[perfmon] Fix typo in variable name

[gthvn1]

No description provided.

[psafont]

@gthvn1 Tests are failing because perfmon doesn't have any tests. This means that currently perfmon can't be modified without spending the effort to add them

[gthvn1]

Oh. I understood that python3/tests/test_extauth_hook_AD.py and nbd_client_manager:nbd_client_manager.py failed. So it was not related to my modification. And I see the coverage issue but I thought it was only a warning.
Ok so I guess that need to have a closer look to understand how to add a test ;)

[gthvn1]

In fact I see in the logs:

...
python3/tests/test_perfmon.py::TestGetFsUsage::test_get_percent_fs_usage PASSED [ 40%]
python3/tests/test_perfmon.py::TestGetFsUsage::test_get_percent_log_fs_usage PASSED [ 41%]
python3/tests/test_perfmon.py::TestGetFsUsage::test_get_percent_log_fs_usage_same_file_system PASSED [ 42%]
python3/tests/test_perfmon.py::TestGetMemUsage::test_get_percent_mem_usage PASSED [ 43%]
python3/tests/test_perfmon.py::TestGetMemUsage::test_get_percent_mem_usage_exception PASSED [ 43%]
python3/tests/test_perfmon.py::TestGetPercentSRUsage::test_get_percent_sr_usage_correct_input PASSED [ 44%]
python3/tests/test_perfmon.py::TestGetPercentSRUsage::test_get_percent_sr_usage_exception_handling PASSED [ 45%]
...

So it looks like perfmon has some tests.
But when I run tests locally (I just run pytest tests) I have an issue with tests/observer/it_traces.py.

>           assert span.__name__ == "span_of_tracers"
E           AssertionError: assert '_span_noop' == 'span_of_tracers'
E
E             - span_of_tracers
E             + _span_noop

tests/observer/it_traces.py:73: AssertionError
---------------------------------------------------------------------------------------------- Captured stdout call ----------------------------------------------------------------------------------------------
Hello, I am a print() in traced_script.py.
----------------------------------------------------------------------------------------------- Captured log call ------------------------------------------------------------------------------------------------
DEBUG    __main__:observer.py:400 configs = ['/home/gthouvenin/git/xen-api/python3/tests/observer/observer.conf']
ERROR    __main__:observer.py:147 missing opentelemetry dependencies: No module named 'opentelemetry'
============================================================================================ short test summary info =============================================================================================
FAILED tests/observer/it_traces.py::it_creates_a_tracer - AssertionError: assert '_span_noop' == 'span_of_tracers'
========================================================================================= 1 failed, 109 passed in 0.32s ==========================================================================================

[lindig]

@snwoods is there anything related to tracing that could be outdated above?

[snwoods]

The issue with the tests/observer/it_traces.py test is that you don't have the opentelemetry python module installed. The output shows missing opentelemetry dependencies which happens when there is an import error. It then falls back to the _span_noop function decorator, which is to say tracing is disabled. But the test expects span_of_tracers decorator function