mix_histogram_over_time.test

# Tests illustrating a bug where histogram samples are incorrectly discarded as out-of-order
# when a load directive contains a single series that combines float and histogram samples
# ( https://github.com/prometheus/prometheus/pull/17021 )
#
# Place in promql/promqltest/testdata/mix_histogram_over_time.test
#
# Run from prometheus source code root dir with
#
#     go test -v -run 'TestEvaluations/testdata/mix_histogram_over_time.test' ./promql
#
# 

load 10s
    data_histogram{type="mix_histfirst"} {{schema:0 sum:1 count:2}} {{schema:0 sum:2 count:3}} 0 1

# Test result matching for this will fail with a complaint:
#
#    error in eval count_over_time(data_histogram[2m]) (line 8): expected 4 for {type="mix_histfirst"} but got 2
#
# because the two histogram samples got discarded silently as out-of-order.
eval instant at 1m count_over_time(data_histogram[2m])
    expect no_info
    expect no_warn
    {type="mix_histfirst"} 4

clear


# To work around this bug in the appender (which probably really only affects
# the test suite in practice), load histogram samples alone as the first
# samples in the series:

load 10s
    data_histogram{type="mix_histfirst"} {{schema:0 sum:1 count:2}} {{schema:0 sum:2 count:3}}

# then append some float samples in a separate transaction. This must be a separate load directive
# to ensure the appender is committed, so the histogram samples are not falsely rejected as
# out-of-order vis-a-vis the float samples.
load 10s
    data_histogram{type="mix_histfirst"} _ _ 0 1

# As a result, this test will pass
eval instant at 1m count_over_time(data_histogram[2m])
    expect no_warn
    expect no_info
    {type="mix_histfirst"} 4

clear

test-output.txt

# output of go test -v -run 'TestEvaluations/testdata/mix_histogram_over_time.test' ./promql
# annotated

=== RUN   TestEvaluations
=== RUN   TestEvaluations/testdata/mix_histogram_over_time.test
=== RUN   TestEvaluations/testdata/mix_histogram_over_time.test/line_13/count_over_time(data_histogram[2m])
    test.go:1321: 
        	Error Trace:	/home/craig/upm/upm-stack/prometheus/promql/promqltest/test.go:1321
        	Error:      	Received unexpected error:
        	            	error in eval count_over_time(data_histogram[2m]) (line 13): expected 4 for {type="mix_histfirst"} but got 2
        	Test:       	TestEvaluations/testdata/mix_histogram_over_time.test/line_13/count_over_time(data_histogram[2m])
=== RUN   TestEvaluations/testdata/mix_histogram_over_time.test/line_35/count_over_time(data_histogram[2m])
--- FAIL: TestEvaluations (0.06s)
    --- FAIL: TestEvaluations/testdata/mix_histogram_over_time.test (0.06s)
        # **** this fails because of the load dropping the histogram samples ****
        --- FAIL: TestEvaluations/testdata/mix_histogram_over_time.test/line_13/count_over_time(data_histogram[2m]) (0.00s)
        # **** then the repeat run with the workaround split load passes ****
        --- PASS: TestEvaluations/testdata/mix_histogram_over_time.test/line_35/count_over_time(data_histogram[2m]) (0.00s)
FAIL
FAIL	github.com/prometheus/prometheus/promql	0.072s
FAIL