Open yangbodong22011 opened 5 days ago
@mgravell Can you fix it ?
This is ... odd; short term, switching up to transactions will enforce single connection, but... this is odd; I'd have to investigate, which I can add to the list, but I can't guarantee a "today" thing
As both theses lines are not awaited
batch.HashSetAsync("testhash", keyval.ToArray()); // HMSET
batch.KeyExpireAsync("testhash", TimeSpan.FromSeconds(100)); // EXPIRE
There is no garantee of order. Just probability that line 1 would be executed earlier, but not garantee. Right ?
Edit: didn't see it is about batch. My bad, my remark is irrelevant
It is reasonable to expect this to occur in order; what is described is definitely not "working as intended", but it doesn't sound trivial - it will need some investigation
@mgravell I sent you the account and password of the test instance environment via google mail.
Backgroud
Our user told us that when they use batch on our cloud (AlibabaCloud), their commands came out of order. code is below
Ideally, they would get the following sequence:
But sometimes, the following sequence is produced:
Going a step further, we found that
UNLINK
andEXPIRE
are sent over one TCP connection, butHMSET
uses another TCP connection.Why are there two links? We found that when connecting through a domain name, there will be two links in
ConnectionMultiplexer#ServerSnapshot
(one is the domain name, and the other is the IP resolved by the domain name (obtained through cluster nodes)). Therefore, two links will be returned randomly inAnyServer
, causing commands to be assigned to different connections.How to reproduction
How to fix
During the initialization process, Lettuce will generate the result of the domain name as a URI, but will change the domain name to an alias. Please refer to https://github.com/redis/lettuce/commit/16f9e7525068a3887f5cc746c6b976720835600a
Version