diff options
| author | Erik Johnston <erik@matrix.org> | 2019-08-20 11:46:00 +0100 |
|---|---|---|
| committer | Erik Johnston <erik@matrix.org> | 2019-08-20 11:46:00 +0100 |
| commit | 1dec31560e5712306e368a0adc6d9f84f924bdc9 (patch) | |
| tree | 6bb1a6633da9380a0a37775ab91f865a2c99274e | |
| parent | Fixup changelog and remove debug logging (diff) | |
| download | synapse-1dec31560e5712306e368a0adc6d9f84f924bdc9.tar.xz | |
Change jitter to be a factor rather than absolute value
| -rw-r--r-- | synapse/http/federation/well_known_resolver.py | 23 | ||||
| -rw-r--r-- | tests/http/federation/test_matrix_federation_agent.py | 4 |
2 files changed, 14 insertions, 13 deletions
diff --git a/synapse/http/federation/well_known_resolver.py b/synapse/http/federation/well_known_resolver.py index c846003886..5e9b0befb0 100644 --- a/synapse/http/federation/well_known_resolver.py +++ b/synapse/http/federation/well_known_resolver.py @@ -32,8 +32,8 @@ from synapse.util.metrics import Measure # period to cache .well-known results for by default WELL_KNOWN_DEFAULT_CACHE_PERIOD = 24 * 3600 -# jitter to add to the .well-known default cache ttl -WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER = 10 * 60 +# jitter factor to add to the .well-known default cache ttls +WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER = 0.1 # period to cache failure to fetch .well-known for WELL_KNOWN_INVALID_CACHE_PERIOD = 1 * 3600 @@ -133,16 +133,14 @@ class WellKnownResolver(object): # We have recently seen a valid well-known record for this # server, so we cache the lack of well-known for a shorter time. cache_period = WELL_KNOWN_DOWN_CACHE_PERIOD - cache_period += random.uniform( - 0, WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER - ) else: - # add some randomness to the TTL to avoid a stampeding herd every hour - # after startup cache_period = WELL_KNOWN_INVALID_CACHE_PERIOD - cache_period += random.uniform( - 0, WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER - ) + + # add some randomness to the TTL to avoid a stampeding herd + cache_period *= random.uniform( + 1 - WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER, + 1 + WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER, + ) if cache_period > 0: self._well_known_cache.set(server_name, result, cache_period) @@ -194,7 +192,10 @@ class WellKnownResolver(object): cache_period = WELL_KNOWN_DEFAULT_CACHE_PERIOD # add some randomness to the TTL to avoid a stampeding herd every 24 hours # after startup - cache_period += random.uniform(0, WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER) + cache_period *= random.uniform( + 1 - WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER, + 1 + WELL_KNOWN_DEFAULT_CACHE_PERIOD_JITTER, + ) else: cache_period = min(cache_period, WELL_KNOWN_MAX_CACHE_PERIOD) cache_period = max(cache_period, WELL_KNOWN_MIN_CACHE_PERIOD) diff --git a/tests/http/federation/test_matrix_federation_agent.py b/tests/http/federation/test_matrix_federation_agent.py index 4d3f31d18c..c55aad8e11 100644 --- a/tests/http/federation/test_matrix_federation_agent.py +++ b/tests/http/federation/test_matrix_federation_agent.py @@ -551,7 +551,7 @@ class MatrixFederationAgentTests(TestCase): self.assertEqual(self.well_known_cache[b"testserv"], b"target-server") # check the cache expires - self.reactor.pump((25 * 3600,)) + self.reactor.pump((48 * 3600,)) self.well_known_cache.expire() self.assertNotIn(b"testserv", self.well_known_cache) @@ -639,7 +639,7 @@ class MatrixFederationAgentTests(TestCase): self.assertEqual(self.well_known_cache[b"testserv"], b"target-server") # check the cache expires - self.reactor.pump((25 * 3600,)) + self.reactor.pump((48 * 3600,)) self.well_known_cache.expire() self.assertNotIn(b"testserv", self.well_known_cache) |