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

From: Shailabh Nagar
Date: Fri Sep 08 2006 - 17:25:33 EST


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

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