http2 (client): Error [ERR_HTTP2_INVALID_SESSION]: The session has been destroyed

[AndrewBarba]

• Version: Node.js 8.4.0
• Platform: Heroku
• Subsystem: Cedar-16 stack

I don't see this too often but once in a while it is showing up in my logs without a trace back to anything in my code. Below is a full class definition for a very basic http2-client library that I'm using to connect to Apple's HTTP/2 Push Notification API.

app/web.1: error:  Error [ERR_HTTP2_INVALID_SESSION]: The session has been destroyed 
app/web.1:     at ClientHttp2Session.shutdown (internal/http2/core.js:994:13) 
app/web.1:     at ClientHttp2Session.emitGoaway (internal/http2/core.js:377:10) 
app/web.1:     at _combinedTickCallback (internal/process/next_tick.js:131:7) 
app/web.1:     at process._tickDomainCallback (internal/process/next_tick.js:218:9) 
app/web.1: worker 1  disconnected. suicide false 

A couple things I could be doing incorrectly:

1. I am only connecting once and holding onto returned client for subsequent requests
2. I clean up the client only if .destroyed !== true or I receive a GOAWAY frame
3. I am setting up a request timeout but not a session timeout (didn't see docs for session timeout?)

Code:
https://github.com/AndrewBarba/apns2/blob/node/http2/lib/http2-client.js

[jasnell]

There's likely a race condition in the timeout code. The error is occurring because some bit of code (most likely the timeout) is attempting to fire after the session has already been destroyed. I'll take a look and verify.