On Sat, 8 Oct 2011, Brian Bockelman wrote:
>
> On Oct 7, 2011, at 3:37 PM, Andrew Hanushevsky wrote:
>> What does that mean? You want a single entry? That's not always possible since readv allows you to read from multiple files using a single vector.
> Interesting! Is there an example use of this interface?
To example uses but it was put in with anticipation of some very clever
person capitalizing on this feature.
> Well there's a middle-ground use case here: being able to monitor
> activity for each open connection.
>
> In our experience, without the very detailed I/O monitoring, we:
> 1) Don't get any monitoring for a client that crashes (disconnects without a close).
That information can be put in the summary record, if need be. I say need
be because it's a relatively rare event (yes, it does happen in spurts).
> 2) Don't get monitoring while a client is running. Example: it's been
> 5 hours since a job has started; is this because it is getting 1 byte /
> second, or because the job takes 5 hours and 1 minute?
True, there is no other way of capturing this information. Another case
where some more client input would make things more effecient.
> So, we find it extremely useful without doing the data access patterns
> use case. Either way we get the information - unrolling the vector to
> include all the data, or getting a summary - we'll be happy.
OK, I will take this into consideration when comming up with a fix.
Andy
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