[tor-commits] [tor/main] relay: Change DNS timeout label on MetricsPort
ahf at torproject.org
ahf at torproject.org
Wed Dec 15 12:47:55 UTC 2021
commit bf1ed5c8534c515bf1ee39bfbf8c340d704b4490
Author: David Goulet <dgoulet at torproject.org>
Date: Mon Dec 13 10:44:24 2021 -0500
relay: Change DNS timeout label on MetricsPort
Change it from "timeout" to "tor_timeout" in order to indicate that the
DNS timeout is one from tor's DNS threshold and not the DNS server
itself.
Fixes #40527
Signed-off-by: David Goulet <dgoulet at torproject.org>
---
changes/ticket40527 | 6 +++
src/feature/nodelist/networkstatus.c | 1 -
src/feature/relay/relay_metrics.c | 2 +-
src/feature/stats/rephist.c | 88 ++----------------------------------
src/feature/stats/rephist.h | 2 -
5 files changed, 10 insertions(+), 89 deletions(-)
diff --git a/changes/ticket40527 b/changes/ticket40527
index 631b3d4bb9..25bf6c57e3 100644
--- a/changes/ticket40527
+++ b/changes/ticket40527
@@ -3,3 +3,9 @@
timeouts are different from DNS server timeout. They have to be seen as
timeout related to UX and not because of a network problem. Fixes bug
40527; bugfix on 0.4.6.1-alpha.
+ - Change the MetricsPort DNS "timeout" label to be "tor_timeout" in order
+ to indicate that this was a DNS timeout from tor perspective and not the
+ DNS server itself.
+ - Deprecate overload_dns_timeout_period_secs and
+ overload_dns_timeout_scale_percent consensus parameters as well. They
+ were used to assess the overload state which is no more now.
diff --git a/src/feature/nodelist/networkstatus.c b/src/feature/nodelist/networkstatus.c
index d57db4c415..77e2b547f5 100644
--- a/src/feature/nodelist/networkstatus.c
+++ b/src/feature/nodelist/networkstatus.c
@@ -1666,7 +1666,6 @@ notify_before_networkstatus_changes(const networkstatus_t *old_c,
dos_consensus_has_changed(new_c);
relay_consensus_has_changed(new_c);
hs_dos_consensus_has_changed(new_c);
- rep_hist_consensus_has_changed(new_c);
}
/* Called after a new consensus has been put in the global state. It is safe
diff --git a/src/feature/relay/relay_metrics.c b/src/feature/relay/relay_metrics.c
index 0886b6ae87..fc8eb10d1b 100644
--- a/src/feature/relay/relay_metrics.c
+++ b/src/feature/relay/relay_metrics.c
@@ -161,7 +161,7 @@ fill_dns_error_values(void)
{ .name = "refused", .key = DNS_ERR_REFUSED },
{ .name = "truncated", .key = DNS_ERR_TRUNCATED },
{ .name = "unknown", .key = DNS_ERR_UNKNOWN },
- { .name = "timeout", .key = DNS_ERR_TIMEOUT },
+ { .name = "tor_timeout", .key = DNS_ERR_TIMEOUT },
{ .name = "shutdown", .key = DNS_ERR_SHUTDOWN },
{ .name = "cancel", .key = DNS_ERR_CANCEL },
{ .name = "nodata", .key = DNS_ERR_NODATA },
diff --git a/src/feature/stats/rephist.c b/src/feature/stats/rephist.c
index 68c9349bc3..5ff4ef1d2e 100644
--- a/src/feature/stats/rephist.c
+++ b/src/feature/stats/rephist.c
@@ -219,33 +219,6 @@ static uint64_t stats_n_tcp_exhaustion = 0;
/***** DNS statistics *****/
-/* We use a scale here so we can represent percentages with decimal points by
- * scaling the value by this factor and so 0.5% becomes a value of 500.
- * Default is 1% and thus min and max range is 0 to 100%. */
-#define OVERLOAD_DNS_TIMEOUT_PERCENT_SCALE 1000.0
-#define OVERLOAD_DNS_TIMEOUT_PERCENT_DEFAULT 1000
-#define OVERLOAD_DNS_TIMEOUT_PERCENT_MIN 0
-#define OVERLOAD_DNS_TIMEOUT_PERCENT_MAX 100000
-
-/** Consensus parameter: indicate what fraction of DNS timeout errors over the
- * total number of DNS requests must be reached before we trigger a general
- * overload signal .*/
-static double overload_dns_timeout_fraction =
- OVERLOAD_DNS_TIMEOUT_PERCENT_DEFAULT /
- OVERLOAD_DNS_TIMEOUT_PERCENT_SCALE / 100.0;
-
-/* Number of seconds for the assessment period. Default is 10 minutes (600) and
- * the min max range is within a 32bit value. */
-#define OVERLOAD_DNS_TIMEOUT_PERIOD_SECS_DEFAULT (10 * 60)
-#define OVERLOAD_DNS_TIMEOUT_PERIOD_SECS_MIN 0
-#define OVERLOAD_DNS_TIMEOUT_PERIOD_SECS_MAX INT32_MAX
-
-/** Consensus parameter: Period, in seconds, over which we count the number of
- * DNS requests and timeout errors. After that period, we assess if we trigger
- * an overload or not. */
-static int32_t overload_dns_timeout_period_secs =
- OVERLOAD_DNS_TIMEOUT_PERIOD_SECS_DEFAULT;
-
/** Overload DNS statistics. The information in this object is used to assess
* if, due to DNS errors, we should emit a general overload signal or not.
*
@@ -260,9 +233,6 @@ typedef struct {
* right before the DNS request is initiated. */
uint64_t stats_n_request;
- /** Total number of DNS timeout errors. */
- uint64_t stats_n_error_timeout;
-
/** When is the next assessment time of the general overload for DNS errors.
* Once this time is reached, all stats are reset and this time is set to the
* next assessment time. */
@@ -285,7 +255,7 @@ typedef struct {
/* Total number of DNS errors specific to libevent. */
uint64_t stats_n_error_truncated; /* 65 */
uint64_t stats_n_error_unknown; /* 66 */
- uint64_t stats_n_error_timeout; /* 67 */
+ uint64_t stats_n_error_tor_timeout; /* 67 */
uint64_t stats_n_error_shutdown; /* 68 */
uint64_t stats_n_error_cancel; /* 69 */
uint64_t stats_n_error_nodata; /* 70 */
@@ -337,48 +307,6 @@ get_dns_stats_by_type(const int type)
}
#endif
-/** Assess the DNS timeout errors and if we have enough to trigger a general
- * overload. */
-static void
-overload_general_dns_assessment(void)
-{
- /* Initialize the time. Should be done once. */
- if (overload_dns_stats.next_assessment_time == 0) {
- goto reset;
- }
-
- /* Not the time yet. */
- if (overload_dns_stats.next_assessment_time > approx_time()) {
- return;
- }
-
- reset:
- /* Reset counters for the next period. */
- overload_dns_stats.stats_n_error_timeout = 0;
- overload_dns_stats.stats_n_request = 0;
- overload_dns_stats.next_assessment_time =
- approx_time() + overload_dns_timeout_period_secs;
-}
-
-/** Called just before the consensus will be replaced. Update the consensus
- * parameters in case they changed. */
-void
-rep_hist_consensus_has_changed(const networkstatus_t *ns)
-{
- overload_dns_timeout_fraction =
- networkstatus_get_param(ns, "overload_dns_timeout_scale_percent",
- OVERLOAD_DNS_TIMEOUT_PERCENT_DEFAULT,
- OVERLOAD_DNS_TIMEOUT_PERCENT_MIN,
- OVERLOAD_DNS_TIMEOUT_PERCENT_MAX) /
- OVERLOAD_DNS_TIMEOUT_PERCENT_SCALE / 100.0;
-
- overload_dns_timeout_period_secs =
- networkstatus_get_param(ns, "overload_dns_timeout_period_secs",
- OVERLOAD_DNS_TIMEOUT_PERIOD_SECS_DEFAULT,
- OVERLOAD_DNS_TIMEOUT_PERIOD_SECS_MIN,
- OVERLOAD_DNS_TIMEOUT_PERIOD_SECS_MAX);
-}
-
/** Return the DNS error count for the given libevent DNS type and error code.
* The possible types are: DNS_IPv4_A, DNS_PTR, DNS_IPv6_AAAA. */
uint64_t
@@ -407,7 +335,7 @@ rep_hist_get_n_dns_error(int type, uint8_t error)
case DNS_ERR_UNKNOWN:
return dns_stats->stats_n_error_unknown;
case DNS_ERR_TIMEOUT:
- return dns_stats->stats_n_error_timeout;
+ return dns_stats->stats_n_error_tor_timeout;
case DNS_ERR_SHUTDOWN:
return dns_stats->stats_n_error_shutdown;
case DNS_ERR_CANCEL:
@@ -442,16 +370,6 @@ rep_hist_get_n_dns_request(int type)
void
rep_hist_note_dns_error(int type, uint8_t error)
{
- /* Assess if we need to trigger a general overload with regards to the DNS
- * errors or not. */
- overload_general_dns_assessment();
-
- /* Because of the libevent problem (see note in the function comment), we
- * disregard the DNS query type and keep track of DNS timeout for the
- * overload state. */
- if (error == DNS_ERR_TIMEOUT) {
- overload_dns_stats.stats_n_error_timeout++;
- }
overload_dns_stats.stats_n_request++;
/* Again, the libevent bug (see function comment), for an error that is
@@ -490,7 +408,7 @@ rep_hist_note_dns_error(int type, uint8_t error)
dns_stats->stats_n_error_unknown++;
break;
case DNS_ERR_TIMEOUT:
- dns_stats->stats_n_error_timeout++;
+ dns_stats->stats_n_error_tor_timeout++;
break;
case DNS_ERR_SHUTDOWN:
dns_stats->stats_n_error_shutdown++;
diff --git a/src/feature/stats/rephist.h b/src/feature/stats/rephist.h
index 6918ed18c2..7f414de4c8 100644
--- a/src/feature/stats/rephist.h
+++ b/src/feature/stats/rephist.h
@@ -89,8 +89,6 @@ uint64_t rep_hist_get_n_dns_request(int type);
void rep_hist_note_dns_request(int type);
void rep_hist_note_dns_error(int type, uint8_t error);
-void rep_hist_consensus_has_changed(const networkstatus_t *ns);
-
extern uint64_t rephist_total_alloc;
extern uint32_t rephist_total_num;
#ifdef TOR_UNIT_TESTS
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