问题
I am using Azure Redis (using Stackexchange.Redis) as a cache storage and its generally working fine. But I am getting timeouts errors now and then and I can't nail down why it is happening.
My redis connection settings:
value="dev.redis.cache.windows.net,ssl=true,password=secret,abortConnect=false,syncTimeout=3000"
I am getting all these exception in the same second (multiple calls): [I get these on GET operations aswell. Almost all these exceptions are on StringSet & StringGet. I rarely get exceptions on HashSets or HashGets]
Timeout performing SET {key}, inst: 1, mgr: ExecuteSelect, queue: 6, qu=0, qs=6, qc=0, wr=0/0, in=0/0
SocketFailure on SET
SocketFailure on SET
No connection is available to service this operation: SET
I am guessing that setting the object is taking longer than expected, this could be due to the object being large so I could potentially increase the synctimeout but would that be hiding some other problem?
I am only getting these exceptions on synchronous calls to stackexchange.redis, I have not seen an exception when the call is asynchronous.
Stacktrace:
StackExchange.Redis.RedisConnectionException: SocketFailure on SET
at StackExchange.Redis.ConnectionMultiplexer.ExecuteSyncImpl[T](Message message, ResultProcessor`1 processor, ServerEndPoint server) i
at StackExchange.Redis.RedisBase.ExecuteSync[T](Message message, ResultProcessor`1 processor, ServerEndPoint server)
at StackExchange.Redis.RedisDatabase.StringSet(RedisKey key, RedisValue value, Nullable`1 expiry, When when, CommandFlags flags)
at calling method
Edit: I am using StackExchange.Redis 1.0.414 package and I am using MessagePack to serialize my objects
回答1:
Timeouts are typically caused by one of a few things. Here are some examples
- Client or server CPU hitting 100%
- Poorly configured ThreadPool settings, combined with bursts of traffic
- Clients sending expensive commands to the server.
- Maxing out your network Bandwidth (on client or on server)
Tips for Client side issues: https://gist.github.com/JonCole/db0e90bedeb3fc4823c2
Tips for server side issues: https://gist.github.com/JonCole/9225f783a40564c9879d
I would recommend upgrading to a newer version of the StackExchange.Redis also. Version 1.1.603 has some more detailed diagnostic info in the timeout error message that may help you identify some of common client-side the things I listed above.
As for Socket failures, a couple of common causes for connection drops between the client and server that I have seen are:
- Scaling the client - I have seen brief client side connectivity issues when scaling client apps in Azure.
- When Redis is patched, there will be some connection blips. Azure Redis patching is explained here: https://gist.github.com/JonCole/317fe03805d5802e31cfa37e646e419d
来源：https://stackoverflow.com/questions/30811020/stackexchange-redis-timeouts-socketfailures