chore(core): Wrap event metadata in Arc for performance

[bruceg]

The EventMetadata structure contains a number of sub-structures that can cause extensive deep copies when an event is cloned, most notably value: vrl::value::Value. To improve this, wrap the actual inner event metadata in an Arc, and use the standard tools from that type to only clone it when needed to provide a mutable or owned copy.

[bruceg]

/ci-run-regression

[datadog-vectordotdev]

Datadog Report

Branch report: bruceg/arc-event-metadata
Commit report: 8c540ec
Test service: vector

✅ 0 Failed, 7 Passed, 0 Skipped, 25.46s Total Time

[pront]

Very interesting PR!

/ci-run-regression

Did the above produce a report?

[jszwedko]

/ci-run-regression

[bruceg]

/ci-run-regression

[bruceg]

Did the above produce a report?

No. I'm wondering if it won't run on draft PRs, so I dropped the draft flag.

[github-actions]

Regression Detector Results

Run ID: 61034cca-2b3b-452a-87b7-b0b45b052989 Metrics dashboard

Baseline: 06ad674
Comparison: 32c4fd8

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

Significant changes in experiment optimization goals

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

perf	experiment	goal	Δ mean %	Δ mean % CI	links
✅	http_text_to_http_json	ingress throughput	+12.70	[+12.56, +12.84]
✅	syslog_log2metric_humio_metrics	ingress throughput	+11.19	[+11.07, +11.31]
✅	http_to_http_acks	ingress throughput	+7.22	[+6.06, +8.37]

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf	experiment	goal	Δ mean %	Δ mean % CI	links
➖	file_to_blackhole	egress throughput	-2.81	[-9.49, +3.88]

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	links
✅	http_text_to_http_json	ingress throughput	+12.70	[+12.56, +12.84]
✅	syslog_log2metric_humio_metrics	ingress throughput	+11.19	[+11.07, +11.31]
✅	http_to_http_acks	ingress throughput	+7.22	[+6.06, +8.37]
➖	fluent_elasticsearch	ingress throughput	+2.10	[+1.60, +2.60]
➖	socket_to_socket_blackhole	ingress throughput	+1.98	[+1.92, +2.04]
➖	datadog_agent_remap_datadog_logs_acks	ingress throughput	+1.68	[+1.49, +1.88]
➖	otlp_http_to_blackhole	ingress throughput	+1.67	[+1.56, +1.79]
➖	otlp_grpc_to_blackhole	ingress throughput	+1.66	[+1.55, +1.77]
➖	http_to_s3	ingress throughput	+1.26	[+0.99, +1.53]
➖	splunk_hec_route_s3	ingress throughput	+1.12	[+0.78, +1.46]
➖	syslog_loki	ingress throughput	+1.11	[+1.04, +1.18]
➖	datadog_agent_remap_blackhole	ingress throughput	+1.07	[+0.96, +1.17]
➖	syslog_log2metric_tag_cardinality_limit_blackhole	ingress throughput	+0.67	[+0.60, +0.75]
➖	datadog_agent_remap_datadog_logs	ingress throughput	+0.47	[+0.24, +0.70]
➖	syslog_humio_logs	ingress throughput	+0.46	[+0.31, +0.61]
➖	datadog_agent_remap_blackhole_acks	ingress throughput	+0.28	[+0.15, +0.42]
➖	http_to_http_noack	ingress throughput	+0.15	[+0.07, +0.23]
➖	syslog_log2metric_splunk_hec_metrics	ingress throughput	+0.08	[-0.02, +0.19]
➖	http_to_http_json	ingress throughput	+0.06	[+0.01, +0.11]
➖	http_elasticsearch	ingress throughput	+0.02	[-0.18, +0.22]
➖	splunk_hec_to_splunk_hec_logs_acks	ingress throughput	+0.01	[-0.08, +0.10]
➖	splunk_hec_to_splunk_hec_logs_noack	ingress throughput	+0.01	[-0.09, +0.10]
➖	splunk_hec_indexer_ack_blackhole	ingress throughput	+0.01	[-0.07, +0.09]
➖	syslog_regex_logs2metric_ddmetrics	ingress throughput	-1.15	[-1.28, -1.02]
➖	syslog_splunk_hec_logs	ingress throughput	-2.28	[-2.40, -2.15]
➖	file_to_blackhole	egress throughput	-2.81	[-9.49, +3.88]

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".

[jszwedko]

Did the above produce a report?

No. I'm wondering if it won't run on draft PRs, so I dropped the draft flag.

The trigger actually requires the comment to be left as a review now rather than simply a comment.

[bruceg]

Given that the entire inner metadata is now in an Arc, would it make sense to unwrap any of the inner Arc fields? Most likely not for the schema_definition, but what about the others?

[lukesteensen]

would it make sense to unwrap any of the inner Arc fields?

I'm skeptical that unwrapping these would make much of a difference. There may still be some slight benefit to keeping them wrapped if they are more static than other metadata fields.

[pront]

This needs a rebase (or merge) on the latest origin/master. Otherwise, it is good to go 🚀

[github-actions]

Regression Detector Results

Run ID: 8136f083-e23f-42de-aac8-09a138110872 Metrics dashboard

Baseline: 5d517b9
Comparison: 86c313f

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

Significant changes in experiment optimization goals

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

perf	experiment	goal	Δ mean %	Δ mean % CI	links
✅	http_text_to_http_json	ingress throughput	+13.70	[+13.53, +13.86]
✅	socket_to_socket_blackhole	ingress throughput	+6.23	[+6.17, +6.29]

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf	experiment	goal	Δ mean %	Δ mean % CI	links
➖	file_to_blackhole	egress throughput	-2.21	[-6.26, +1.84]

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	links
✅	http_text_to_http_json	ingress throughput	+13.70	[+13.53, +13.86]
✅	socket_to_socket_blackhole	ingress throughput	+6.23	[+6.17, +6.29]
➖	datadog_agent_remap_datadog_logs	ingress throughput	+3.81	[+3.64, +3.98]
➖	otlp_http_to_blackhole	ingress throughput	+2.71	[+2.62, +2.80]
➖	syslog_log2metric_humio_metrics	ingress throughput	+2.61	[+2.49, +2.74]
➖	http_elasticsearch	ingress throughput	+2.58	[+2.39, +2.76]
➖	syslog_log2metric_splunk_hec_metrics	ingress throughput	+1.23	[+1.10, +1.36]
➖	syslog_loki	ingress throughput	+1.03	[+0.94, +1.11]
➖	syslog_humio_logs	ingress throughput	+0.80	[+0.64, +0.95]
➖	datadog_agent_remap_blackhole	ingress throughput	+0.40	[+0.33, +0.48]
➖	datadog_agent_remap_datadog_logs_acks	ingress throughput	+0.23	[+0.10, +0.36]
➖	syslog_log2metric_tag_cardinality_limit_blackhole	ingress throughput	+0.16	[+0.05, +0.26]
➖	splunk_hec_to_splunk_hec_logs_noack	ingress throughput	+0.00	[-0.02, +0.02]
➖	splunk_hec_indexer_ack_blackhole	ingress throughput	-0.00	[-0.02, +0.02]
➖	http_to_http_noack	ingress throughput	-0.00	[-0.06, +0.06]
➖	splunk_hec_to_splunk_hec_logs_acks	ingress throughput	-0.00	[-0.03, +0.02]
➖	http_to_http_json	ingress throughput	-0.01	[-0.05, +0.04]
➖	http_to_s3	ingress throughput	-0.10	[-0.26, +0.06]
➖	datadog_agent_remap_blackhole_acks	ingress throughput	-0.14	[-0.25, -0.02]
➖	http_to_http_acks	ingress throughput	-0.75	[-1.21, -0.28]
➖	otlp_grpc_to_blackhole	ingress throughput	-1.23	[-1.42, -1.05]
➖	syslog_splunk_hec_logs	ingress throughput	-1.88	[-1.99, -1.76]
➖	file_to_blackhole	egress throughput	-2.21	[-6.26, +1.84]
➖	splunk_hec_route_s3	ingress throughput	-2.64	[-2.95, -2.33]
➖	syslog_regex_logs2metric_ddmetrics	ingress throughput	-3.04	[-3.15, -2.92]
➖	fluent_elasticsearch	ingress throughput	-3.35	[-3.89, -2.80]

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".