Crash on Deno Deploy: Connection reset by peer

ConnectionReset: Connection reset by peer (os error 104)     
at async read (deno:ext/net/01_net.js:21:19)     
at async BufReader.read (https://deno.land/std@0.118.0/io/buffer.ts:314:18)     
at async BufReader.readFull (https://deno.land/std@0.118.0/io/buffer.ts:343:28)     
at async WireProtocol.receive (https://deno.land/x/mongo@v0.29.0/src/protocol/protocol.ts:77:34)

[manyuanrong]

This is indeed a problem with keepalive, which also exists in other database drivers of deno. I have recently used redis and pgsql in a production environment. Sending heartbeat requests regularly is simple and effective. Of course, this should also be added as a feature of the driver library.

[FinlayDaG33k]

I did manage to “circumvent” this issue for now by having my app make a small query every 5 seconds (might want to increase this but it’ll do for now), keeping the connection alive.
Because I use DangoDB and am not very knowledgeable on MongoDB, this was the easiest way for me to accomplish it for me.
A better solution will need to be built.

I don’t know how this will affect users of Deno Deploy since I am not familiar with the service.

EDIT: Here’s a little overview on when my app crashed (red section) vs after the “fix” (green section). Missing dots on the graph represent moments when the app crashed. As one can see, the crashing was pretty frequently before the fix and after it, it hasn’t crashed a single time yet.

Update after ~8 days

It’s been about 8-days now since I’ve added this and I haven’t had a single crash yet.
So it does seem that implementing some kind of keepalive may help solve this issue.