Re: [ckrm-tech] [PATCH] BC: resource beancounters (v4) (added user memory)

[Shailabh Nagar <nagar@watson.ibm.com>]

Rohit Seth wrote:

>> Memory resources, by their very nature, will be tougher to account when a
>> single database/app server services multiple clients and we can essentially
>> give up on that (taking the approach that only limited recharging can ever
>> be achieved). 
> 
> What exactly you mean by limited recharging?  
> 

Memory allocated (and hence charged) by a task belonging to one container
being (re)charged to another container to which task moves. Can be done but at
too high a cost so not worth it most of the time.


> As said earlier, if there is big shared segment on a server then that
> can be charged to any single container.  And in this case moving a task
> to different container may not fetch anything useful from memory
> accounting pov.
> 
>> But cpu atleast is easy to charge correctly and since that will
>> also indirectly influence the requests for memory & I/O, its useful to allow
>> middleware to change the accounting base for a thread/task.
>>
> 
> That is not true.   It depends on IO size, memory foot print etc. etc.
> You can move a task to different container, but it will not be cheap.
> 
For cpu time & I/O bandwidth I disagree. Accounting to a multiplicity of
containers/BC over time shouldn't be costly.

Anyway, lets see how the implementation evolves.

> -rohit