Opened 2 years ago

Last modified 2 years ago

#24022 closed defect

Make clients avoid retrying slow exits when they time out — at Version 2

Reported by: teor Owned by:
Priority: Medium Milestone: Tor: 0.3.3.x-final
Component: Core Tor/Tor Version:
Severity: Normal Keywords: tbb-performance, tbb-usability, performance, tbb-needs
Cc: gk, brade, mcs, arthuredelstein Actual Points:
Parent ID: #21394 Points:
Reviewer: Sponsor:

Description (last modified by teor)

In #21394, we discovered that Tor clients sometimes retry the same exit, even when it is timing out.
Can we retry fewer times, but still have an acceptable risk of clients encountering a bad exit?

experience a lot of exit timeouts when trying to connect to a website via DNS.

Child Tickets

Change History (2)

comment:1 in reply to:  description Changed 2 years ago by arthuredelstein

Replying to teor:

In #21394, we discovered that Tor clients sometimes retry the same exit, even when it is timing out.
Can we retry fewer times, but still have an acceptable risk of clients encountering a bad exit?

Is that true? I hadn't concluded that from the data, but I'm not familiar with the code. Does it return to the same exit more than would be expected by a random exit selection?

comment:2 Changed 2 years ago by teor

Description: modified (diff)
Summary: Make clients avoid retrying the same exit when it times outMake clients avoid retrying slow exits when they time out

Oh, I see. Those were attempts to random exits that timed out before completing.
Maybe we could fix that at the client level by keeping an exit failure cache?
But the client would still need to experience some timeouts before it could skip failed exits.

Note: See TracTickets for help on using tickets.