Custom events cannot render in Appdash (cannot call RegisterEvent) about appdash HOT 5 OPEN

The root of this issue seems to be the annotation serialization model that we've chosen.

• To marshal or unmarshal an event, it must be registered.
• Registration must occur because there are various interfaces (TimespanEvent, TimestampedEvent, ImportantEvent) which direct information about the event type (e.g. for TimespanEvent it tells us which struct field exactly is the start and end times of the span).
• Without registration we cannot know the timespan times, important fields, etc.

The stringent requirement on event registration means that custom event types don't render properly when running the standalone appdash command (as shown above).

We could formalize the annotation (read: struct field) name for both the starting and ending times of a timespan (or the timestamp for a timestamped event) but this would effectively render the TimespanEvent interface a bit redundant (and users of it would soon find their events not rendering in the standalone appdash app).

The least imposing option I can think of is to keep the redundant TimespanEvent interface for legacy code, and encourage the use of a new type Timespan struct{StartTime, EndTime time.Time} structure (which would always have identical StartTime and EndTime annotation names, so the standalone app could always unmarshal at least a Timespan event for rendering).

from appdash.

The idea I had, without any idea of how possible or difficult it would be to implement: Tie the registration of the event to a collector, and send a "schema serialization" to the collector to inform it how a particularly named event is structured.

In our app we currently call appdash.RegisterEvent() in init(), but there's no reason why we couldn't call it after we create a collector.

from appdash.

@joeshaw Right, I think your solution would work. It does require a change to the core annotation serialization model, however.

I'm not opposed to changing the annotation serialization model, and it's required in order to fix this, but it does need some good thought on what the best approach is (how does Zipkin/Dapper handle it? what other approaches are there? etc), I just want to ensure the solution is not rushed 😄

For now I think the best approach is to require modification of the appdash executable's source code, which should be as simple as:

import "my/event/declarations"

(At least until I'm certain of a proper solution to this issue).

from appdash.

@slimsag yep, not trying to rush you on this. We've worked around this in the meantime exactly as you suggest. Thanks!

from appdash.

The proper solution here is probably the opentracing API which does not use custom event types but rather standard methods for adding tags/etc to spans.

from appdash.