Telemetry

[datho7561]

Implement telemetry. Please refer to USAGE_DATA.md to see which data is collected.
Closes #415

[datho7561]

Going to rebase onto #421 once its merged, marking this PR as ready for review.

[rgrunber]

I've observed that if I replace the default segment key with the debug one (ie. always use debug), rebuild vscode-commons, and install it along with this vscode-xml change then events are always logged, and it's working as expected.

If not, I only seem to see events recorded when I'm debugging.

[fbricon]

I've observed that if I replace the default segment key with the debug one (ie. always use debug), rebuild vscode-commons, and install it along with this vscode-xml change then events are always logged, and it's working as expected.

If not, I only seem to see events recorded when I'm debugging.

Yes, as explained in https://github.com/redhat-developer/vscode-commons/blob/master/INSTRUCTIONS.md#optional-add-a-custom-segment-key-in-packagejson-file

[fbricon]

Can we track binary downloads (and failures)?

[rgrunber]

The binary url response gets piped into a local file, and the 'finish' event seems like a good place to record that (for zip or binary case). See https://github.com/redhat-developer/vscode-xml/blob/master/src/server/binary/binaryServerStarter.ts#L232 . Failures can be tracked as well in downloadBinary() .

@datho7561 , feel free to add these events (dowload success + failure) and we can test.

[datho7561]

I attached telemetry events to binary download success/failure.

[rgrunber]

I think we can merge this when ready. I can confirm that success/failure do get logged.

[datho7561]

Okay. I am ready to merge if you approve the PR.

[rgrunber]

Looks good. Let's get this in.