From 50b32e86ce23dafadda110646e7a87b248db2390 Mon Sep 17 00:00:00 2001
From: warner <>
Date: Wed, 30 Jan 2008 19:04:18 +0000
Subject: [PATCH] update SSK latency/creation-time graph links

[Imported from Trac: page Performance, version 26]
---
 Performance.md | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/Performance.md b/Performance.md
index 5b553cb..c0bddba 100644
--- a/Performance.md
+++ b/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_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 
 [/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
@@ -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
 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
 
 The 0.5.1 release requires about 9 roundtrips for each share it uploads. The