A p4proxy is used to provide remote access to a Perforce server without replicating the full database. It acts as a stateless bridge between clients and the main server. The document discusses using a p4proxy with an alternate transport like UDP to improve file transfer speeds over high latency networks, as TCP performance was insufficient. It implemented a commercial UDP solution from Aspera that increased transfer rates to 1 GB in a couple minutes, allowing for near-real time mirroring between sites. The stateless nature of the p4proxy allows for innovative solutions like abandoning TCP in favor of UDP to optimize WAN data transfers.

1. 1
Perforce Proxy with Alternate
Transport
Matt Janulewicz
Perforce Administrator
Lucasfilm Entertainment Company Ltd. Logo area

2. 2
Review: What is a p4proxy?
• Server: db and archives
• Proxy: no db
• Long distance query,
archives nearline
• Stateless

3. 3
Bridging the Gap
We
need
files!
Sure
thing!
Come
get
them!
P4
Sync
We’d
like
those
files,
too!
They’re
already
here!
Nice!

4. 4
Why not a Replica? (2012.2)
• ~6 TB of data, of which we need ~1.5 TB
remotely
• Easier archive management/pruning (stateless)
• This could all change with 2013.1, but archive
transfers will still be a problem

5. 5
The Enemy: Network Latency
P4
ping
latency
nearly
2
seconds

6. 6
The Enemy: Network Latency
Transfer
rate
well
under
.5
MB/s

7. 7
The Enemy: Network Latency
Tweaking
TCP/IP
stack
shows
10x
improvement,
but
sPll
not
enough

8. 8
Solution: Dispense with TCP/IP
• Stateless nature of Proxy lends to alternate
transports
• UDP is lightweight, low overhead
• Little error checking
• No ordering of packets
• No congestion control

9. 9
Bridging the Gap
1
GBps
UDP
will
use
all
of
this,
indiscriminately

10. 10
UDP Implementation
Commercial
implementaPon
from
Aspera.
We
already
owned
point
to
point
product,
added
‘async’
(rsync
drop-­‐in
replacement.)

11. 11
UDP Implementation
• Aspera allows throttling
• Set to 20-25 MB/s
• 1 GB in just a couple minutes
• Can change as need arises
• Rsync drop-in allows near-realtime mirroring
• Other implementations exist, be clever

12. 12
Takeaways
• Proxy statelessness allows cleverness
• Ditch TCP/IP
• On-demand/partial replicas still have large data
transfer needs
• Questions?

13. 13
Contact
Matt Janulewicz
Lucasfilm Entertainment Company Ltd. (a division of Disney)
matt.janulewicz@lucasfilm.com
mattyj@rocketmonkey.net