1207743 - ack's not tracked on reconnect

Status: RESOLVED FIXED

(Core :: DOM: Push Subscriptions, defect, P3)

Description

[Ben Bangert [:benbangert]]

If the connection drops and ack's are in the _queue, they will not be retired, nor will knowledge of them be present. This means on reconnect, the notifications will come down, and processed again.

Sending the ack's on reconnect doesn't really help, since the notifications will be sent immediately by the server anwyays.

A more ideal solution might be having the client track the last N ack's, and if it sees a notification that it has already ack'd, then it drops it and sends another ack.

Comment 1

[Dragana Damjanovic [:dragana]]

This is for WebSocket and only for data  delivery with WebSocket? The notification when data is turned of have a version number, but semantics needs to be change for that one 
http://mxr.mozilla.org/mozilla-central/source/dom/push/PushServiceWebSocket.jsm#1055

Comment 2

[Ben Bangert [:benbangert]]

:kit did you want to follow up on this?

Comment 3

[Lina Butler (ex-Mozilla)]

I somehow missed this one. Sorry about that! We'll triage this tomorrow, but it sounds reasonable, especially if we're going to defer acks until we've finished processing the message (bug 1246341).

Comment 4

[Lina Butler (ex-Mozilla)]

Attachment: recents.patch

I think this should do it. This patch stores the 10 most recent message IDs for a subscription, and drops any dupes.

There's still the case where the user could close the browser after we store the message ID, but before we deliver the message to the service worker or ack it. ISTM that's OK, because the user could still close the browser after we ack the message, but before the worker could finish processing.

Comment 5

[Lina Butler (ex-Mozilla)]

Attachment: recents.patch

https://treeherder.mozilla.org/#/jobs?repo=try&revision=2b8a3ed0ff5f

Comment 6

[Ben Bangert [:benbangert]]

Looks fine to me.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/3943ac2a0fd1
Track recent push messages to avoid duplicate notifications on reconnect. r=dragana

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/3943ac2a0fd1