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update SSK latency/creation-time graph links 

[Imported from Trac: page Performance, version 26]
warner 2008-01-30 19:04:18 +00:00
parent c01dae2464
commit 50b32e86ce
1 changed files with 18 additions and 3 deletions
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21
Performance.md

@ -61,9 +61,6 @@ The munin
[/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_delay.html delay graph] and [/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_delay.html delay graph] and
[/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_rate.html rate graph] show these Ax+B numbers for a node in colo and a node behind a DSL line. [/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_rate.html rate graph] show these Ax+B numbers for a node in colo and a node behind a DSL line.
The [/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_delay_SSK.html mutable-file delay graph] shows the "B" per-file latency number
for mutable (aka "SSK") files. In the 0.7.0 release, this is dominated by the RSA keypair generation necessary to create each new mutable file.
The The
[/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_delay_rtt.html delay*RTT graph] shows this per-file delay as a multiple of the average round-trip [/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_delay_rtt.html delay*RTT graph] shows this per-file delay as a multiple of the average round-trip
time between the client node and the testnet. Much of the work done to upload time between the client node and the testnet. Much of the work done to upload
@ -71,6 +68,24 @@ a file involves waiting for message to make a round-trip, so expressing the
per-file delay in units of RTT helps to compare the observed performance per-file delay in units of RTT helps to compare the observed performance
against the predicted value. against the predicted value.
### Mutable Files
Tahoe's mutable files (sometimes known as "SSK" files) are encoded
differently than the immutable ones (aka "CHK" files). Creating these mutable
file slots currently (in release 0.7.0) requires an RSA keypair generation.
[This graph](http://allmydata.org/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_SSK_creation.html)
tracks the amount of time it takes to perform
this step.
There is also per-file overhead for upload and download, just like with CHK
files, mostly involving the queries to find out which servers are holding
which versions of the file. The
[/tahoe-figleaf-graph/hanford.allmydata.com-tahoe_speedstats_delay_SSK.html mutable-file delay graph]
shows this "B" per-file latency value.
The "A" transfer rate for SSK files is also tracked. TODO: add a link to the
graph.
### Roundtrips ### Roundtrips
The 0.5.1 release requires about 9 roundtrips for each share it uploads. The The 0.5.1 release requires about 9 roundtrips for each share it uploads. The