Uhm! why async timers? You'd want to implement a leaky/token bucket per site. Check out...
https://github.com/rigtorp/TokenBucket It's single header file lock free implementation for token bucket and it works very well... On Fri, Jun 21, 2019 at 7:38 PM Weixi Li (BLOOMBERG/ PRINCETON) < wli...@bloomberg.net> wrote: > What a great community! So many good tips in such a short time! > > Especially the atscppai, I would've never noticed it. the async examples > look very promising. > > It looks like the following might be necessary (let me know if I'm wrong): > * A hook to TS_HTTP_SEND_REQUEST_HDR_HOOK > * A map of queues (one queue per rate-limited site) > * A map of async timers (one timer per queue) > > I will study the ATS code more to understand the event and threading model > better. > > Thank you all. > > From: dev@trafficserver.apache.org At: 06/21/19 19:52:44To: > dev@trafficserver.apache.org > Subject: Re: Implementing Rate-limiting in forward proxy mode > > I have implemented rate-limit in my plugin using atscppapi. We are using > ats in > security context for mitigation. If the request matches certain criteria > (ip, > method, host, uri and header values) then we apply rate-limit to that ip. > > Dk. > > > On Jun 21, 2019, at 3:15 PM, Leif Hedstrom <zw...@apache.org> wrote: > > > > > > > >> On Jun 21, 2019, at 16:09, Weixi Li (BLOOMBERG/ PRINCETON) > <wli...@bloomberg.net> wrote: > >> > >> Hi team, > >> > >> We are experimenting with ATS in *forward* proxy mode. Our use-case > requires > a rate-limiting component that enforces rules based on the destination. > >> > >> For example: > >> > >> For all incoming requests targeting "www.cnn.com", we want to limit > the > outgoing rate to be 10 requests per minute; for "www.reddit.com", we want > the > rate to be 20 requests per minute; and so on. If there were more requests > than > the limit specified, the requests must be queued before they could go out. > > > > Seems very straight forward to implement as a plugin. For example the > geo_acl > plugin might be a good start, since it limits access based on source IP. > > > > Would be interesting to hear more about your use case too, it’s always > exciting to hear about different solutions that people use ATS for. Maybe > at > the next ATS summit? :-) > > > > Cheers, > > > > — Leif > >> > >> Is it possible to implement this requirement using a plugin? > >> > >> If not, we wouldn't mind forking the code and modifying whichever parts > that > would be necessary. But which are the potentially relevant components? > >> > >> If any experts could give us some pointers on the design, that would be > really appreciated. > >> > >> Thanks, > >> Weixi > > > > >
