[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: [tor-bugs] #23817 [Core Tor/Tor]: Tor re-tries directory mirrors that it knows are missing microdescriptors
#23817: Tor re-tries directory mirrors that it knows are missing microdescriptors
----------------------------------------+----------------------------------
Reporter: teor | Owner: (none)
Type: defect | Status: new
Priority: Medium | Milestone: Tor:
| 0.3.3.x-final
Component: Core Tor/Tor | Version:
Severity: Normal | Resolution:
Keywords: tor-guard, tor-hs, prop224 | Actual Points:
Parent ID: #21969 | Points:
Reviewer: | Sponsor:
----------------------------------------+----------------------------------
Comment (by asn):
Here is a draft of a suggested technical solution here which involves a
cache tracking failed md downloads:
1) Introduce an `md_failure_cache` cache which tracks failed or missing
mds downloads per relays. That is a cache with entries as follows: "We
failed to fetch md <hash> from relays X, Y, Z".
engineering XXX: how to figure out missing mds from received batches
2) When we want to fetch a batch of mds from relay X, check
`md_failure_cache` to see if any of the batched mds is included in the
cache for relay X. if that's the case, add relay X to the excluded list of
nodes for dirservers, so that our directory subsystems skips relay X and
moves to the next one in line.
engineering XXX: is there an exclude list for dirserver
downloads?
3) When we succeed in fetching an md, remove its entries from the cache
(so that we retry in the future from relay X which is probably our top
primary guard).
4) Finally, to address #23863, when we detect that we are missing mds from
our primary guards, order an immediate download of those missing mds, so
that the previous steps get done.
--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/23817#comment:4>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online
_______________________________________________
tor-bugs mailing list
tor-bugs@xxxxxxxxxxxxxxxxxxxx
https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-bugs