I have performance issue when i get int value from redis cache

Hamza Taha 30

I use Azure Redis cache in the .net core 7 project
and I have an INT value and try to get it in the .net core 7 project.
but my problem is that getting the value from the Redis cache takes too long like 500 milliseconds, is there any reason for that?
this is the sample from the code :

public T Get<T>(string key)
        {
            string data = _cache.StringGet(key);
            if (!string.IsNullOrEmpty(data))
            {
                return JsonSerializer.Deserialize<T>(data);
            }
            return default(T);
        }

Mousa 5 Reputation points

2023-09-26T11:25:20.2933333+00:00

I have faced this issue

JasonPan - MSFT 4,551 Microsoft Vendor

Hi @Hamza Taha,

Try to use below code and share more details for me.

public T Get<T>(string key)
{
    var sw = Stopwatch.StartNew(); // Start a stopwatch to measure time
    
    string data = _cache.StringGet(key);
    
    sw.Stop(); // Stop the stopwatch after getting the data
    Console.WriteLine($"Time taken to get data from Redis: {sw.ElapsedMilliseconds} ms");
    
    if (!string.IsNullOrEmpty(data))
    {
        sw.Restart(); // Restart the stopwatch to measure deserialization time
        
        var result = JsonSerializer.Deserialize<T>(data);
        
        sw.Stop(); // Stop the stopwatch after deserialization
        Console.WriteLine($"Time taken for deserialization: {sw.ElapsedMilliseconds} ms");
        
        return result;
    }
    
    Console.WriteLine("Data is null or empty");
    return default(T);
}

Best Regards

Jason

Hamza Taha 30 Reputation points

2023-09-26T11:43:15.64+00:00

"Time taken to get data from Redis: 117 ms
Time taken for deserialization: 23 ms
JasonPan - MSFT 4,551 Reputation points Microsoft Vendor

2023-09-26T11:53:56.67+00:00

Hi @Hamza Taha,

Then the remaining 360ms, you need to look for it yourself.

Best Regards

Jason
Hamza Taha 30 Reputation points

2023-09-26T11:59:13.05+00:00

but i think is 113 milliseconds is too much

JasonPan - MSFT 4,551 Microsoft Vendor

Hi @Hamza Taha,

Please try to use async method, and try again. Once more thing, how about time-taken in local development ?

public async Task<T> GetAsync<T>(string key)
{
    var sw = Stopwatch.StartNew();
    
    string data = await _cache.StringGetAsync(key);
    
    sw.Stop();
    Console.WriteLine($"Time taken to get data from Redis: {sw.ElapsedMilliseconds} ms");
    
    if (!string.IsNullOrEmpty(data))
    {
        sw.Restart();
        
        var result = JsonSerializer.Deserialize<T>(data);
        
        sw.Stop();
        Console.WriteLine($"Time taken for deserialization: {sw.ElapsedMilliseconds} ms");
        
        return result;
    }
    
    Console.WriteLine("Data is null or empty");
    return default(T);
}

Best Regards

Jason

GeethaThatipatri-MSFT 27,987 Reputation points Microsoft Employee

2023-09-26T15:26:45.0133333+00:00

@Hamza Taha how you're measuring latency, like how you are testing this Get method, whether you setup the redis _cache connection in advance, and so on.

Regards

Geetha
Bruce (SqlWork.com) 58,126 Reputation points

2023-09-26T15:31:44.63+00:00

is your app hosted in the region as your azure redis?
GeethaThatipatri-MSFT 27,987 Reputation points Microsoft Employee

2023-10-12T14:08:29.6033333+00:00

@Hamza Taha Is your issue resolved?In case you already found a solution, would you please share it here with the community?

Regards

Geetha
Hamza Taha 30 Reputation points

2023-10-15T06:37:44.7866667+00:00
GeethaThatipatri-MSFT the issue still takes about 120 milliseconds I'm using the .net 7 and just the get from the cache takes this time just in this function
ConnectionMultiplexer _redisConnection;
redisConnection = ConnectionMultiplexer.Connect(connectionstring);
_cache = _redisConnection.GetDatabase();
this is the initialize for the Redis cache on my constructor
after that, the function takes about 120 milliseconds without the serialization part

public T Get<T>(string key) { string data = _cache.StringGet(key); if (!string.IsNullOrEmpty(data)) { return JsonSerializer.Deserialize<T>(data); } return default(T); }

2 answers

Bruce (SqlWork.com) 58,126 Reputation points

2023-10-15T16:56:57.24+00:00

You don’t really give us any information. What is you azure redis configuration, what is the payload size. What is your server’s latency to azure.

as it takes 23ms just to deserialize, I assume the payload is a fair size. Your 120ms does not seem unreasonable. A C0 resdis configuration is good for about 100mbps transfer rating, not counting latency.

See:

https://learn.microsoft.com/en-us/azure/azure-cache-for-redis/cache-troubleshoot-timeouts
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Hamza Taha 30 Reputation points

2023-10-16T07:15:15.6866667+00:00

I'm using a Redis C0 configuration, but only this line string data = _cache.StringGet(key); take about 120 milliseconds and i try to get an integer number just

Bruce (SqlWork.com) 58,126 Reputation points

2023-10-16T16:29:49.0833333+00:00

and is your app hosted in the same azure region? are you using a "live" connection, or does it need to connect?

Also measuring the performance of the fetch of small data is not very meaningful. you should benchmark the fetch of a more typical payload for your app.

Azure Resdis cache should have about the same performance a SQLServer for a simple table index access, but allow greater scaling. what does a single row index get from azure sql look like for your app?

if you are not gong to have 1000's of requests per second, than maybe a database may be a better solution.
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GeethaThatipatri-MSFT 27,987 Reputation points Microsoft Employee

2023-10-16T23:54:47.95+00:00
@Hamza Taha So, thanks for the added detail. I assume this isn't actually cross-region.

I see you're using a synchronous StringGet function, and I wonder what the circumstances you're testing it in are, and whether you are suffering from for instance, thread starvation, where the .net has to spin up more worker threads when you run out -- one reason for running out being blocking the threads with sync APIs like this.

I'd suggest you to:

refactor to await StringGetAsync

make sure you set a generous number of MinWorkerThreads so that there is no long delay to acquire worker threads if the thread pool gets empty

See the managed thread pool - .NET | Microsoft Learn

Regards

Geetha
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I have performance issue when i get int value from redis cache

2 answers