The crash in [1] should be investigated: it could be either due to us failing to cancel outgoing ping requests (in |TelemetrySend._cancelOutgoingRequests|) or some ping gets submitted and races to trigger a sendtask again. { "phase":"profile-before-change2", "conditions":[ { "name":"TelemetryController: shutting down", "state":{ "initialized":true, "initStarted":true, "haveDelayedInitTask":false, "shutdownBarrier":"Not started", "connectionsBarrier":"Not started", "sendModule":{ "sendingEnabled":false, "pendingPingRequestCount":2, "pendingPingActivityCount":1, "unpersistedPingCount":0, "persistedPingCount":2, "schedulerState":{ "shutdown":true, "hasSendTask":true, "sendsFailed":false, "sendTaskState":"wait on ping sends", "backoffDelay":60000 } } }, "filename":"resource://gre/modules/TelemetryController.jsm", "lineNumber":687, "stack":[ "resource://gre/modules/TelemetryController.jsm:setupTelemetry:687", "resource://gre/modules/TelemetryController.jsm:Impl.observe:780", "resource://gre/modules/TelemetryController.jsm:this.TelemetryController<.observe:167", "resource://gre/components/TelemetryStartup.js:TelemetryStartup.prototype.observe:30", "null:null:0" ] } ] } [1] - https://crash-stats.mozilla.com/report/index/27da41a1-63c7-43dc-9687-060322150711

This also seems related to bug 1173961. Also, TelemetrySend [1] seems to use |task.then(clear, clear)| to clear the sending task when done. As we found out in a recent bug, this pattern proved to be ineffective. We should probably do as done in [2]. [1] - http://mxr.mozilla.org/mozilla-central/source/toolkit/components/telemetry/TelemetrySend.jsm#374 [2] - https://hg.mozilla.org/mozilla-central/annotate/e7e69cc8c07b/toolkit/components/telemetry/TelemetryStorage.jsm#l832

Note that we can find the AsyncShutdown timeout crashes here: https://crash-stats.mozilla.com/search/?product=Firefox&release_channel=nightly&async_shutdown_timeout=sendModule&version=42.0a1&_facets=signature&_columns=date&_columns=signature&_columns=product&_columns=version&_columns=build_id&_columns=platform#crash-reports Only 4 related to Telemetry shutdown showed up so far since bug 1181553 landed. Of those, only one has an active send task - so far this doesn't seem to be a big issue.

moving to new milestone - [40b7], P2

There were no reports in the last week with an active send task on Nightly, lets keep watching this for a bit.

We should re-check if this is still an issue and, if that's the case, its volume.

There are <=5 of these on any channel. I'm willing to call these odd outliers until further evidence arrives.