[Lustre-discuss] RPCs in flight

[Lee, Brett]

Hi Patrick,

This setting reflects how much network IO, in the form of unacknowledged RPCs, a client can have sent (in flight) at any one time.

A setting of 8 would mean that the client can have 8 RPC's out to each OST.

It affects performance in that a client, which might otherwise be waiting for RPC replies, can keep sending and not block - helpful for large asynchronous IO.

Of course, if too many clients are sending too much and overwhelm the storage servers, then performance could be negatively impacted as well.

--
Brett Lee
Sr. Systems Engineer
Intel High Performance Data Division

From: lustre-discuss-bounces at lists.lustre.org [mailto:lustre-discuss-bounces at lists.lustre.org] On Behalf Of Chan Ching Yu, Patrick
Sent: Thursday, June 27, 2013 4:57 PM
To: lustre-discuss at lists.lustre.org
Subject: [Lustre-discuss] RPCs in flight

Dear all,

Just raise a probably stupid question. I always see the word "RPCs in flight".

What does it mean? How does it affect the performance?

Thanks very much.


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