[p4] Performance of remote perforce depots and proxies

[steve@vance.com]

No problem, Craig. Tim is good and would be awake now. I just happen to be
near your time zone right now.

Don't forget to also work with your ISP to tune the packet parameters
there. I wouldn't be as concerned with your client parameters except to the
extent that they match the parameters on your server. Your main issue will
be the traffic between the proxy and the remote server.

As for the compress flags, I don't see how that would help much. The
communication between the proxy and the server is compressed by default. I
assume you haven't turned that off. Since your communication with the proxy
is over a local network and compression of metadata rarely is worth the
CPU, I don't see the benefit, but Tim usually has good reasons for his
recommendations, so I may be missing something.

The upcoming of caching local submits still won't release the client before
the submit is finished. It will just prevent having to make another request
for the file before it is brought back. It's not clear to me how it will
behave if you have RCS keywords turned on, since that requires a client
file refresh anyway. The submittor will probably incur the penalty.

The last release of the year is usually squeezed in right around Dec 31. :)
But since they have it in beta right now, I would hope for sooner.

Steve

Original Message:
-----------------
From: Craig James Craig.James at thq.com
Date: 	Fri, 2 Nov 2007 13:24:22 +1000
To: steve at vance.com, perforce-user at perforce.com
Subject: RE: [p4] Performance of remote perforce depots and proxies


Thanks for the comments Steve,

Perforce local support also came back to be very quickly (thanks Tim)
and had similar advice to offer.

I'm going to play with "DefaultSendWindow" in the registry
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Afd\Parameters\ on
server and client - based on advice here:
http://www-didc.lbl.gov/TCP-tuning/

	Buffer size = 2 * bandwidth * delay 

Which for us is:

	2 * 10Mbit * 0.250 / 8 = 625000 bytes

There was also the suggestion we turn on the compress flag in each
clientspec (off by default).


Tim also noted that the current proxy does not cache local submits to
remote servers but that this is coming in 2007.3 (currently in beta).

We aren't going to swap to this yet (2007.3 final release possibly early
next year), so will likely have submits coordinated on a single machine
that submits all changes overnight.


Cj



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