[p4] P4P Network Performance

[Chad Catlett]

Hello all,

Recently our main P4D server has been under increasing IO load. As a
temporary measure I've setup a local P4P server, during testing I
noticed we can't seem to get more than 10MB/sec throughput from the
server, even for files that are in the P4P cache. I've tried various
hardware configurations to rule out it wasn't the initial server's
hardware. Out of the three servers I tested, each peak at around
10MB/sec.  If I transfer files from the P4P cache on these servers via
FTP or CIFS, then I get nearly 100MB/sec to the same client machines.

To test I fetch a file to force it into the cache, I've verified it is
there by going through the file system and checked. Then I make sure it
is not in the client's workspace, then fetch the file. Every time, its
10MB/sec. if I remove the file, and sync that file again I get the same
speed. I've verified via -Zproxyverbose that it is coming from the
proxy's cache.

If anyone could offer advice on speeding it up I'd appreciate it
greatly.

BTW, here are the specs on the various machines I tested with

Client #1:
	4GB of memory
	2 DualCore AMD @ 2.8Ghz
	2 x 250GB sata drives in a RAID 0 array
	Running Windows Vista.
	Networking is a single gigabit link to the network.

Client #2
	2 Xeons @ 2.8GHz 
	4GB of memory
	2 x 146GB scsi drives in a RAID 1 array
	Running Ubuntu 6.06LTS
	Networking is a single gigabit link to the network.

Server #1:
	2 Xeons @ 2.8GHz 
	4GB of memory
	2 x 146GB scsi drives in a RAID 1 array
	Running Windows 2003 R2 x64
	Networking is a single gigabit link to the network.

Server #2:
	2 Xeons @ 2.8GHz 
	4GB of memory
	2 x 146GB scsi drives in a RAID 0 stripe array
	Running Windows 2003 R2 x64
	Networking is a single gigabit link to the network.

Server #3:
	2 x AMD Opteron 250 @ 2.3GHz
	2GB of memory
	4 x 250 sat drives in a RAID 0 strip array.
	Running Ubuntu 6.06LTS
	Networking is 3 x 1gbit links for user facing traffic
		one gbit link for talking to main P4D server.

All these were connected to our core network switch, which is a Cisco
Catalyst 4510R. 



Thanks for any advice that can be offered.

Chad