Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[EBPF] telemetry: clean maps before stopping the manager #32522

Open
wants to merge 3 commits into
base: main
Choose a base branch
from

Conversation

gjulianm
Copy link
Contributor

@gjulianm gjulianm commented Dec 26, 2024

What does this PR do?

This PR changes how the telemetry cleanup is done. Instead of relying on an extra call, we use the manager modifier BeforeStop method introduced in #32453 to automatically clean up without explicit calls. Cleanup for other structures the telemetry modifier created has also been added to that hook.

Motivation

Fix an error where GPU and USM modules could not start at the same time, as the shared-libraries program would not re-start due to some leftover data in the telemetry maps.

Describe how you validated your changes

Unit tests included.

Possible Drawbacks / Trade-offs

Additional Notes

@gjulianm gjulianm self-assigned this Dec 26, 2024
@gjulianm gjulianm added changelog/no-changelog qa/done QA done before merge and regressions are covered by tests labels Dec 26, 2024
@gjulianm gjulianm force-pushed the guillermo.julian/telemetry-before-stop branch from 057c6ed to a6d04c3 Compare December 26, 2024 12:39
@gjulianm gjulianm marked this pull request as ready for review December 26, 2024 12:39
@gjulianm gjulianm requested review from a team as code owners December 26, 2024 12:39
@gjulianm gjulianm requested a review from AyyLam December 26, 2024 12:40
@gjulianm gjulianm added the ask-review Ask required teams to review this PR label Dec 26, 2024
Copy link

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: b21f3dea-88c4-4236-a0df-5d685dd70ce3

Baseline: 409fc48
Comparison: a6d04c3
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_logs % cpu utilization +2.17 [-1.08, +5.42] 1 Logs
uds_dogstatsd_to_api_cpu % cpu utilization +0.54 [-0.14, +1.22] 1 Logs
tcp_syslog_to_blackhole ingress throughput +0.50 [+0.44, +0.57] 1 Logs
file_to_blackhole_1000ms_latency egress throughput +0.32 [-0.47, +1.10] 1 Logs
quality_gate_idle memory utilization +0.17 [+0.14, +0.21] 1 Logs bounds checks dashboard
file_to_blackhole_300ms_latency egress throughput +0.15 [-0.49, +0.79] 1 Logs
file_to_blackhole_1000ms_latency_linear_load egress throughput +0.13 [-0.35, +0.60] 1 Logs
file_to_blackhole_0ms_latency_http1 egress throughput +0.10 [-0.77, +0.97] 1 Logs
file_to_blackhole_500ms_latency egress throughput +0.09 [-0.69, +0.87] 1 Logs
file_to_blackhole_0ms_latency egress throughput +0.04 [-0.77, +0.84] 1 Logs
file_to_blackhole_0ms_latency_http2 egress throughput +0.02 [-0.86, +0.89] 1 Logs
tcp_dd_logs_filter_exclude ingress throughput -0.00 [-0.01, +0.01] 1 Logs
uds_dogstatsd_to_api ingress throughput -0.00 [-0.12, +0.11] 1 Logs
file_to_blackhole_100ms_latency egress throughput -0.01 [-0.73, +0.72] 1 Logs
file_tree memory utilization -0.36 [-0.48, -0.24] 1 Logs
quality_gate_idle_all_features memory utilization -0.66 [-0.74, -0.58] 1 Logs bounds checks dashboard

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:

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

Copy link
Contributor

@val06 val06 left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

reviewed

// Cleanup mapKeys (initialized in initializeMapErrTelemetryMap)
h := keyHash()
for _, mapName := range maps {
delete(e.mapKeys, mapTelemetryKey(mapName, mn))
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

why not just create a new empty map instead of deleting each element?
e.mapKeys = make(map[telemetryKey]uint64)

Comment on lines +135 to +137
if p.moduleName != mn {
continue
}
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

why this only present for the helper keys?

Comment on lines +156 to +158
if perfCollector != nil {
perfCollector.unregisterTelemetry(m)
}
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

do we really want to do it in the modifer BeforeStop? that feels very wrong design wise.
This should be handled by the ebpfErrorsTelemetry itself and not by the modifier

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

perfCollector is not even part of errors telemetry. This should definitely not be done here.

@@ -60,6 +60,7 @@ func (k *telemetryKey) String() string {
type ebpfErrorsTelemetry interface {
sync.Locker
fill([]names.MapName, names.ModuleName, *maps.GenericMap[uint64, mapErrTelemetry], *maps.GenericMap[uint64, helperErrTelemetry]) error
cleanup([]names.MapName, names.ModuleName, *maps.GenericMap[uint64, mapErrTelemetry], *maps.GenericMap[uint64, helperErrTelemetry]) error
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nit - it will be useful to document the functions and the parameters

// Unless explicitly stated otherwise all files in this repository are licensed
// under the Apache License Version 2.0.
// This product includes software developed at Datadog (https://www.datadoghq.com/).
// Copyright 2016-present Datadog, Inc.
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nit

Suggested change
// Copyright 2016-present Datadog, Inc.
// Copyright 2024-present Datadog, Inc.

Copy link
Contributor

@guyarb guyarb left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM for USM owned files

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
ask-review Ask required teams to review this PR changelog/no-changelog component/system-probe medium review PR review might take time qa/done QA done before merge and regressions are covered by tests team/ebpf-platform
Projects
None yet
Development

Successfully merging this pull request may close these issues.

4 participants