[tahoe-dev] Fwd: starting to use volunteergrid1 -- survivability and performance measurement

[Zooko O'Whielacronx]

Folks:

I wrote this to the volunteergrid1 mailing list. I edited out the
nicknames of the servers below before forwarding it to tahoe-dev.

Regards,

Zooko


---------- Forwarded message ----------
From: Zooko O'Whielacronx <zooko at zooko.com>
Date: Fri, May 27, 2011 at 5:04 PM
Subject: starting to use volunteergrid1 -- survivability and
performance measurement
To: volunteergrid-l at tahoe-lafs.org


Folks:

I just created a directory to be my new root directory for stuff I
store on volunteergrid1. Then I immediately checked it:

Share ID		Nickname						Node ID
--------		--------						-------
seq1-7ahx-sh0	xxxxxxxxxxx					m2sbabta5mc22ijtfkcidmpwbuxbp3bf
seq1-7ahx-sh1	xxxxxxxxxxxx					bwxr6cbkutq2s5slg7dhh5ukejn6567i
seq1-7ahx-sh2	xxxxx						63hhqm64talajpn5zu343ui3bhi4tfcc
seq1-7ahx-sh3	xxxxxxxxxxxxxxxxxxxxxxxxxxxxx	xlnzwmko5inqjs4krxk35yj2sqjtb6ma
seq1-7ahx-sh4	xxxxxxxxxxxxxxx				x2l47knnwwvfxonturznfh3n5hh7g7a2
seq1-7ahx-sh5	xxxxxxxxxxxxxxxxxxxxxxxx		iutxbkwuy5ekowafh7r4nrxl3v446irx
seq1-7ahx-sh6	xxxxxxxxxxxx					hpdlcilo7cjag7c4ffzehavh2wdv2zrp
seq1-7ahx-sh7	xxxxxxxxxxx					ysxpoywqf37dpaxxuonoqc3bod24ic6w
seq1-7ahx-sh8	xxxxxxxxxxxxxxx				gtnnoahwi5ukb4ztjs3un7mh7joopb33
seq1-7ahx-sh9	xxxxxxxxxxx					m2sbabta5mc22ijtfkcidmpwbuxbp3bf

Very nice! Thank you all. At least for small objects like an empty
directory, volunteergrid1 offers extremely high survivability!

How about the performance? Let's see...

   Total: 678ms (0Bps)
       Setup: 176us
       Encrypting: 25us (0Bps)
       Encoding: 45us (0Bps)
       Packing Shares: 14ms (0Bps)
           RSA Signature: 13ms
       Pushing: 664ms (0Bps)
   Per-Server Response Times:
       [bwxr6cbk]: 326ms
       [gtnnoahw]: 648ms
       [hpdlcilo]: 395ms
       [iutxbkwu]: 181ms
       [m2sbabta]: 470ms
       [xlnzwmko]: 663ms
       [x2l47knn]: 651ms
       [ysxpoywq]: 170ms
       [63hhqm64]: 341ms

Not bad!

I wonder why I don't see a 1-second or 2-second measurement in there
for generating the new RSA keypair. Maybe the "key generator" feature
is turned on by default and it has pre-generated and cached one?

And here are the timings to fetch the directory:

   Total: 1.8ms (0Bps)
       Fetching: 1.6ms (0Bps)
       Decoding: 84us (0Bps)
       Decrypting: 36us (0Bps)

Too bad it doesn't say which three servers it used to fetch, but in
any case the performance was A-okay! :-)

And here are the timings to check the directory (producing the checker
result that I posted above):

   Total: 227ms
       Initial Queries: 6.3ms
       Cumulative Verify: 1.4ms
   Per-Server Response Times:
       [bwxr6cbk]: 215ms
       [gtnnoahw]: 186ms
       [hpdlcilo]: 226ms
       [iutxbkwu]: 128ms
       [m2sbabta]: 130ms
       [xlnzwmko]: 216ms
       [x2l47knn]: 221ms
       [ysxpoywq]: 103ms
       [63hhqm64]: 130ms