[or-cvs] [tor/master 16/28] Add timeout count state variable.
nickm at torproject.org
nickm at torproject.org
Tue Jun 29 23:07:14 UTC 2010
Author: Mike Perry <mikeperry-git at fscked.org>
Date: Mon, 7 Jun 2010 02:36:43 -0700
Subject: Add timeout count state variable.
Commit: 38770dd6a580e1620f257042b73ea563fc11e862
---
src/or/circuitbuild.c | 117 +++++++++++++++++++++++++------------------------
src/or/config.c | 1 +
src/or/or.h | 3 +-
3 files changed, 63 insertions(+), 58 deletions(-)
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 7ee05d3..f16c8b6 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -470,6 +470,12 @@ circuit_build_times_update_state(circuit_build_times_t *cbt,
*next = NULL;
state->TotalBuildTimes = cbt->total_build_times;
+ state->CircuitBuildTimeoutCount = 0;
+
+ for (i = 0; i < CBT_NCIRCUITS_TO_OBSERVE; i++) {
+ if (cbt->circuit_build_times[i] == CBT_BUILD_TIMEOUT)
+ state->CircuitBuildTimeoutCount++;
+ }
for (i = 0; i < nbins; i++) {
// compress the histogram by skipping the blanks
@@ -522,6 +528,40 @@ circuit_build_times_shuffle_and_store_array(circuit_build_times_t *cbt,
}
/**
+ * Filter old synthetic timeouts that were created before the
+ * right censored new Pareto calculation was deployed.
+ */
+static int
+circuit_build_times_filter_timeouts(circuit_build_times_t *cbt)
+{
+ int num_filtered=0, i=0;
+ double timeout_rate = 0;
+ build_time_t max_timeout = 0;
+
+ timeout_rate = circuit_build_times_timeout_rate(cbt);
+ max_timeout = (build_time_t)cbt->timeout_ms;
+
+ for (i = 0; i < CBT_NCIRCUITS_TO_OBSERVE; i++) {
+ if (cbt->circuit_build_times[i] > max_timeout) {
+ build_time_t replaced = cbt->circuit_build_times[i];
+ num_filtered++;
+ cbt->circuit_build_times[i] = CBT_BUILD_TIMEOUT;
+
+ 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;
+}
+
+/**
* Load histogram from <b>state</b>, shuffling the resulting array
* after we do so. Use this result to estimate parameters and
* calculate the timeout.
@@ -535,7 +575,7 @@ circuit_build_times_parse_state(circuit_build_times_t *cbt,
int tot_values = 0;
uint32_t loaded_cnt = 0, N = 0;
config_line_t *line;
- int i;
+ unsigned int i;
build_time_t *loaded_times;
circuit_build_times_init(cbt);
*msg = NULL;
@@ -581,7 +621,8 @@ circuit_build_times_parse_state(circuit_build_times_t *cbt,
break;
}
- if (loaded_cnt+count > state->TotalBuildTimes) {
+ if (loaded_cnt+count+state->CircuitBuildTimeoutCount
+ > state->TotalBuildTimes) {
log_warn(LD_CIRC,
"Too many build times in state file. "
"Stopping short before %d",
@@ -600,10 +641,17 @@ circuit_build_times_parse_state(circuit_build_times_t *cbt,
}
}
+ log_info(LD_CIRC,
+ "Adding %d timeouts.", state->CircuitBuildTimeoutCount);
+ for (i=0; i < state->CircuitBuildTimeoutCount; i++) {
+ loaded_times[loaded_cnt++] = CBT_BUILD_TIMEOUT;
+ }
+
if (loaded_cnt != state->TotalBuildTimes) {
log_warn(LD_CIRC,
"Corrupt state file? Build times count mismatch. "
- "Read %d, file says %d", loaded_cnt, state->TotalBuildTimes);
+ "Read %d times, but file says %d", loaded_cnt,
+ state->TotalBuildTimes);
}
circuit_build_times_shuffle_and_store_array(cbt, loaded_times, loaded_cnt);
@@ -619,7 +667,13 @@ circuit_build_times_parse_state(circuit_build_times_t *cbt,
tot_values, cbt->total_build_times, N);
tor_assert(cbt->total_build_times == tot_values);
tor_assert(cbt->total_build_times <= CBT_NCIRCUITS_TO_OBSERVE);
+
circuit_build_times_set_timeout(cbt);
+
+ if (!state->CircuitBuildTimeoutCount) {
+ circuit_build_times_filter_timeouts(cbt);
+ }
+
tor_free(loaded_times);
return *msg ? -1 : 0;
}
@@ -676,6 +730,9 @@ circuit_build_times_update_alpha(circuit_build_times_t *cbt)
a += timeout_count*tor_mathlog(max_time);
a -= n*tor_mathlog(cbt->Xm);
+ // Estimator comes from Eq #4 in:
+ // "Bayesian estimation based on trimmed samples from Pareto populations"
+ // by Arturo J. Fernández. We are right-censored only.
a = (n-timeout_count)/a;
cbt->alpha = a;
@@ -1015,55 +1072,6 @@ circuit_build_times_add_timeout(circuit_build_times_t *cbt,
return 1;
}
-static int
-circuit_build_times_filter_timeouts(circuit_build_times_t *cbt)
-{
- int num_filtered=0, i=0;
- 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
- * really close to the current timeout value, which makes the next
- * alpha even higher, which makes us filter out more, and this becomes
- * progressively worse until the timeout *is* Xm. Filtering should
- * only be done on really shallow curves anyway. */
- if (cbt->alpha > 1.5) {
- return 0;
- }
-
- /* Do not filter for unit tests. They expect the distribution to be
- * unchanged from run to run. */
- if (unit_tests) {
- return 0;
- }
-
- timeout_rate = circuit_build_times_timeout_rate(cbt);
- max_timeout = /*(build_time_t)tor_lround(circuit_build_times_calculate_timeout(cbt,
- circuit_build_times_max_synthetic_quantile()));*/
- (build_time_t)cbt->timeout_ms;
-
- /* XXX: Make a special bin for timeout values */
- for (i = 0; i < CBT_NCIRCUITS_TO_OBSERVE; i++) {
- if (cbt->circuit_build_times[i] > max_timeout) {
- build_time_t replaced = cbt->circuit_build_times[i];
- num_filtered++;
- cbt->circuit_build_times[i] = CBT_BUILD_TIMEOUT;
-
- 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;
-}
-
/**
* Estimate a new timeout based on history and set our timeout
* variable accordingly.
@@ -1091,16 +1099,11 @@ void
circuit_build_times_set_timeout(circuit_build_times_t *cbt)
{
long prev_timeout = tor_lround(cbt->timeout_ms/1000);
- int filtered=0;
double timeout_rate;
if (!circuit_build_times_set_timeout_worker(cbt))
return;
- if ((filtered = circuit_build_times_filter_timeouts(cbt)) > 0) {
- circuit_build_times_set_timeout_worker(cbt);
- }
-
if (cbt->timeout_ms < circuit_build_times_min_timeout()) {
log_warn(LD_CIRC, "Set buildtimeout to low value %lfms. Setting to %dms",
cbt->timeout_ms, circuit_build_times_min_timeout());
diff --git a/src/or/config.c b/src/or/config.c
index 77ef45e..c3b4fc9 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -421,6 +421,7 @@ static config_var_t _state_vars[] = {
V(LastWritten, ISOTIME, NULL),
V(TotalBuildTimes, UINT, NULL),
+ V(CircuitBuildTimeoutCount, UINT, "0"),
VAR("CircuitBuildTimeBin", LINELIST_S, BuildtimeHistogram, NULL),
VAR("BuildtimeHistogram", LINELIST_V, BuildtimeHistogram, NULL),
diff --git a/src/or/or.h b/src/or/or.h
index d1b3661..49abf55 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2841,7 +2841,8 @@ typedef struct {
/** Build time histogram */
config_line_t * BuildtimeHistogram;
- uint16_t TotalBuildTimes;
+ unsigned int TotalBuildTimes;
+ unsigned int CircuitBuildTimeoutCount;
/** What version of Tor wrote this state file? */
char *TorVersion;
--
1.7.1
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