Merge pull request #3933 from matrix-org/erikj/destination_retry_cache

Add a five minute cache to get_destination_retry_timings
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Erik Johnston 2018-10-01 14:20:30 +02:00 committed by GitHub
commit 8f5c23d0cd
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3 changed files with 45 additions and 3 deletions

1
changelog.d/3933.misc Normal file
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@ -0,0 +1 @@
Add a cache to get_destination_retry_timings

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@ -23,6 +23,7 @@ from canonicaljson import encode_canonical_json
from twisted.internet import defer
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.util.caches.expiringcache import ExpiringCache
from ._base import SQLBaseStore, db_to_json
@ -49,6 +50,8 @@ _UpdateTransactionRow = namedtuple(
)
)
SENTINEL = object()
class TransactionStore(SQLBaseStore):
"""A collection of queries for handling PDUs.
@ -59,6 +62,12 @@ class TransactionStore(SQLBaseStore):
self._clock.looping_call(self._start_cleanup_transactions, 30 * 60 * 1000)
self._destination_retry_cache = ExpiringCache(
cache_name="get_destination_retry_timings",
clock=self._clock,
expiry_ms=5 * 60 * 1000,
)
def get_received_txn_response(self, transaction_id, origin):
"""For an incoming transaction from a given origin, check if we have
already responded to it. If so, return the response code and response
@ -155,6 +164,7 @@ class TransactionStore(SQLBaseStore):
"""
pass
@defer.inlineCallbacks
def get_destination_retry_timings(self, destination):
"""Gets the current retry timings (if any) for a given destination.
@ -165,10 +175,20 @@ class TransactionStore(SQLBaseStore):
None if not retrying
Otherwise a dict for the retry scheme
"""
return self.runInteraction(
result = self._destination_retry_cache.get(destination, SENTINEL)
if result is not SENTINEL:
defer.returnValue(result)
result = yield self.runInteraction(
"get_destination_retry_timings",
self._get_destination_retry_timings, destination)
# We don't hugely care about race conditions between getting and
# invalidating the cache, since we time out fairly quickly anyway.
self._destination_retry_cache[destination] = result
defer.returnValue(result)
def _get_destination_retry_timings(self, txn, destination):
result = self._simple_select_one_txn(
txn,
@ -196,6 +216,7 @@ class TransactionStore(SQLBaseStore):
retry_interval (int) - how long until next retry in ms
"""
self._destination_retry_cache.pop(destination)
return self.runInteraction(
"set_destination_retry_timings",
self._set_destination_retry_timings,

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@ -16,7 +16,7 @@
import logging
from collections import OrderedDict
from six import itervalues
from six import iteritems, itervalues
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.util.caches import register_cache
@ -24,6 +24,9 @@ from synapse.util.caches import register_cache
logger = logging.getLogger(__name__)
SENTINEL = object()
class ExpiringCache(object):
def __init__(self, cache_name, clock, max_len=0, expiry_ms=0,
reset_expiry_on_get=False, iterable=False):
@ -95,6 +98,21 @@ class ExpiringCache(object):
return entry.value
def pop(self, key, default=SENTINEL):
"""Removes and returns the value with the given key from the cache.
If the key isn't in the cache then `default` will be returned if
specified, otherwise `KeyError` will get raised.
Identical functionality to `dict.pop(..)`.
"""
value = self._cache.pop(key, default)
if value is SENTINEL:
raise KeyError(key)
return value
def __contains__(self, key):
return key in self._cache
@ -122,7 +140,7 @@ class ExpiringCache(object):
keys_to_delete = set()
for key, cache_entry in self._cache.items():
for key, cache_entry in iteritems(self._cache):
if now - cache_entry.time > self._expiry_ms:
keys_to_delete.add(key)
@ -146,6 +164,8 @@ class ExpiringCache(object):
class _CacheEntry(object):
__slots__ = ["time", "value"]
def __init__(self, time, value):
self.time = time
self.value = value