Asynchronous call back of redis subscriber not called

[Arun210688]

I use Hiredis async feature for my publisher subscriber model.

Scenario :
When I execute PUBSUB CHANNELS from redis-cli , i can see all my 5 channels(channel1 to channel5) list.
When I publish an event to the first channel it will publish to 2nd channel , 2nd channel will publish to 3rd channel and it continues up to 5 channels.

Problem:
Most of the times the set up works fine .
But sometimes the message is received only by the 1st channel and get stuck , the callback of 2nd channel is not getting called . Even if I publish fresh data to channel1 , it is received by channel 1 but not cascaded to channel2
I need to completely restart both redis -server and my application to continue work.

Support needed

1. Can you help understand why the asynchronous call back of channel2 is not invoked. Is there any debug log messages that I can enable to look into the reason .
2. What all the possibility for this error scenario.
3. Is there any methods to check if there are any pending messages for a particular channel in the redis server that are not received by the clients.