, Nathan Rutman wrote:
>>
>>> 3. Remote operations via lctl messages.
>>> The tests frequently fail to work on many clusters due to passwordless ssh requirements.  Instead, remote commands / function calls should be sent to other Lustre nodes via a new LNET command, similar to 'lctl ping', that allows arbitrary data to be sent.  A "testing upcall" procedure would be registered on the remote node and would receive the messages.  Obviously this could be a more broadly useful mechanism.  Due to security issues some sites may chose not to register an upcall. A response mechanism is also required.
>>
>> It is not immediately clear how this fixes anything.  Such a facility 
>> built into lnet needs to have exactly the same configuration issues as 
>> ssh, munge, or whatever.  If it DOESN'T have the same issues, then it 
>> sounds like it would be a very serious security risk.
> What it fixes is the ease of testing, by not requiring a separate communication path outside of LNET.  No router problems, no ssh'isms; if your client can talk to your servers, you're good to go.  
> Obviously it doesn't resolve any security issues, and may introduce new ones.
> 
>>
>> Such a feature needs to at least be off by default and only enabled by a 
>> human deciding that such a remote-access feature is acceptable.
> Agreed. Hopefully it might be easier to qualify a particular upcall program as "safe", rather than allowing arbitrary code execution as ssh does, but that's not the intent here.  
> The goal is to fix the testing, and I think this is one useful component of that.
> _______________________________________________