Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fix bug: client side caching causes unexpected disconnections #3160

Merged
merged 3 commits into from
Feb 28, 2024
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 3 additions & 1 deletion redis/_parsers/resp3.py
Original file line number Diff line number Diff line change
Expand Up @@ -117,7 +117,9 @@ def _read_response(self, disable_decoding=False, push_request=False):
)
for _ in range(int(response))
]
self.handle_push_response(response, disable_decoding, push_request)
response = self.handle_push_response(
response, disable_decoding, push_request
)
else:
raise InvalidResponse(f"Protocol Error: {raw!r}")

Expand Down
14 changes: 7 additions & 7 deletions redis/client.py
Original file line number Diff line number Diff line change
Expand Up @@ -563,10 +563,10 @@ def execute_command(self, *args, **options):
pool = self.connection_pool
conn = self.connection or pool.get_connection(command_name, **options)
response_from_cache = conn._get_from_local_cache(args)
if response_from_cache is not None:
return response_from_cache
else:
try:
try:
if response_from_cache is not None:
return response_from_cache
else:
response = conn.retry.call_with_retry(
lambda: self._send_command_parse_response(
conn, command_name, *args, **options
Expand All @@ -575,9 +575,9 @@ def execute_command(self, *args, **options):
)
conn._add_to_local_cache(args, response, keys)
return response
finally:
if not self.connection:
pool.release(conn)
finally:
if not self.connection:
pool.release(conn)

def parse_response(self, connection, command_name, **options):
"""Parses a response from the Redis server"""
Expand Down
2 changes: 1 addition & 1 deletion redis/commands/core.py
Original file line number Diff line number Diff line change
Expand Up @@ -2011,7 +2011,7 @@ def mget(self, keys: KeysT, *args: EncodableT) -> ResponseT:
options = {}
if not args:
options[EMPTY_RESPONSE] = []
options["keys"] = keys
options["keys"] = args
return self.execute_command("MGET", *args, **options)

def mset(self, mapping: Mapping[AnyKeyT, EncodableT]) -> ResponseT:
Expand Down
17 changes: 7 additions & 10 deletions redis/connection.py
Original file line number Diff line number Diff line change
@@ -1,6 +1,5 @@
import copy
import os
import select
import socket
import ssl
import sys
Expand Down Expand Up @@ -609,11 +608,6 @@ def pack_commands(self, commands):
output.append(SYM_EMPTY.join(pieces))
return output

def _socket_is_empty(self):
"""Check if the socket is empty"""
r, _, _ = select.select([self._sock], [], [], 0)
return not bool(r)

def _cache_invalidation_process(
self, data: List[Union[str, Optional[List[str]]]]
) -> None:
Expand All @@ -639,7 +633,7 @@ def _get_from_local_cache(self, command: str):
or command[0] not in self.cache_whitelist
):
return None
while not self._socket_is_empty():
while self.can_read():
self.read_response(push_request=True)
return self.client_cache.get(command)

Expand Down Expand Up @@ -1187,12 +1181,15 @@ def get_connection(self, command_name: str, *keys, **options) -> "Connection":
try:
# ensure this connection is connected to Redis
connection.connect()
# connections that the pool provides should be ready to send
# a command. if not, the connection was either returned to the
# if client caching is not enabled connections that the pool
# provides should be ready to send a command.
# if not, the connection was either returned to the
# pool before all data has been read or the socket has been
# closed. either way, reconnect and verify everything is good.
# (if caching enabled the connection will not always be ready
# to send a command because it may contain invalidation messages)
try:
if connection.can_read():
if connection.can_read() and connection.client_cache is None:
raise ConnectionError("Connection has data")
except (ConnectionError, OSError):
connection.disconnect()
Expand Down
43 changes: 43 additions & 0 deletions tests/test_cache.py
Original file line number Diff line number Diff line change
Expand Up @@ -146,6 +146,49 @@ def test_cache_return_copy(self, r):
check = cache.get(("LRANGE", "mylist", 0, -1))
assert check == [b"baz", b"bar", b"foo"]

@pytest.mark.onlynoncluster
@pytest.mark.parametrize(
"r",
[{"cache": _LocalCache(), "kwargs": {"decode_responses": True}}],
indirect=True,
)
def test_csc_not_cause_disconnects(self, r):
r, cache = r
id1 = r.client_id()
r.mset({"a": 1, "b": 1, "c": 1, "d": 1, "e": 1, "f": 1})
assert r.mget("a", "b", "c", "d", "e", "f") == ["1", "1", "1", "1", "1", "1"]
id2 = r.client_id()

# client should get value from client cache
assert r.mget("a", "b", "c", "d", "e", "f") == ["1", "1", "1", "1", "1", "1"]
assert cache.get(("MGET", "a", "b", "c", "d", "e", "f")) == [
"1",
"1",
"1",
"1",
"1",
"1",
]

r.mset({"a": 2, "b": 2, "c": 2, "d": 2, "e": 2, "f": 2})
id3 = r.client_id()
# client should get value from redis server post invalidate messages
assert r.mget("a", "b", "c", "d", "e", "f") == ["2", "2", "2", "2", "2", "2"]

r.mset({"a": 3, "b": 3, "c": 3, "d": 3, "e": 3, "f": 3})
# need to check that we get correct value 3 and not 2
assert r.mget("a", "b", "c", "d", "e", "f") == ["3", "3", "3", "3", "3", "3"]
# client should get value from client cache
assert r.mget("a", "b", "c", "d", "e", "f") == ["3", "3", "3", "3", "3", "3"]

r.mset({"a": 4, "b": 4, "c": 4, "d": 4, "e": 4, "f": 4})
# need to check that we get correct value 4 and not 3
assert r.mget("a", "b", "c", "d", "e", "f") == ["4", "4", "4", "4", "4", "4"]
# client should get value from client cache
assert r.mget("a", "b", "c", "d", "e", "f") == ["4", "4", "4", "4", "4", "4"]
id4 = r.client_id()
assert id1 == id2 == id3 == id4


@pytest.mark.skipif(HIREDIS_AVAILABLE, reason="PythonParser only")
@pytest.mark.onlycluster
Expand Down
Loading