diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/TODO | 2 | ||||
| -rw-r--r-- | doc/spec/dir-spec.txt | 25 |
2 files changed, 23 insertions, 4 deletions
@@ -306,7 +306,7 @@ Documentation for Tor 0.2.0.x: . 111: Prioritize local traffic over relayed. R - Merge into tor-spec.txt. - 113: mark as closed close. -N - document the "3/4 and 7/8" business in the clients fetching consensus + o document the "3/4 and 7/8" business in the clients fetching consensus documents timeline. R - then document the bridge user download timeline. - HOWTO for DNSPort. See tup's wiki page. diff --git a/doc/spec/dir-spec.txt b/doc/spec/dir-spec.txt index 3419abb3af..d2851f6036 100644 --- a/doc/spec/dir-spec.txt +++ b/doc/spec/dir-spec.txt @@ -1336,9 +1336,15 @@ $Id$ - The cache has no consensus document. - The cache's consensus document is no longer valid. Otherwise, the cache downloads a new consensus document at a randomly - chosen time after its current consensus stops being fresh. (This time is - chosen at random to avoid swarming the authorities at the start of each - period.) + chosen time in the first half-interval after its current consensus + stops being fresh. (This time is chosen at random to avoid swarming + the authorities at the start of each period. The interval size is + inferred from the difference between the valid-after time and the + fresh-until time on the consensus.) + + [For example, if a cache has a consensus that became valid at 1:00, + and is fresh until 2:00, that cache will fetch a new consensus at + a random time between 2:00 and 2:30.] 4.4. Downloading and storing router descriptors (authorities and caches) @@ -1515,6 +1521,19 @@ $Id$ from an authority, they should not need to go to the authority directly again.) + To avoid swarming the caches whenever a consensus expires, the + clients download new consensuses at a randomly chosen time after the + caches are expected to have a fresh consensus, but before their + consensus will expire. (This time is chosen uniformly at random from + the interval between the time 3/4 into the first interval after the + consensus is no longer fresh, and 7/8 of the time remaining after + that before the consensus is invalid.) + + [For example, if a cache has a consensus that became valid at 1:00, + and is fresh until 2:00, and expires at 4:00, that cache will fetch + a new consensus at a random time between 2:45 and 3:50, since 3/4 + of the one-hour interval is 45 minutes, and 7/8 of the remaining 75 + minutes is 65 minutes.] 5.2. Downloading and storing router descriptors |