updatinator benchmarking (Was: rsync benchmarking)

[Alexander Larsson]

On Tue, 2007-07-10 at 16:21 +0200, Alexander Larsson wrote:

> > 464-to-465:
> > Full contents of tree: 429,302,610 bytes
> > rsync --whole-file: sent 32,034 bytes; received 13,153,813 bytes.
> > Standard rsync: sent 96,720 bytes; received 10,047,524 bytes. 9.0s
> > user, 64.9s real
> > Rsync-with-manifest: sent 79,192 bytes; received 9,139,515 bytes. 4.3
> > user, 11.5s real.
> 
> Updatinator:
> sent 596,681 bytes
> recieved 7,545,281 bytes

So, i took a deeper look into what all the sent bytes are from by using
a network sniffer, transfering from a local http server. Using wireshark
I got slightly different (likely more accurate) bytecounts for just the
download.

sent: 421,134 bytes
received: 7,974,280 bytes

About the same download size, but slightly different sent count.
Probably because I only counted the actual transfer and not other things
happening on the machine. However, its still pretty large.

So, what kind of data are we sending?

We're doing 357 http GET requests, at about an average request packet
size of 245.613 bytes, totalling 87,684 bytes.

The rest of the data sent is tcp control flow packets (ACK, SYN, FIN
etc), totalling at 333,450 bytes. We send so many of these packets (66
byte each) because we're recieving a lot of data to ack.

Actually the http request size above includes the packet headers etc, so
the numer of bytes sent at the application level (the tcp payload) is
only 64,122 bytes. I believe the numbers above for rsync is just the tcp
payload data, so updatinator is actually at about the same size for sent
bytes.