[tahoe-lafs-trac-stream] [tahoe-lafs] #1545: add readv() API to immutable-share storage-server protocol, use in downloader
tahoe-lafs
trac at tahoe-lafs.org
Mon Sep 26 23:53:43 PDT 2011
#1545: add readv() API to immutable-share storage-server protocol, use in
downloader
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Reporter: warner | Owner:
Type: enhancement | Status: new
Priority: major | Milestone: undecided
Component: code-storage | Version: 1.9.0a2
Resolution: | Keywords: performance
Launchpad Bug: |
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Comment (by warner):
early results suggest that doing this would speed up high-k immutable
downloads by about 24%. For example, k=54 with trunk takes roughly 414s to
download a 100MB file (6 servers, 3 hosts, LAN connections). When basic
readv() is used, this drops to 317s. For small k (like the default k=3),
the effect is less clear, however there still seems to be a significant
improvement (k=3 trunk 100MB takes maybe 38s, with-readv takes 32s).
The effect is roughly halfway between unmodified trunk CHK and trunk MDMF
(which prefetches the whole block_hash_tree and doesn't even have a
crypttext_hash_tree).
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Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/1545#comment:1>
tahoe-lafs <http://tahoe-lafs.org>
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