Multiple profiler traces get same base_id

[Stuart Grace]

OpenStack Queens release.

With developer panel and profiler enabled, you can select "Profile Current Page" to create a new profiler trace. That initializes a profiler instance here:

https://github.com/openstack/horizon/blob/master/openstack_dashboard/contrib/developer/profiler/middleware.py#L64

That instance is never deleted. The next time you select "Profile Current Page", the test here finds the previous instance and returns it, instead of creating a new instance:

https://github.com/openstack/osprofiler/blob/master/osprofiler/profiler.py#L59

So the previous base_id is reused for the new trace. When the trace details are retrieved from the profiler database by searching for the base_id, events from both first and second traces are returned.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/575793
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=2e2ef6a8d045c150116242a5b0bed635483fc7c8
Submitter: Zuul
Branch: master

commit 2e2ef6a8d045c150116242a5b0bed635483fc7c8
Author: Stuart Grace <email address hidden>
Date: Fri Jun 15 17:56:25 2018 +0100

    Delete profiler object when request completes

    When a request that is being profiled completes and the response is
    received, the middleware expires the profiling cookie. It also needs
    to delete the profiling object that holds the base_id UUID so a new
    base_id will be created for the next profile. Otherwise the same
    base_id is used for subsequent queries and they become merged togther
    in the database.

    Change-Id: I379cebfa2ed5282c96df0e255a8ba04c65a8523c
    Closes-Bug: #1777486
    Depends-On: https://review.openstack.org/578362