Improve redis handling

Remove bytes decoding that was moved into connection pool.

Moreover, improve logging in case of redis access problems in the
routing cache.

Author: garw

setup.py

@@ -8,7 +8,7 @@
 
 setup(
     name="ywsd",
-    version="0.14.0",
+    version="0.14.1",
     packages=["ywsd"],
     url="https://gitlab.rc5.de/eventphone/ywsd",
     license="AGPLv3+",

ywsd/busy_cache.py

@@ -100,10 +100,7 @@ async def is_busy(self, extension):
 
     async def busy_status(self):
         async with redis.Redis(connection_pool=self._yate.redis_pool) as client:
-            return {
-                k.decode("ascii"): int(v)
-                for k, v in (await client.hgetall("busy_cache")).items()
-            }
+            return {k: int(v) for k, v in (await client.hgetall("busy_cache")).items()}
 
     async def flush(self):
         async with redis.Redis(connection_pool=self._yate.redis_pool) as client:

ywsd/engine.py

@@ -210,7 +210,17 @@ def _call_route_handler(self, msg: Message) -> Optional[bool]:
 
     async def _retrieve_from_cache_for(self, msg: Message):
         called = "lateroute/" + msg.params.get("called")
-        result = await self._routing_cache.retrieve(called)
+        try:
+            result = await self._routing_cache.retrieve(called)
+        except Exception as e:
+            backtrace = traceback.format_exc()
+            logging.error(
+                "An error occurred while retrieving stored routing cache for target %s: %s\nBacktrace: %s",
+                called,
+                e,
+                backtrace,
+            )
+            raise
         if result is None:
             # This is an invalid entry, answer the message but with invalid result
             msg.result = ""

ywsd/routing_cache.py

@@ -53,20 +53,28 @@ def __init__(self, yate, settings):
         self._redis_pool = yate.redis_pool
 
     async def retrieve(self, target) -> Optional[IntermediateRoutingResult]:
-        async with redis.Redis(
-            connection_pool=self._redis_pool, decode_responses=True
-        ) as client:
-            data = await client.get(target)
+        async with redis.Redis(connection_pool=self._redis_pool) as client:
+            try:
+                data = await client.get(target)
+            except Exception as e:
+                logging.error(
+                    "Failure to retrieve cached routing result from redis: %s", e
+                )
+                raise
             if data is None:
                 return None
             data = json.loads(data)
             return IntermediateRoutingResult.deserialize(data)
 
     async def update(self, results: Dict[str, IntermediateRoutingResult]):
-        async with redis.Redis(
-            connection_pool=self._redis_pool, decode_responses=True
-        ) as client:
-            for key, routing_result in results.items():
-                await client.setex(
-                    key, self._object_lifetime, json.dumps(routing_result.serialize())
-                )
+        async with redis.Redis(connection_pool=self._redis_pool) as client:
+            try:
+                for key, routing_result in results.items():
+                    await client.setex(
+                        key,
+                        self._object_lifetime,
+                        json.dumps(routing_result.serialize()),
+                    )
+            except Exception as e:
+                logging.error("Failure to update cached routing in redis: %s", e)
+                raise