[CONTP-545] quit leader election if context was cancelled #32331

adel121 · 2024-12-18T11:21:38Z

What does this PR do?

This PR ensures that the go routine running leader election is properly stopped when the main cluster agent context is cancelled.

Motivation

Avoid go routine leaks.

Describe how you validated your changes

Unit tests and E2E are sufficient.

But for extra validation, you can do the following QA:

Deploy the DCA with multiple replicas with leader election enabled.

Once a leader is elected, kill the leader, and ensure that a new leader is elected.

Example:

datadog:
  apiKeyExistingSecret: datadog-secret
  appKeyExistingSecret: datadog-secret
  logLevel: DEBUG
  kubelet:
    tlsVerify: false

clusterAgent:
  enabled: true
  replicas: 3

Wait for a leader to be elected:

From agent status on any dca instance:

===============
Leader Election
===============
  Leader Election Status:  Running
  Leader Name is: datadog-agent-cluster-agent-6f4947f5b5-n462j
  Last Acquisition of the lease: Wed, 18 Dec 2024 11:26:28 UTC
  Renewed leadership: Wed, 18 Dec 2024 11:26:58 UTC
  Number of leader transitions: 5 transitions

Kill the leader:

kubectl delete pod  datadog-agent-cluster-agent-6f4947f5b5-n462j

Ensure that a new leader is finally elected:

===============
Leader Election
===============
  Leader Election Status:  Running
  Leader Name is: datadog-agent-cluster-agent-6f4947f5b5-ngxtw
  Last Acquisition of the lease: Wed, 18 Dec 2024 11:29:06 UTC
  Renewed leadership: Wed, 18 Dec 2024 11:29:06 UTC
  Number of leader transitions: 6 transitions

Possible Drawbacks / Trade-offs

None

Additional Notes

None

adel121 · 2024-12-18T11:23:24Z

pkg/util/kubernetes/apiserver/leaderelection/leaderelection.go

+			return
+		default:
+			log.Infof("Starting leader election process for %q...", le.HolderIdentity)
+			le.leaderElector.Run(le.ctx)


The Run method of the leader elector is blocking, and will terminate if ctx was cancelled OR if the current instance lost leadership.

In case we lost leadership, we should call Run again to participate in the leader election process.

However, if the context was cancelled, we should just quit.

From the documentation:

Run will not return before leader election loop is stopped by ctx or it has stopped holding the leader lease

agent-platform-auto-pr · 2024-12-18T11:46:25Z

Uncompressed package size comparison

Comparison with ancestor 332025d2eca869ea264ad9abde503853757d5f70

Diff per package

package	diff	status	size	ancestor	threshold
datadog-dogstatsd-amd64-deb	0.00MB	✅	78.58MB	78.58MB	10.00MB
datadog-dogstatsd-x86_64-rpm	0.00MB	✅	78.65MB	78.65MB	10.00MB
datadog-dogstatsd-x86_64-suse	0.00MB	✅	78.65MB	78.65MB	10.00MB
datadog-dogstatsd-arm64-deb	0.00MB	✅	55.78MB	55.78MB	10.00MB
datadog-heroku-agent-amd64-deb	0.00MB	✅	505.04MB	505.04MB	70.00MB
datadog-iot-agent-amd64-deb	0.00MB	✅	113.30MB	113.30MB	10.00MB
datadog-iot-agent-x86_64-rpm	0.00MB	✅	113.37MB	113.37MB	10.00MB
datadog-iot-agent-x86_64-suse	0.00MB	✅	113.37MB	113.37MB	10.00MB
datadog-iot-agent-arm64-deb	0.00MB	✅	108.77MB	108.77MB	10.00MB
datadog-iot-agent-aarch64-rpm	0.00MB	✅	108.84MB	108.84MB	10.00MB
datadog-agent-x86_64-rpm	-0.01MB	✅	1196.98MB	1196.99MB	140.00MB
datadog-agent-x86_64-suse	-0.01MB	✅	1196.98MB	1196.99MB	140.00MB
datadog-agent-amd64-deb	-0.01MB	✅	1187.74MB	1187.76MB	140.00MB
datadog-agent-aarch64-rpm	-0.02MB	✅	942.97MB	942.99MB	140.00MB
datadog-agent-arm64-deb	-0.02MB	✅	933.75MB	933.77MB	140.00MB

Decision

✅ Passed

agent-platform-auto-pr · 2024-12-18T11:46:46Z

Test changes on VM

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

inv aws.create-vm --pipeline-id=51428482 --os-family=ubuntu

Note: This applies to commit 364ceb6

cit-pr-commenter · 2024-12-18T12:14:23Z

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 69b5801c-4333-4204-bfca-46f58f298140

Baseline: 332025d
Comparison: 364ceb6
Diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	tcp_syslog_to_blackhole	ingress throughput	+0.71	[+0.64, +0.78]	1	Logs
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+0.54	[-0.18, +1.26]	1	Logs
➖	otel_to_otel_logs	ingress throughput	+0.30	[-0.36, +0.97]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	+0.10	[-0.68, +0.88]	1	Logs
➖	file_to_blackhole_300ms_latency	egress throughput	+0.08	[-0.55, +0.72]	1	Logs
➖	quality_gate_idle	memory utilization	+0.07	[+0.04, +0.11]	1	Logs bounds checks dashboard
➖	file_tree	memory utilization	+0.04	[-0.09, +0.18]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	+0.03	[-0.71, +0.78]	1	Logs
➖	file_to_blackhole_1000ms_latency_linear_load	egress throughput	+0.03	[-0.44, +0.50]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	+0.02	[-0.88, +0.93]	1	Logs
➖	file_to_blackhole_0ms_latency_http2	egress throughput	+0.00	[-0.95, +0.95]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	+0.00	[-0.01, +0.01]	1	Logs
➖	file_to_blackhole_0ms_latency_http1	egress throughput	+0.00	[-0.90, +0.90]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.02	[-0.10, +0.07]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	-0.62	[-0.74, -0.51]	1	Logs bounds checks dashboard
➖	quality_gate_logs	% cpu utilization	-0.74	[-3.67, +2.19]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	-0.87	[-1.64, -0.09]	1	Logs

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	links
✅	file_to_blackhole_0ms_latency	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_0ms_latency_http1	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency_http1	memory_usage	10/10
✅	file_to_blackhole_0ms_latency_http2	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency_http2	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
✅	quality_gate_logs	lost_bytes	10/10
✅	quality_gate_logs	memory_usage	10/10

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:

Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.
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.
Its configuration does not mark it "erratic".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

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

adel121 · 2024-12-18T13:16:01Z

/merge

dd-devflow · 2024-12-18T13:16:11Z

Devflow running: `/merge`

View all feedbacks in Devflow UI.

2024-12-18 13:16:10 UTC ℹ️ MergeQueue: pull request added to the queue

The median merge time in main is 29m.

2024-12-18 13:36:19 UTC ℹ️ MergeQueue: This merge request was merged

quit leader election if context was cancelled

364ceb6

adel121 added kind/enhancement changelog/no-changelog component/cluster-agent team/container-platform The Container Platform Team qa/rc-required Only for a PR that requires validation on the Release Candidate labels Dec 18, 2024

adel121 added this to the 7.62.0 milestone Dec 18, 2024

github-actions bot added the short review PR is simple enough to be reviewed quickly label Dec 18, 2024

adel121 commented Dec 18, 2024

View reviewed changes

github-actions bot added medium review PR review might take time and removed short review PR is simple enough to be reviewed quickly labels Dec 18, 2024

adel121 marked this pull request as ready for review December 18, 2024 11:29

adel121 requested review from a team as code owners December 18, 2024 11:29

aureleoules approved these changes Dec 18, 2024

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wdhif approved these changes Dec 18, 2024

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clamoriniere approved these changes Dec 18, 2024

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dd-mergequeue bot merged commit f5e9ae4 into main Dec 18, 2024
284 checks passed

dd-mergequeue bot deleted the adelhajhassan/quit_leaderelection_if_context_was_cancelled branch December 18, 2024 13:36

adel121 changed the title ~~quit leader election if context was cancelled~~ [CONTP-545] quit leader election if context was cancelled Dec 23, 2024

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[CONTP-545] quit leader election if context was cancelled #32331

[CONTP-545] quit leader election if context was cancelled #32331

adel121 commented Dec 18, 2024 •

edited

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adel121 Dec 18, 2024

agent-platform-auto-pr bot commented Dec 18, 2024

agent-platform-auto-pr bot commented Dec 18, 2024

cit-pr-commenter bot commented Dec 18, 2024

Fine details of change detection per experiment

Bounds Checks: ✅ Passed

Explanation

adel121 commented Dec 18, 2024

dd-devflow bot commented Dec 18, 2024 •

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[CONTP-545] quit leader election if context was cancelled #32331

[CONTP-545] quit leader election if context was cancelled #32331

Conversation

adel121 commented Dec 18, 2024 • edited Loading

What does this PR do?

Motivation

Describe how you validated your changes

Possible Drawbacks / Trade-offs

Additional Notes

adel121 Dec 18, 2024

Choose a reason for hiding this comment

adel121 Dec 18, 2024

Choose a reason for hiding this comment

agent-platform-auto-pr bot commented Dec 18, 2024

Uncompressed package size comparison

Decision

agent-platform-auto-pr bot commented Dec 18, 2024

Test changes on VM

cit-pr-commenter bot commented Dec 18, 2024

Regression Detector

Regression Detector Results

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

Bounds Checks: ✅ Passed

Explanation

CI Pass/Fail Decision

adel121 commented Dec 18, 2024

dd-devflow bot commented Dec 18, 2024 • edited Loading

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adel121 commented Dec 18, 2024 •

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