Set ProfilingId from Profiler?

[glensc]

In mongo saver there's getLastProfilingId method:

• https://github.com/perftools/xhgui-collector/blob/1.8.1/src/Xhgui/Saver/Mongo.php#L41-L50

that has a side-effect, that if this saver is called in the application side, the id would be re-used for multiple profilings.

I don't know if that's deliberate or not, but using other savers this functionality is not present.

Question:

• should the id be generated on the profiler side or xhgui side?

Having it profiler side could overwrite (accidentally or deliberately) existing profiling. I don't think saving the same id twice will merge the results?

Having it set at the profiler side, allows the profiler to control the id value.

and if reading the importer section:

• https://github.com/perftools/xhgui#profiling-a-web-request-or-cli-script

it says importing the same profile twice creates duplicate profiling, so the duplicate id sent from profiler is not overwriting other profilers? is there any point then having value re-used? set from profiler?

cc @perftools/maintainers

[glensc]

Considering this issue:

• Profile multiple runs on the same script - document rules of aggregation/skipping xhgui#274

I think there should be no way for the profiler (saver) to specify _id, i.e every submit should be accepted as new profiling submit.

[glensc]

Unit tests in xhgui assume the _id can be set by fixture, and therefore the tests fail because PDO driver doesn't allow it:

1) XHGui\Test\Controller\RunTest::testCallgraph
Exception: No profile data found.

• https://travis-ci.org/github/perftools/xhgui/jobs/730020468

[glensc]

Allow id-override in pdo saver:

• PdoSaver: Allow _id override for unit testing xhgui#339

similarly in mongo saver:

• Backend decoupling xhgui-collector#11

but the override is there just to allow testing, at least for pdo.

[markstory]

It would be simpler if the clients didn't generate ids. That would allow the server and each storage implementation to generate the appropriate ID as required. It also prevents duplicate IDs from being created.

[glensc]

thanks, @markstory I've come to the same conclusion, just haven't got around to implementing it so.

[glensc]

also, the import method should return the id in the response:

• Update import to include saved id in response xhgui#345

[glensc]

ignoring Id from saver if one is provided:

• Allow overriding saver id only via id parameter xhgui#348

[glensc]

Providing id from profiler is no longer supported with latest xhgui (it's ignored).

[glensc]

The getLastProfilingId() was added in:

• Initiate profiling ID early xhgui-collector#2

it was a mistake and is removed by now.

a better approach, if need to identify requests and profilers, is to use UNIQUE_ID in env:

• Add Apache mod_unique_id UNIQUE_ID to server whitelist #55