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fix: retry hash clients when timeouts are reached #655

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fix: retry hash clients when timeouts are reached #655

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8 changes: 4 additions & 4 deletions pymemcache/client/hash.py
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Original file line number Diff line number Diff line change
Expand Up @@ -158,10 +158,10 @@ def _retry_dead(self) -> None:
current_time = time.time()
ldc = self._last_dead_check_time
# We have reached the retry timeout
if current_time - ldc > self.dead_timeout:
if current_time - ldc >= self.dead_timeout:
candidates = []
for server, dead_time in self._dead_clients.items():
if current_time - dead_time > self.dead_timeout:
if current_time - dead_time >= self.dead_timeout:
candidates.append(server)
for server in candidates:
logger.debug("bringing server back into rotation %s", server)
Expand Down Expand Up @@ -200,7 +200,7 @@ def _safely_run_func(self, client, func, default_val, *args, **kwargs):
# time lets just retry using it
if failed_metadata["attempts"] < self.retry_attempts:
failed_time = failed_metadata["failed_time"]
if time.time() - failed_time > self.retry_timeout:
if time.time() - failed_time >= self.retry_timeout:
logger.debug("retrying failed server: %s", client.server)
result = func(*args, **kwargs)
# we were successful, lets remove it from the failed
Expand Down Expand Up @@ -249,7 +249,7 @@ def _safely_run_set_many(self, client, values, *args, **kwargs):
# time lets just retry using it
if failed_metadata["attempts"] < self.retry_attempts:
failed_time = failed_metadata["failed_time"]
if time.time() - failed_time > self.retry_timeout:
if time.time() - failed_time >= self.retry_timeout:
logger.debug("retrying failed server: %s", client.server)
succeeded, failed, err = self._set_many(
client, values, *args, **kwargs
Expand Down
33 changes: 33 additions & 0 deletions pymemcache/test/test_client_hash.py
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Original file line number Diff line number Diff line change
Expand Up @@ -463,6 +463,7 @@ def test_server_encoding_client(self):
for client in hash_client.clients.values():
assert client.encoding == encoding

@mock.patch("pymemcache.client.hash.time.time", new=lambda: 100.0)
@mock.patch("pymemcache.client.hash.HashClient.client_class")
def test_dead_server_comes_back(self, client_patch):
client = HashClient([], dead_timeout=0, retry_attempts=0)
Expand All @@ -482,6 +483,7 @@ def test_dead_server_comes_back(self, client_patch):
assert client.get(b"key") == "Some value"
assert ("127.0.0.1", 11211) not in client._dead_clients

@mock.patch("pymemcache.client.hash.time.time", new=lambda: 100.0)
@mock.patch("pymemcache.client.hash.HashClient.client_class")
def test_failed_is_retried(self, client_patch):
client = HashClient([], retry_attempts=1, retry_timeout=0)
Expand Down Expand Up @@ -561,3 +563,34 @@ def test_legacy_add_remove_server_signature(self):
client.remove_server(server, server[-1])

# TODO: Test failover logic


@pytest.mark.unit
@pytest.mark.parametrize("timeout", [0, 5])
@pytest.mark.parametrize(
"command,argument,result",
[("get", b"key", b"value"), ("set_many", {b"key": b"value"}, [])],
)
def test_retry_at_timeout_boundary(timeout, command, argument, result):
with mock.patch("pymemcache.client.hash.time.time", return_value=100) as clock:
with mock.patch(
"pymemcache.client.hash.HashClient.client_class"
) as client_class:
client = HashClient([("localhost", 11211)], retry_timeout=timeout)
inner = client_class.return_value
inner.server = ("localhost", 11211)
method = getattr(inner, command)
method.side_effect = socket.timeout()
with pytest.raises(socket.timeout):
getattr(client, command)(argument)

method.side_effect = None
method.return_value = result
if timeout:
clock.return_value = 100 + timeout - 1
getattr(client, command)(argument)
assert method.call_count == 1

clock.return_value = 100 + timeout
assert getattr(client, command)(argument) == result
assert method.call_count == 2