[or-cvs] [tor/master 03/10] Do away with the complexity of the network liveness detection.
arma at torproject.org
arma at torproject.org
Thu Sep 30 04:13:16 UTC 2010
Author: Mike Perry <mikeperry-git at fscked.org>
Date: Wed, 29 Sep 2010 08:55:11 -0700
Subject: Do away with the complexity of the network liveness detection.
Commit: 11910cf5b32edfd6b900386d37bb69c7592174c1
We really should ignore any timeouts that have *no* network activity for their
entire measured lifetime, now that we have the 95th percentile measurement
changes. Usually this is up to a minute, even on fast connections.
---
src/or/circuitbuild.c | 71 ++++++++++++++----------------------------------
src/or/or.h | 32 +---------------------
src/test/test.c | 26 ++++--------------
3 files changed, 28 insertions(+), 101 deletions(-)
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 81b63fe..234765b 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -306,6 +306,7 @@ circuit_build_times_init(circuit_build_times_t *cbt)
control_event_buildtimeout_set(cbt, BUILDTIMEOUT_SET_EVENT_RESET);
}
+#if 0
/**
* Rewind our build time history by n positions.
*/
@@ -332,6 +333,7 @@ circuit_build_times_rewind_history(circuit_build_times_t *cbt, int n)
"Rewound history by %d places. Current index: %d. "
"Total: %d", n, cbt->build_times_idx, cbt->total_build_times);
}
+#endif
/**
* Add a new build time value <b>time</b> to the set of build times. Time
@@ -941,8 +943,16 @@ circuit_build_times_needs_circuits_now(circuit_build_times_t *cbt)
void
circuit_build_times_network_is_live(circuit_build_times_t *cbt)
{
- cbt->liveness.network_last_live = approx_time();
- cbt->liveness.nonlive_discarded = 0;
+ time_t now = approx_time();
+ if (cbt->liveness.nonlive_timeouts > 0) {
+ log_notice(LD_CIRC,
+ "Tor now sees network activity. Restoring circuit build "
+ "timeout recording. Network was down for %ld seconds "
+ "during %d circuit attempts.",
+ (long int)now - cbt->liveness.network_last_live,
+ cbt->liveness.nonlive_timeouts);
+ }
+ cbt->liveness.network_last_live = now;
cbt->liveness.nonlive_timeouts = 0;
}
@@ -1002,9 +1012,16 @@ circuit_build_times_network_close(circuit_build_times_t *cbt,
now_buf);
}
cbt->liveness.nonlive_timeouts++;
- log_info(LD_CIRC,
+ if (cbt->liveness.nonlive_timeouts == 1) {
+ log_notice(LD_CIRC,
+ "Tor has not observed any network activity for the past %ld "
+ "seconds. Disabling circuit build timeout code.",
+ (long int)now - cbt->liveness.network_last_live);
+ } else {
+ log_info(LD_CIRC,
"Got non-live timeout. Current count is: %d",
cbt->liveness.nonlive_timeouts);
+ }
}
}
@@ -1018,54 +1035,8 @@ circuit_build_times_network_close(circuit_build_times_t *cbt,
int
circuit_build_times_network_check_live(circuit_build_times_t *cbt)
{
- time_t now = approx_time();
- if (cbt->liveness.nonlive_timeouts >= CBT_NETWORK_NONLIVE_DISCARD_COUNT) {
- if (!cbt->liveness.nonlive_discarded) {
- cbt->liveness.nonlive_discarded = 1;
- log_notice(LD_CIRC, "Network is no longer live (too many recent "
- "circuit timeouts). Dead for %ld seconds.",
- (long int)(now - cbt->liveness.network_last_live));
- /* Only discard NETWORK_NONLIVE_TIMEOUT_COUNT-1 because we stopped
- * counting after that */
- circuit_build_times_rewind_history(cbt,
- CBT_NETWORK_NONLIVE_TIMEOUT_COUNT-1);
- control_event_buildtimeout_set(cbt, BUILDTIMEOUT_SET_EVENT_DISCARD);
- }
- return 0;
- } else if (cbt->liveness.nonlive_timeouts >=
- CBT_NETWORK_NONLIVE_TIMEOUT_COUNT) {
- if (cbt->liveness.suspended_timeout <= 0) {
- cbt->liveness.suspended_timeout = cbt->timeout_ms;
- cbt->liveness.suspended_close_timeout = cbt->close_ms;
-
- if (cbt->timeout_ms < circuit_build_times_get_initial_timeout())
- cbt->timeout_ms = circuit_build_times_get_initial_timeout();
- else
- cbt->timeout_ms *= 2;
-
- if (cbt->close_ms < circuit_build_times_get_initial_timeout())
- cbt->close_ms = circuit_build_times_get_initial_timeout();
- else
- cbt->close_ms *= 2;
-
- log_notice(LD_CIRC,
- "Network is flaky. No activity for %ld seconds. "
- "Temporarily raising timeout to %lds.",
- (long int)(now - cbt->liveness.network_last_live),
- tor_lround(cbt->timeout_ms/1000));
- control_event_buildtimeout_set(cbt, BUILDTIMEOUT_SET_EVENT_SUSPENDED);
- }
-
+ if (cbt->liveness.nonlive_timeouts > 0) {
return 0;
- } else if (cbt->liveness.suspended_timeout > 0) {
- log_notice(LD_CIRC,
- "Network activity has resumed. "
- "Resuming circuit timeout calculations.");
- cbt->timeout_ms = cbt->liveness.suspended_timeout;
- cbt->close_ms = cbt->liveness.suspended_close_timeout;
- cbt->liveness.suspended_timeout = 0;
- cbt->liveness.suspended_close_timeout = 0;
- control_event_buildtimeout_set(cbt, BUILDTIMEOUT_SET_EVENT_RESUME);
}
return 1;
diff --git a/src/or/or.h b/src/or/or.h
index 6c398b7..dc46684 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2961,26 +2961,6 @@ typedef uint32_t build_time_t;
/** Save state every 10 circuits */
#define CBT_SAVE_STATE_EVERY 10
-/* Circuit Build Timeout network liveness constants */
-
-/**
- * Have we received a cell in the last N circ attempts?
- *
- * This tells us when to temporarily switch back to
- * BUILD_TIMEOUT_INITIAL_VALUE until we start getting cells,
- * at which point we switch back to computing the timeout from
- * our saved history.
- */
-#define CBT_NETWORK_NONLIVE_TIMEOUT_COUNT 3
-
-/**
- * This tells us when to toss out the last streak of N timeouts.
- *
- * If instead we start getting cells, we switch back to computing the timeout
- * from our saved history.
- */
-#define CBT_NETWORK_NONLIVE_DISCARD_COUNT (CBT_NETWORK_NONLIVE_TIMEOUT_COUNT*2)
-
/* Circuit build times consensus parameters */
/**
@@ -3021,9 +3001,7 @@ double circuit_build_times_quantile_cutoff(void);
#define CBT_DEFAULT_TIMEOUT_INITIAL_VALUE (60*1000)
int32_t circuit_build_times_initial_timeout(void);
-#if CBT_DEFAULT_MAX_RECENT_TIMEOUT_COUNT < 1 || \
- CBT_NETWORK_NONLIVE_DISCARD_COUNT < 1 || \
- CBT_NETWORK_NONLIVE_TIMEOUT_COUNT < 1
+#if CBT_DEFAULT_MAX_RECENT_TIMEOUT_COUNT < 1
#error "RECENT_CIRCUITS is set too low."
#endif
@@ -3033,8 +3011,6 @@ typedef struct {
time_t network_last_live;
/** If the network is not live, how many timeouts has this caused? */
int nonlive_timeouts;
- /** If the network is not live, have we yet discarded our history? */
- int nonlive_discarded;
/** Circular array of circuits that have made it to the first hop. Slot is
* 1 if circuit timed out, 0 if circuit succeeded */
int8_t *timeouts_after_firsthop;
@@ -3042,12 +3018,6 @@ typedef struct {
int num_recent_circs;
/** Index into circular array. */
int after_firsthop_idx;
- /** Timeout gathering is suspended if non-zero. The old timeout value
- * is stored here in that case. */
- double suspended_timeout;
- /** Timeout gathering is suspended if non-zero. The old close value
- * is stored here in that case. */
- double suspended_close_timeout;
} network_liveness_t;
/** Structure for circuit build times history */
diff --git a/src/test/test.c b/src/test/test.c
index d952832..8d8c46f 100644
--- a/src/test/test.c
+++ b/src/test/test.c
@@ -499,28 +499,14 @@ test_circuit_timeout(void)
build_times_idx = estimate.build_times_idx;
total_build_times = estimate.total_build_times;
- for (i = 0; i < CBT_NETWORK_NONLIVE_TIMEOUT_COUNT; i++) {
- test_assert(circuit_build_times_network_check_live(&estimate));
- test_assert(circuit_build_times_network_check_live(&final));
-
- circuit_build_times_count_close(&estimate, 0,
- (time_t)(approx_time()-estimate.close_ms/1000.0-1));
- circuit_build_times_count_close(&final, 0,
- (time_t)(approx_time()-final.close_ms/1000.0-1));
- }
-
- test_assert(!circuit_build_times_network_check_live(&estimate));
- test_assert(!circuit_build_times_network_check_live(&final));
- for ( ; i < CBT_NETWORK_NONLIVE_DISCARD_COUNT; i++) {
- circuit_build_times_count_close(&estimate, 0,
- (time_t)(approx_time()-estimate.close_ms/1000.0-1));
+ test_assert(circuit_build_times_network_check_live(&estimate));
+ test_assert(circuit_build_times_network_check_live(&final));
- if (i < CBT_NETWORK_NONLIVE_DISCARD_COUNT-1) {
- circuit_build_times_count_close(&final, 0,
- (time_t)(approx_time()-final.close_ms/1000.0-1));
- }
- }
+ circuit_build_times_count_close(&estimate, 0,
+ (time_t)(approx_time()-estimate.close_ms/1000.0-1));
+ circuit_build_times_count_close(&final, 0,
+ (time_t)(approx_time()-final.close_ms/1000.0-1));
test_assert(!circuit_build_times_network_check_live(&estimate));
test_assert(!circuit_build_times_network_check_live(&final));
--
1.7.1
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