Getting strange error regarding subchannels

[jakeleventhal]

Environment details

• OS: Mac OS 10.15 Beta (19A573a)
• Node.js version: v12.10.0
• npm version: 6.10.3
• @google-cloud/firestore version: 3.3.4

Steps to reproduce

I am unsure how to reproduce as there doesn't seem to be much indication in my logs.
The problem I have is that I keep getting this error popping up:

(node:33) UnhandledPromiseRejectionWarning: Error: 14 UNAVAILABLE: Failed to start call on picked subchannel
    at Object.callErrorFromStatus (/api/node_modules/@grpc/grpc-js/src/call.ts:79:24)
    at Http2CallStream.<anonymous> (/api/node_modules/@grpc/grpc-js/src/client.ts:155:18)
    at Http2CallStream.emit (events.js:333:22)
    at Http2CallStream.EventEmitter.emit (domain.js:485:12)
    at /api/node_modules/@grpc/grpc-js/src/call-stream.ts:183:14
    at processTicksAndRejections (internal/process/task_queues.js:79:11)

[schmidt-sebastian]

Thanks for the report!

@murgatroid99 Do you have any leads here? This might be specific to our SDK as we regularly delete and recreate clients, but it would be good to know if there was a way to avoid this issue.

[murgatroid99]

This error generally indicates that a connection dropped at almost the same time that we started a request on that connection. It's an UNAVAILABLE error to indicate that it can be retried, but I guess that doesn't help if the method can't be retried. It may be possible for grpc to handle that error without surfacing it to the user.

[schmidt-sebastian]

I moved this to grpc/grpc-node: grpc/grpc-node#1250

Let's track all work there.