[exporter/awsemf] NaN values are not handled properly

[bryan-aguilar]

Component(s)

exporter/awsemf

What happened?

Description

Metrics with NaN values will cause EMF Exporter JSON Marshaling to fail. This will cause the entire EMF Log to be discarded along with any other metrics it contains. This is not a desirable behavior and EMF Exporter should handle NaN values gracefully. Cloudwatch EMF does not support NaN values.

I would suggest as solution that metrics with a NaN value are dropped.

Steps to Reproduce

Scrape a prometheus endpoint that exports a NaN Value

Here is a unit test to confirm that an error is thrown during JSON Marshalling. This test belongs in emf_exporter_test.go

    func TestConsumeMetricsWithOutputDestinationNaN(t *testing.T) {
    	ctx, cancel := context.WithCancel(context.Background())
    	defer cancel()
    	factory := NewFactory()
    	expCfg := factory.CreateDefaultConfig().(*Config)
    	expCfg.Region = "us-west-2"
    	expCfg.MaxRetries = 0
    	expCfg.OutputDestination = "stdout"
    	exp, err := newEmfExporter(expCfg, exportertest.NewNopCreateSettings())
    	assert.Nil(t, err)
    	assert.NotNil(t, exp)
     
    	md := generateTestMetrics(testMetric{
    		metricNames:  []string{"metric_1"},
    		metricValues: [][]float64{{math.NaN()}},
    	})
    	require.NoError(t, exp.pushMetricsData(ctx, md))
    	require.NoError(t, exp.shutdown(ctx))
    }

Expected Result

All valid metrics are exported in EMF log.

Actual Result

Entire EMF log is discareded.

Collector version

v0.83.0

Environment information

Environment

OS: (e.g., "Ubuntu 20.04")
Compiler(if manually compiled): (e.g., "go 14.2")

OpenTelemetry Collector configuration

No response

Log output

No response

Additional context

No response

[bryan-aguilar]

I'm going to take a stab at this today.