Add a TIMEOUT_RATE keyword to buildtimeout event. (835ab531) · Commits · The Tor Project / Core / Tor

doc/spec/control-spec.txt

+2 −1

Original line number	Diff line number	Diff line
		@@ -1670,13 +1670,14 @@
		The syntax is:
		"650" SP "BUILDTIMEOUT_SET" SP Type SP "TOTAL_TIMES=" Total SP
		"TIMEOUT_MS=" Timeout SP "XM=" Xm SP "ALPHA=" Alpha SP
		"CUTOFF_QUANTILE=" Quantile CRLF
		"CUTOFF_QUANTILE=" Quantile SP "TIMEOUT_RATE=" Rate CRLF
		Type = "COMPUTED" / "RESET" / "SUSPENDED" / "DISCARD" / "RESUME"
		Total = Integer count of timeouts stored
		Timeout = Integer timeout in milliseconds
		Xm = Estimated integer Pareto parameter Xm in milliseconds
		Alpha = Estimated floating point Paredo paremter alpha
		Quantile = Floating point CDF quantile cutoff point for this timeout
		Rate = Floating point ratio of circuits that timeout

		A new circuit build timeout time has been set. If Type is "COMPUTED",
		Tor has computed the value based on historical data. If Type is "RESET",

src/or/circuitbuild.c

+33 −18

Original line number	Diff line number	Diff line
		@@ -306,8 +306,7 @@ circuit_build_times_add_time(circuit_build_times_t *cbt, build_time_t time)
		return -1;
		}

		// XXX: Probably want to demote this to debug for the release.
		log_info(LD_CIRC, "Adding circuit build time %u", time);
		log_debug(LD_CIRC, "Adding circuit build time %u", time);

		cbt->circuit_build_times[cbt->build_times_idx] = time;
		cbt->build_times_idx = (cbt->build_times_idx + 1) % CBT_NCIRCUITS_TO_OBSERVE;
		@@ -733,9 +732,6 @@ void
		circuit_build_times_add_timeout_worker(circuit_build_times_t *cbt,
		double quantile_cutoff)
		{
		// XXX: This may be failing when the number of samples is small?
		// Keep getting values for the largest timeout bucket over and over
		// again... Probably because alpha is very very large in that case..
		build_time_t gentime = circuit_build_times_generate_sample(cbt,
		quantile_cutoff, CBT_MAX_SYNTHETIC_QUANTILE);

		@@ -988,6 +984,22 @@ circuit_build_times_network_check_changed(circuit_build_times_t *cbt)
		return 1;
		}

		/**
		* Count the number of timeouts in a set of cbt data.
		*/
		double
		circuit_build_times_timeout_rate(const circuit_build_times_t *cbt)
		{
		int i=0,timeouts=0;
		for (i = 0; i < CBT_NCIRCUITS_TO_OBSERVE; i++) {
		if (cbt->circuit_build_times[i] >= cbt->timeout_ms) {
		timeouts++;
		}
		}

		return ((double)timeouts)/cbt->total_build_times;
		}

		/**
		* Store a timeout as a synthetic value.
		*
		@@ -1033,7 +1045,8 @@ static int
		circuit_build_times_filter_timeouts(circuit_build_times_t *cbt)
		{
		int num_filtered=0, i=0;
		build_time_t max_timeout;
		double timeout_rate = 0;
		build_time_t max_timeout = 0;

		/* If we replace high timeouts when the curve is really steep
		* (alpha is above ~1.5), we can end up with a lot of timeouts clustered
		@@ -1045,6 +1058,7 @@ circuit_build_times_filter_timeouts(circuit_build_times_t *cbt)
		return 0;
		}

		timeout_rate = circuit_build_times_timeout_rate(cbt);
		max_timeout = tor_lround(circuit_build_times_calculate_timeout(cbt,
		CBT_MAX_SYNTHETIC_QUANTILE));

		@@ -1058,11 +1072,17 @@ circuit_build_times_filter_timeouts(circuit_build_times_t *cbt)
		CBT_MAX_SYNTHETIC_QUANTILE),
		CBT_BUILD_TIME_MAX);

		log_info(LD_CIRC, "Replaced timeout %d with %d", replaced,
		log_debug(LD_CIRC, "Replaced timeout %d with %d", replaced,
		cbt->circuit_build_times[i]);
		}
		}

		log_info(LD_CIRC,
		"We had %d timeouts out of %d build times, "
		"and filtered %d above the max of %u",
		(int)(cbt->total_build_times*timeout_rate),
		cbt->total_build_times, num_filtered, max_timeout);

		return num_filtered;
		}

		@@ -1094,13 +1114,12 @@ void
		circuit_build_times_set_timeout(circuit_build_times_t *cbt)
		{
		int filtered=0,timeouts=0,i=0;
		double timeout_rate;

		if (!circuit_build_times_set_timeout_worker(cbt))
		return;

		if ((filtered = circuit_build_times_filter_timeouts(cbt)) > 0) {
		log_info(LD_CIRC, "Filtered out %d timeouts. Recomputing timeout.",
		filtered);
		circuit_build_times_set_timeout_worker(cbt);
		}

		@@ -1112,11 +1131,7 @@ circuit_build_times_set_timeout(circuit_build_times_t *cbt)

		control_event_buildtimeout_set(cbt, BUILDTIMEOUT_SET_EVENT_COMPUTED);

		for (i = 0; i < CBT_NCIRCUITS_TO_OBSERVE; i++) {
		if (cbt->circuit_build_times[i] >= cbt->timeout_ms) {
		timeouts++;
		}
		}
		timeout_rate = circuit_build_times_timeout_rate(cbt);

		log_info(LD_CIRC,
		"Set circuit build timeout to %lds (%lfms, Xm: %d, a: %lf, r: "

src/or/control.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -3529,10 +3529,12 @@ control_event_buildtimeout_set(const circuit_build_times_t *cbt,

		send_control_event(EVENT_BUILDTIMEOUT_SET, ALL_FORMATS,
		"650 BUILDTIMEOUT_SET %s TOTAL_TIMES=%lu "
		"TIMEOUT_MS=%lu XM=%lu ALPHA=%lf CUTOFF_QUANTILE=%lf\r\n",
		"TIMEOUT_MS=%lu XM=%lu ALPHA=%lf CUTOFF_QUANTILE=%lf "
		"TIMEOUT_RATE=%lf\r\n",
		type_string, (unsigned long)cbt->total_build_times,
		(unsigned long)cbt->timeout_ms,
		(unsigned long)cbt->Xm, cbt->alpha, qnt);
		(unsigned long)cbt->Xm, cbt->alpha, qnt,
		circuit_build_times_timeout_rate(cbt));

		return 0;
		}

src/or/or.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -3152,6 +3152,7 @@ int circuit_build_times_needs_circuits_now(circuit_build_times_t *cbt);
		void circuit_build_times_init(circuit_build_times_t *cbt);
		void circuit_build_times_new_consensus_params(circuit_build_times_t *cbt,
		networkstatus_t *ns);
		double circuit_build_times_timeout_rate(const circuit_build_times_t *cbt);

		#ifdef CIRCUIT_PRIVATE
		double circuit_build_times_calculate_timeout(circuit_build_times_t *cbt,