[Question] Several "Unable to poll" errors multiple times per day

[poblouin]

Hey folks,

We've been using this ruby for quite a while, 1 year I would say and since then, we've been seeing a lot of "Unable to poll" errors. For example, last week, there were 700 of those for one of our service. This affects all our different using this sdk.

Unable to poll Workflow task queue

#<GRPC::Unavailable: 14:Socket closed. debug_error_string:{UNKNOWN:Error received from peer  {grpc_message:"Socket closed", grpc_status:14, created_time:"2024-03-19T14:52:38.963074635+00:00"}}>

And this

Unable to poll activity task queue

#<GRPC::Unavailable: 14:Socket closed. debug_error_string:{UNKNOWN:Error received from peer  {created_time:"2024-03-19T14:52:38.963058558+00:00", grpc_status:14, grpc_message:"Socket closed"}}>

Would someone have an idea of what might be causing those errors? Are they "normal" or expected from time to time within Temporal? We don't have a fancy configuration or anything we mostly use the default config and we use 20 as the thread pool size for both activity and workflow. I can share more relevant details if needed.

Note, this error doesn't cause any of our activities or workflows to fail, it just happens once every now and then and recovers.

temporal-ruby + grpc version

GIT
  remote: https://github.com/coinbase/temporal-ruby
  revision: 3e0dae708ec0e3eab8c44b57b64f5cd1881848e6
  
grpc (1.59.2)

[cdimitroulas]

For what it's worth, I also see this on our Ruby apps that use Temporal. I would love to understand more about why this happens.