Re: Proposal: add "group" concept to Performance Timeline

On Fri, Mar 20, 2015 at 10:44 AM, Ilya Grigorik <igrigorik@google.com>
wrote:

> ... and I believe that it's a generally useful and powerful concept that
> enables Performance Timeline to communicate event cascades.
>

Just realized that the "cascades" part is not true. As currently proposed
an event cannot simultaneously be part of a group and have its own
subtree... For that we'd need two fields: "parent" to link to another event
or logical group, plus an "id" field that can act as a parent key for other
events. That said, I'm not sure if we need this extra functionality... It
seems that simple (one level) groups may be sufficient for the current use
cases?

Some examples:
- Multi-req navigation: [nav-request{group: a}, redirected-req{group: a}]
- Multi-req resource fetch: [cors-request{group: b}, fetch-req{group: b}]
- Req + Server-Timing: [request{group: c}, server-timing{group: c}]
- Linking Frame-Timing events: [renderer{group: d}, composite{group: d},
composite:{group: d}]
- ...

Thoughts? Anything I'm forgetting or overlooking?