CODEWITHSUNDEEP
c#redisredis-sentinel
Dean Thomas
Dean Thomas

Reputation: 1116

Redis Sentinel C# Client

I've got 3 redis servers, 1 master & 2 slaves. Currently just the 1 sentinel running, which is monitoring them all well. It will promote whichever instance when required and is really smooth.

The problem i currently have is communicating with it from C#. From my googling, it would appear that only csredis supports the sentinel for retrieving slaves/masters. So using code like this...

//Create a manager, which has all the sentinels in it (this would have 3 when we go live)
RedisSentinelManager sentman = new RedisSentinelManager("localhost:26379");

//Get a slave, as these are read-only
sentman.GetSlave("mymaster", 100, 100);

//Get a master, for storing an object
sentman.GetMaster("mymaster", 100, 100);

This works, absolutely fine and the various responses change when i kill an instance. However, it's incredibly slow!

If i create the manager and try and get the slave 5 times, then it takes around 1second per slave request, which is crazy slow. What i have noticed, is that the very first request is very, very fast. See the code below...

//Try and get 5 slaves
for ( int i = 0; i < 5; i ++ )
{
    Stopwatch a = Stopwatch.StartNew();
    var slave = sentman.GetSlave("mymaster", 50, 50);

    if (slave == null)
        Console.WriteLine("Failed to get slave");

    Console.WriteLine("Took " + a.ElapsedMilliseconds.ToString() + "ms to get " + slave.Host + ":" + slave.Port);
}

Here is the output...

Took 4ms to get localhost:6400
Took 844ms to get localhost:6400
Took 1007ms to get localhost:6400
Took 999ms to get localhost:6400
Took 994ms to get localhost:6400

Which is odd, the first one is 4ms! Then it's taking an age to get any subsequent clients. So i try another test, creating a new SentinelManager every loop item, is that faster? Nope, exactly the same. First one is very quick, then very very slow.

Am i using this library wrong, or have I found a bug? Going to try and grab the source and step through it...

Cheers guys...

Upvotes: 3

Views: 2288

Answers (1)

Dean Thomas
Dean Thomas

Reputation: 1116

I've found the problem here, it's an issue with the client. In it's dispose method it's taking around 1s to dispose of some async objects.

Upvotes: 1

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