C# Library StackExchange.Redis Missing IPv6 Support

[zhlsunshine]

C# library StackExchange.Redis for demo service cartservice can not support IPv6. Below are some detail information:

All microservice pods are running well, except cartservice

$ kubectl get pods -o wide
NAME                                     READY   STATUS             RESTARTS      AGE    IP                               NODE          NOMINATED NODE   READINESS GATES
adservice-744f87d6bd-m5qgl               1/1     Running            0             84s    2001:db8:1234:5678:8:2:4f:a012   zhlsunshine   <none>           <none>
cartservice-cfbf8d6f-f5xtw               0/1     CrashLoopBackOff   3 (27s ago)   85s    2001:db8:1234:5678:8:2:4f:a017   zhlsunshine   <none>           <none>
checkoutservice-6b4b4f77f4-nw5js         1/1     Running            0             85s    2001:db8:1234:5678:8:2:4f:a01b   zhlsunshine   <none>           <none>
currencyservice-f6d848d9d-ccvkp          1/1     Running            0             84s    2001:db8:1234:5678:8:2:4f:a011   zhlsunshine   <none>           <none>
emailservice-6f56fbcd98-kghvd            1/1     Running            0             85s    2001:db8:1234:5678:8:2:4f:a00c   zhlsunshine   <none>           <none>
frontend-df498668b-8mcl9                 1/1     Running            0             85s    2001:db8:1234:5678:8:2:4f:a010   zhlsunshine   <none>           <none>
loadgenerator-5544bc469c-c6vx6           1/1     Running            0             85s    2001:db8:1234:5678:8:2:4f:a01a   zhlsunshine   <none>           <none>
paymentservice-597b54dcbb-xmng8          1/1     Running            0             85s    2001:db8:1234:5678:8:2:4f:a00a   zhlsunshine   <none>           <none>
productcatalogservice-5f7ff554c8-5slcb   1/1     Running            0             85s    2001:db8:1234:5678:8:2:4f:a015   zhlsunshine   <none>           <none>
recommendationservice-68599c67cb-kfh8j   1/1     Running            0             85s    2001:db8:1234:5678:8:2:4f:a013   zhlsunshine   <none>           <none>
redis-cart-757f95b597-8ftts              1/1     Running            0             84s    2001:db8:1234:5678:8:2:4f:a014   zhlsunshine   <none>           <none>
redis-cli-547c68d454-kmwfs               1/1     Running            0             106m   2001:db8:1234:5678:8:2:4f:a0e6   zhlsunshine   <none>           <none>
shippingservice-6565786ccd-qggnb         1/1     Running            0             84s    2001:db8:1234:5678:8:2:4f:a019   zhlsunshine   <none>           <none>
sleep-557747455f-l7mw4                   1/1     Running            0             20h    2001:db8:1234:5678:8:2:4f:a06d   zhlsunshine   <none>           <none>

And error logs shows as below:

$ kubectl logs cartservice-cfbf8d6f-f5xtw
Connecting to Redis: redis-cart:6379,ssl=false,allowAdmin=true,abortConnect=false
Wasn't able to connect to redis
Unhandled exception. System.ApplicationException: Wasn't able to connect to redis
   at cartservice.cartstore.RedisCartStore.EnsureRedisConnected()
   at cartservice.cartstore.RedisCartStore.InitializeAsync()
   at cartservice.Startup.ConfigureServices(IServiceCollection services)
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Microsoft.AspNetCore.Hosting.MethodInfoExtensions.InvokeWithoutWrappingExceptions(MethodInfo methodInfo, Object obj, Object[] parameters)
   at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.InvokeCore(Object instance, IServiceCollection services)
   at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.<>c__DisplayClass9_0.<Invoke>g__Startup|0(IServiceCollection serviceCollection)
   at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.Invoke(Object instance, IServiceCollection services)
   at Microsoft.AspNetCore.Hosting.ConfigureServicesBuilder.<>c__DisplayClass8_0.<Build>b__0(IServiceCollection services)
   at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.UseStartup(Type startupType, HostBuilderContext context, IServiceCollection services, Object instance)
   at Microsoft.AspNetCore.Hosting.GenericWebHostBuilder.<>c__DisplayClass13_0.<UseStartup>b__0(HostBuilderContext context, IServiceCollection services)
   at Microsoft.Extensions.Hosting.HostBuilder.CreateServiceProvider()
   at Microsoft.Extensions.Hosting.HostBuilder.Build()
   at <Program>$.<Main>$(String[] args)

After my investigation, this was caused by C# library of StackExchange.Redis which can not support IPv6. However, I also notice that there is a repo for IPv6: https://www.nuget.org/packages/StackExchange.Redis.IPv6/, however, unfortunately, it does not work. So I new this issue, and hope anyone can help to handle this, thanks!

[ahmetb]

Sounds like you should follow up with the library itself? But it also could be a Kubernetes/cluster issue. Not sure how much we can do here to address it especially if the IPv6 specific library also doesn’t work for you.

[zhlsunshine]

Sounds like you should follow up with the library itself? But it also could be a Kubernetes/cluster issue. Not sure how much we can do here to address it especially if the IPv6 specific library also doesn’t work for you.

Hi @ahmetb, I do not think there are something wrong with Kubernetes/cluster issue, I have debugged other services of this demo and it's okay for them, except cartservice which use C# library StackExchange.Redis. And the reason is that cartservice can not listen on IPv6, so make it easier, cartservice as a webservice should be able to listen on [::1] IPv6 format.
However, thank you for your reply!

[ahmetb]

Ah, the interface binding makes sense. I think the patches would be appreciated if there's an easy fix.

[zhlsunshine]

Ah, the interface binding makes sense. I think the patches would be appreciated if there's an easy fix.

I'm sorry that I am not good at C#. However, I will find some help if possible.

[bourgeoisor]

@NimJay do you think this will be taken care of (or has been taken care of) by the Renovate deps bumps? (#728)

[mathieu-benoit]

Hi @zhlsunshine, do you still have access to your environment with IPv6? If yes, could you please test again the cartservice with this new image: gcr.io/online-boutique-ci/refs/pull/838/cartservice:838 and report back here to see if it's now working? Thanks!

FYI: with this new image coming from the in-progress PR #838, the intent is to simplify and review the interaction between cartservice and the redis database.

[mathieu-benoit]

Hi @zhlsunshine, you could now try with the official v0.3.8 release: https://github.com/GoogleCloudPlatform/microservices-demo/releases/tag/v0.3.8. We improved cartservice’s Redis interaction by utilizing IDistributedCache (#838)

We would appreciate if you could share with us the results of your tests.

Closing this issue for now.

If you still have the issue, feel free to let us know + could you comment and add more details in the following thread please? StackExchange/StackExchange.Redis#1422

[mathieu-benoit]

JFYI: the issue is still here as per: #1340 (comment). Reopening it in order to better track it alongside: #1221.