[Lustre-devel] using LST for performance testing

[Nic Henke <nic@cray.com>]

David Dillow wrote:
> On Tue, 2009-09-29 at 11:51 -0500, Nic Henke wrote:
>   
>> I'm wondering if we couldn't add a new 'batch_stat' command. The idea is 
>> that the client code will fill in the start/stop times for each test and 
>> then after the test is done, 'batch_stat' would collect this data. The 
>> collection would still be passive and a new command should minimize the 
>> protocol changes. The per-test data would allow us to get accurate perf 
>> numbers and also provide some data into how parallel the tests were, if 
>> there are any unfairness issues, etc.
>>     
>
> Along these lines, it would be nice if we could specify a run time for
> each test rather than an amount of data to be transferred -- it makes it
> easier to get aggregate bandwidth numbers, and often shows imbalances
> nicely -- the node getting starved is the one that transfers less data.
>   
> It may also make sense to add a 'delay' parameter that causes each test
> to wait a specified amount of time from the 'go' signal. This allows the
> signal to propagate without running into congestion from the test,
> helping to cause all of the clients to start the test closer to
> simultaneously.
>   

Interesting - can you elaborate, perhaps in the form of a patch  ? :-) I 
like both ideas, but not signing up to code them just yet.

Nic