Opened 9 years ago

Closed 7 years ago

Last modified 7 years ago

#2104 closed enhancement (implemented)

Turn on sub-second rate limiting granularity

Reported by: arma Owned by: nickm
Priority: Medium Milestone: Tor: 0.2.3.x-final
Component: Core Tor/Tor Version:
Severity: Keywords: tor-relay
Cc: Actual Points:
Parent ID: Points:
Reviewer: Sponsor:

Description

The bufferevents patches are now in Tor (but not enabled by default).

Did that include the "refill the token buckets more than once a second so we don't have big traffic bumps" feature that we've been waiting for?

If so, we should talk about what parameters are good to use.

If not, what remains?

Child Tickets

Change History (5)

comment:1 Changed 9 years ago by nickm

It's there, and it gets set when bufferevents are enabled. See the TOR_LIBEVENT_TICKS_PER_SECOND define in compat_libevent.h.

comment:2 Changed 9 years ago by nickm

Milestone: Tor: 0.2.3.x-final

If so, we should talk about what parameters are good to use.

So right now, TOR_LIBEVENT_TICKS_PER_SECOND is 3. If we make that too high, then refilling and trickling out data can conceivably eat too much CPU. If we make it too low, then we get spiky traffic. I think something between 2 and 10 is probably right. How can we tell what the right answer is?

One possible idea is to try different values on a busy rate-limited Tor server. To see if we've got it too high, look for bad performance. To see if we've got it too low, look for ... whatever bad spiky traffic behavior we're used to disliking.

comment:3 Changed 7 years ago by nickm

Resolution: implemented
Status: newclosed

So, this is implemented now, and turned on. We're not happy with the tuning, but there's another set of tickets for that. Closing this one.

comment:4 Changed 7 years ago by nickm

Keywords: tor-relay added

comment:5 Changed 7 years ago by nickm

Component: Tor RelayTor
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