[CWS] Replace 64 bits trace ID by 128 bits for ebpf and ebpfless

[spikat]

What does this PR do?

It updates trace IDs to 128bits (as it's the new standard for the trace agent).

I've updated:

• the ebpf and ebpfless parts that retrieves the span/traces
• the syscall tester to push 128bit fake ids
• the functional tests now push 128bit fake ids
• I removed the encoding/decoding of spans/traces in activity dump processes as it make no sense to keep them
• I've also fixed a bug in newDDContextSerializer where we never use the spans/traces from ancestors (now it should be ok)

Also now, both span and trace ID are serialized to the backend as string (instead of uint64).
NB: span can be sent as decimal string but trace HAVE to be sent as LOWERCASE hexa, otherwise it wont work.

The java tracer has been updated too: DataDog/dd-trace-java#7259

Spans and traces maked as deprecated in activity dump proto in agent payload: DataDog/agent-payload#323

Motivation

Be compliant with the new dd tracer.

Additional Notes

• We can't use __int128 types in eBPF, otherwise it results in error when loading the program.
• For the syscall tester we use __int128, and for the agent we use the mathutil package for the Int128 type

Possible Drawbacks / Trade-offs

Describe how to test/QA your changes

Tests are passing with ebpf and ebpfless. You could play with syscalltester and with a traced java app

[cit-pr-commenter]

Go Package Import Differences

Baseline: 94c9e78
Comparison: 988c63f

binary	os	arch	change
cluster-agent	linux	amd64	+2, -0 +github.com/remyoudompheng/bigfft +modernc.org/mathutil
cluster-agent	linux	arm64	+2, -0 +github.com/remyoudompheng/bigfft +modernc.org/mathutil
system-probe	windows	amd64	+2, -0 +github.com/remyoudompheng/bigfft +modernc.org/mathutil

[pr-commenter]

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=40650360 --os-family=ubuntu

Note: This applies to commit 988c63f

[pr-commenter]

Regression Detector

Regression Detector Results

Run ID: 1477c9d4-7991-4c2b-ad93-ebd938d55558 Metrics dashboard Target profiles

Baseline: 94c9e78
Comparison: 988c63f

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

No significant changes in experiment optimization goals

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

There were no significant changes in experiment optimization goals at this confidence level and effect size tolerance.

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	links
➖	basic_py_check	% cpu utilization	+2.34	[-0.22, +4.90]	Logs
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+1.12	[+0.23, +2.02]	Logs
➖	tcp_syslog_to_blackhole	ingress throughput	+0.96	[-11.99, +13.91]	Logs
➖	file_tree	memory utilization	+0.16	[+0.09, +0.22]	Logs
➖	uds_dogstatsd_to_api	ingress throughput	+0.00	[-0.00, +0.00]	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.01, +0.01]	Logs
➖	otel_to_otel_logs	ingress throughput	-0.21	[-1.02, +0.60]	Logs
➖	idle	memory utilization	-0.76	[-0.80, -0.73]	Logs
➖	pycheck_1000_100byte_tags	% cpu utilization	-1.86	[-6.67, +2.95]	Logs

Explanation

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".

[maycmlee]

Nothing for docs to review.

[spikat]

/merge

[dd-devflow]

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[spikat]

/remove

[dd-devflow]

🚂 Devflow: /remove

[dd-devflow]

⚠️ MergeQueue: This merge request was unqueued

This merge request was unqueued

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[spikat]

/merge

[dd-devflow]

🚂 MergeQueue: pull request added to the queue

The median merge time in main is 23m.

Use /merge -c to cancel this operation!