ensure remote tagger do not block when starting

[GustavoCaso]

What does this PR do?

Ensure the remote tagger do not block during the boot process of the application

Motivation

The function startTaggerStream was called twice. One in the Start function, and another time in the run function in a separate Go routine.

The problem is that if the first call to startTaggerStream inside the Start function is not able to connect to the server it will block the boot process forever. Since we already call startTaggerStream inside the run function on a separate goroutine and in a loop we can safely remove the call to startTaggerStream inside the Start function.

Code for the run function:

func (t *remoteTagger) run() {
	for {
		select {
		case <-t.telemetryTicker.C:
			t.store.collectTelemetry()
			continue
		case <-t.ctx.Done():
			return
		default:
		}

		if t.stream == nil {
			if err := t.startTaggerStream(noTimeout); err != nil {
				t.log.Warnf("error received trying to start stream with target %q: %s", t.options.Target, err)
				continue
			}
		}

		var response *pb.StreamTagsResponse
		err := grpcutil.DoWithTimeout(func() error {
			var err error
			response, err = t.stream.Recv()
			return err
		}, streamRecvTimeout)
		if err != nil {
			t.streamCancel()

			t.telemetryStore.ClientStreamErrors.Inc()

			// when Recv() returns an error, the stream is aborted
			// and the contents of our store are considered out of
			// sync and therefore no longer valid, so the tagger
			// can no longer be considered ready, and the stream
			// must be re-established.
			t.ready = false
			t.stream = nil

			t.log.Warnf("error received from remote tagger: %s", err)

			continue
		}

		t.telemetryStore.Receives.Inc()

		err = t.processResponse(response)
		if err != nil {
			t.log.Warnf("error processing event received from remote tagger: %s", err)
			continue
		}
	}
}

Describe how to test/QA your changes

Added naive unit tests that test the main thread is not blocked

Possible Drawbacks / Trade-offs

Additional Notes

[cit-pr-commenter]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 4c1d4f2f-9b6f-4436-a95a-d5019c0e916d

Baseline: 9972b9e
Comparison: e5c0f9e
Diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	quality_gate_idle_all_features	memory utilization	+1.36	[+1.22, +1.49]	1	Logs bounds checks dashboard
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+1.26	[+0.52, +1.99]	1	Logs
➖	file_to_blackhole_1000ms_latency_linear_load	egress throughput	+0.39	[-0.07, +0.84]	1	Logs
➖	basic_py_check	% cpu utilization	+0.31	[-3.57, +4.18]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	+0.23	[-0.56, +1.02]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	+0.07	[-0.63, +0.77]	1	Logs
➖	file_to_blackhole_300ms_latency	egress throughput	+0.04	[-0.59, +0.66]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	+0.00	[-0.11, +0.11]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.01, +0.01]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	-0.01	[-0.86, +0.84]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	-0.01	[-0.80, +0.77]	1	Logs
➖	otel_to_otel_logs	ingress throughput	-0.09	[-0.74, +0.57]	1	Logs
➖	file_tree	memory utilization	-0.80	[-0.94, -0.67]	1	Logs
➖	tcp_syslog_to_blackhole	ingress throughput	-0.82	[-0.89, -0.75]	1	Logs
➖	quality_gate_idle	memory utilization	-0.86	[-0.93, -0.80]	1	Logs bounds checks dashboard
➖	pycheck_lots_of_tags	% cpu utilization	-2.42	[-5.79, +0.95]	1	Logs

Bounds Checks: ❌ Failed

perf	experiment	bounds_check_name	replicates_passed	links
❌	file_to_blackhole_1000ms_latency	lost_bytes	0/10
✅	file_to_blackhole_0ms_latency	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency_linear_load	memory_usage	10/10
✅	file_to_blackhole_100ms_latency	lost_bytes	10/10
✅	file_to_blackhole_100ms_latency	memory_usage	10/10
✅	file_to_blackhole_300ms_latency	lost_bytes	10/10
✅	file_to_blackhole_300ms_latency	memory_usage	10/10
✅	file_to_blackhole_500ms_latency	lost_bytes	10/10
✅	file_to_blackhole_500ms_latency	memory_usage	10/10
✅	quality_gate_idle	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	bounds checks dashboard

Explanation

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.

[agent-platform-auto-pr]

Test changes on VM

Use this command from test-infra-definitions to manually test this PR changes on a VM:

inv create-vm --pipeline-id=49509634 --os-family=ubuntu

Note: This applies to commit e5c0f9e

[GustavoCaso]

/merge

[dd-devflow]

Devflow running: /merge

View all feedbacks in Devflow UI.

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2024-11-21 14:56:46 UTC ℹ️ MergeQueue: pull request added to the queue

The median merge time in main is 25m.