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AGNTLOG-2 - reduce payload memory usage in the logs pipeline#35351

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dd-mergequeue[bot] merged 1 commit intomainfrom
ryan.hall/reduce-log-payload-size
Mar 24, 2025
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AGNTLOG-2 - reduce payload memory usage in the logs pipeline#35351
dd-mergequeue[bot] merged 1 commit intomainfrom
ryan.hall/reduce-log-payload-size

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@ddrthall ddrthall commented Mar 21, 2025

What does this PR do?

The logs payload entity stores metadata for all of the respective messages batched within, but also stores the message contents themselves. This isn't required, all consumers of the logs payload will interact with the encoded bytes buffer rather than the raw contents. Additionally, dropping these message contents on payload construction can save considerable amounts of RSS memory for log agents experiencing enough load to buffer multiple payloads.

This PR shallow copies the message metadata into each payload, rather than injecting the whole message entity.

Motivation

Describe how you validated your changes

Validation was completed by a combination of 1. unit test additions, 2. successful code compilation, 3. SMP performance runs

Possible Drawbacks / Trade-offs

Adding memory allocation in the critical path (for the metadata shallow copy) isn't ideal, but given we're already allocating a new array for the entirety of the contents in the same code path its impact shouldn't be noticeable.

Additional Notes

The memory savings for a system under heavy load is extreme. Attached is the memory comparison used in the file_to_blackhole_1000ms_latency_linear_load regression test:
Screenshot 2025-03-21 at 11 25 17 AM

@github-actions github-actions bot added long review PR is complex, plan time to review it team/agent-log-pipelines labels Mar 21, 2025
@ddrthall ddrthall added this to the 7.66.0 milestone Mar 21, 2025
@ddrthall ddrthall added the qa/done QA done before merge and regressions are covered by tests label Mar 21, 2025
@ddrthall ddrthall force-pushed the ryan.hall/reduce-log-payload-size branch from fe1b36c to 1156c5f Compare March 21, 2025 13:37
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agent-platform-auto-pr bot commented Mar 21, 2025

Uncompressed package size comparison

Comparison with ancestor 7e6f8979b1de82c9bd705fddde36faf64617b476

Diff per package
package diff status size ancestor threshold
datadog-agent-amd64-deb 0.02MB ⚠️ 806.46MB 806.45MB 0.50MB
datadog-agent-x86_64-rpm 0.02MB ⚠️ 816.27MB 816.25MB 0.50MB
datadog-agent-x86_64-suse 0.02MB ⚠️ 816.27MB 816.25MB 0.50MB
datadog-agent-arm64-deb 0.02MB ⚠️ 797.53MB 797.52MB 0.50MB
datadog-agent-aarch64-rpm 0.02MB ⚠️ 807.32MB 807.31MB 0.50MB
datadog-heroku-agent-amd64-deb 0.01MB ⚠️ 441.91MB 441.90MB 0.50MB
datadog-dogstatsd-amd64-deb 0.00MB 39.36MB 39.35MB 0.50MB
datadog-dogstatsd-x86_64-rpm 0.00MB 39.44MB 39.43MB 0.50MB
datadog-dogstatsd-x86_64-suse 0.00MB 39.44MB 39.43MB 0.50MB
datadog-dogstatsd-arm64-deb 0.00MB 37.88MB 37.88MB 0.50MB
datadog-iot-agent-arm64-deb 0.00MB 58.30MB 58.29MB 0.50MB
datadog-iot-agent-aarch64-rpm 0.00MB 58.37MB 58.37MB 0.50MB
datadog-iot-agent-amd64-deb 0.00MB 61.00MB 61.00MB 0.50MB
datadog-iot-agent-x86_64-rpm 0.00MB 61.07MB 61.07MB 0.50MB
datadog-iot-agent-x86_64-suse 0.00MB 61.07MB 61.07MB 0.50MB

Decision

⚠️ Warning

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agent-platform-auto-pr bot commented Mar 21, 2025

Test changes on VM

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

dda inv aws.create-vm --pipeline-id=59624210 --os-family=ubuntu

Note: This applies to commit 530586f

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agent-platform-auto-pr bot commented Mar 21, 2025

Static quality checks ✅

Please find below the results from static quality gates

Successful checks

Info

Result Quality gate On disk size On disk size limit On wire size On wire size limit
static_quality_gate_agent_deb_amd64 780.73 MiB 801.8 MiB 190.57 MiB 202.62 MiB
static_quality_gate_agent_deb_arm64 772.17 MiB 793.14 MiB 172.69 MiB 184.51 MiB
static_quality_gate_agent_rpm_amd64 780.73 MiB 801.79 MiB 193.18 MiB 205.03 MiB
static_quality_gate_agent_rpm_arm64 772.18 MiB 793.09 MiB 174.18 MiB 186.44 MiB
static_quality_gate_agent_suse_amd64 780.72 MiB 801.81 MiB 193.18 MiB 205.03 MiB
static_quality_gate_agent_suse_arm64 772.17 MiB 793.14 MiB 174.18 MiB 186.44 MiB
static_quality_gate_dogstatsd_deb_amd64 37.61 MiB 47.67 MiB 9.75 MiB 19.78 MiB
static_quality_gate_dogstatsd_deb_arm64 36.2 MiB 46.27 MiB 8.45 MiB 18.49 MiB
static_quality_gate_dogstatsd_rpm_amd64 37.61 MiB 47.67 MiB 9.76 MiB 19.79 MiB
static_quality_gate_dogstatsd_suse_amd64 37.61 MiB 47.67 MiB 9.76 MiB 19.79 MiB
static_quality_gate_iot_agent_deb_amd64 58.25 MiB 69.0 MiB 14.71 MiB 24.8 MiB
static_quality_gate_iot_agent_deb_arm64 55.68 MiB 66.4 MiB 12.72 MiB 22.8 MiB
static_quality_gate_iot_agent_rpm_amd64 58.25 MiB 69.0 MiB 14.73 MiB 24.8 MiB
static_quality_gate_iot_agent_rpm_arm64 55.68 MiB 66.4 MiB 12.74 MiB 22.8 MiB
static_quality_gate_iot_agent_suse_amd64 58.25 MiB 69.0 MiB 14.73 MiB 24.8 MiB
static_quality_gate_docker_agent_amd64 865.27 MiB 886.12 MiB 291.18 MiB 304.21 MiB
static_quality_gate_docker_agent_arm64 880.01 MiB 900.79 MiB 277.64 MiB 290.47 MiB
static_quality_gate_docker_agent_jmx_amd64 1.04 GiB 1.06 GiB 366.28 MiB 379.33 MiB
static_quality_gate_docker_agent_jmx_arm64 1.04 GiB 1.06 GiB 348.74 MiB 361.55 MiB
static_quality_gate_docker_dogstatsd_amd64 45.75 MiB 55.78 MiB 17.26 MiB 27.28 MiB
static_quality_gate_docker_dogstatsd_arm64 44.38 MiB 54.45 MiB 16.13 MiB 26.16 MiB
static_quality_gate_docker_cluster_agent_amd64 262.62 MiB 274.78 MiB 105.46 MiB 116.28 MiB
static_quality_gate_docker_cluster_agent_arm64 278.59 MiB 290.82 MiB 100.31 MiB 111.12 MiB

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cit-pr-commenter bot commented Mar 21, 2025

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 0c36866a-9506-49c9-86e9-63e83adf2d2c

Baseline: 7e6f897
Comparison: 530586f
Diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

perf experiment goal Δ mean % Δ mean % CI trials links
uds_dogstatsd_to_api_cpu % cpu utilization +0.87 [+0.06, +1.68] 1 Logs
file_to_blackhole_1000ms_latency egress throughput +0.08 [-0.69, +0.86] 1 Logs
quality_gate_logs % cpu utilization +0.06 [-2.71, +2.83] 1 Logs
file_to_blackhole_100ms_latency egress throughput +0.02 [-0.66, +0.69] 1 Logs
file_to_blackhole_0ms_latency_http1 egress throughput +0.01 [-0.79, +0.82] 1 Logs
tcp_dd_logs_filter_exclude ingress throughput -0.00 [-0.03, +0.02] 1 Logs
file_to_blackhole_0ms_latency egress throughput -0.01 [-0.81, +0.79] 1 Logs
file_to_blackhole_300ms_latency egress throughput -0.01 [-0.64, +0.62] 1 Logs
uds_dogstatsd_to_api ingress throughput -0.01 [-0.30, +0.28] 1 Logs
file_to_blackhole_0ms_latency_http2 egress throughput -0.02 [-0.79, +0.76] 1 Logs
file_tree memory utilization -0.05 [-0.18, +0.09] 1 Logs
file_to_blackhole_1000ms_latency_linear_load egress throughput -0.05 [-0.51, +0.41] 1 Logs
file_to_blackhole_500ms_latency egress throughput -0.09 [-0.87, +0.69] 1 Logs
uds_dogstatsd_20mb_12k_contexts_20_senders memory utilization -0.28 [-0.34, -0.22] 1 Logs
quality_gate_idle memory utilization -0.87 [-0.95, -0.78] 1 Logs bounds checks dashboard
quality_gate_idle_all_features memory utilization -1.63 [-1.75, -1.50] 1 Logs bounds checks dashboard
tcp_syslog_to_blackhole ingress throughput -2.62 [-2.67, -2.56] 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 intake_connections 10/10 bounds checks dashboard
quality_gate_idle memory_usage 10/10 bounds checks dashboard
quality_gate_idle_all_features intake_connections 10/10 bounds checks dashboard
quality_gate_idle_all_features memory_usage 10/10 bounds checks dashboard
quality_gate_logs intake_connections 10/10
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_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
  • quality_gate_idle, bounds check intake_connections: 10/10 replicas passed. Gate passed.
  • quality_gate_idle_all_features, bounds check intake_connections: 10/10 replicas passed. Gate passed.
  • quality_gate_idle_all_features, 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_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
  • quality_gate_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.

@ddrthall ddrthall force-pushed the ryan.hall/reduce-log-payload-size branch 3 times, most recently from 2866296 to f3b2642 Compare March 21, 2025 17:08
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Static quality checks ❌

Please find below the results from static quality gates

Error

Result Quality gate On disk size On disk size limit On wire size On wire size limit
static_quality_gate_docker_dogstatsd_arm64 DataNotFound 54.45 MiB DataNotFound 26.16 MiB
static_quality_gate_docker_cluster_agent_amd64 DataNotFound 274.78 MiB DataNotFound 116.28 MiB
Gate failure full details
Quality gate Error type Error message
static_quality_gate_docker_dogstatsd_arm64 StackTrace Traceback (most recent call last):
File "/go/src/github.com/DataDog/datadog-agent/tasks/quality_gates.py", line 124, in parse_and_trigger_gates
gate_mod.entrypoint(**gate_inputs)
File "/go/src/github.com/DataDog/datadog-agent/tasks/static_quality_gates/static_quality_gate_docker_dogstatsd_arm64.py", line 5, in entrypoint
generic_docker_agent_quality_gate(
File "/go/src/github.com/DataDog/datadog-agent/tasks/static_quality_gates/lib/docker_agent_lib.py", line 103, in generic_docker_agent_quality_gate
image_on_wire_size, image_on_disk_size = get_image_url_size(ctx, metric_handler, gate_name, url)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/go/src/github.com/DataDog/datadog-agent/tasks/static_quality_gates/lib/docker_agent_lib.py", line 40, in get_image_url_size
image_on_wire_size = int(image_on_wire_size.stdout)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ValueError: invalid literal for int() with base 10: '\n'
static_quality_gate_docker_cluster_agent_amd64 StackTrace Traceback (most recent call last):
File "/go/src/github.com/DataDog/datadog-agent/tasks/quality_gates.py", line 124, in parse_and_trigger_gates
gate_mod.entrypoint(**gate_inputs)
File "/go/src/github.com/DataDog/datadog-agent/tasks/static_quality_gates/static_quality_gate_docker_cluster_agent_amd64.py", line 5, in entrypoint
generic_docker_agent_quality_gate(
File "/go/src/github.com/DataDog/datadog-agent/tasks/static_quality_gates/lib/docker_agent_lib.py", line 103, in generic_docker_agent_quality_gate
image_on_wire_size, image_on_disk_size = get_image_url_size(ctx, metric_handler, gate_name, url)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/go/src/github.com/DataDog/datadog-agent/tasks/static_quality_gates/lib/docker_agent_lib.py", line 40, in get_image_url_size
image_on_wire_size = int(image_on_wire_size.stdout)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ValueError: invalid literal for int() with base 10: '\n'
Successful checks

Info

Result Quality gate On disk size On disk size limit On wire size On wire size limit
static_quality_gate_agent_deb_amd64 780.71 MiB 801.8 MiB 190.56 MiB 202.62 MiB
static_quality_gate_agent_deb_arm64 772.19 MiB 793.14 MiB 172.76 MiB 184.51 MiB
static_quality_gate_agent_rpm_amd64 780.74 MiB 801.79 MiB 193.19 MiB 205.03 MiB
static_quality_gate_agent_rpm_arm64 772.14 MiB 793.09 MiB 174.13 MiB 186.44 MiB
static_quality_gate_agent_suse_amd64 780.72 MiB 801.81 MiB 193.19 MiB 205.03 MiB
static_quality_gate_agent_suse_arm64 772.18 MiB 793.14 MiB 174.13 MiB 186.44 MiB
static_quality_gate_dogstatsd_deb_amd64 37.61 MiB 47.67 MiB 9.75 MiB 19.78 MiB
static_quality_gate_dogstatsd_deb_arm64 36.2 MiB 46.27 MiB 8.45 MiB 18.49 MiB
static_quality_gate_dogstatsd_rpm_amd64 37.61 MiB 47.67 MiB 9.76 MiB 19.79 MiB
static_quality_gate_dogstatsd_suse_amd64 37.61 MiB 47.67 MiB 9.76 MiB 19.79 MiB
static_quality_gate_iot_agent_deb_amd64 58.25 MiB 69.0 MiB 14.71 MiB 24.8 MiB
static_quality_gate_iot_agent_deb_arm64 55.68 MiB 66.4 MiB 12.71 MiB 22.8 MiB
static_quality_gate_iot_agent_rpm_amd64 58.25 MiB 69.0 MiB 14.73 MiB 24.8 MiB
static_quality_gate_iot_agent_rpm_arm64 55.68 MiB 66.4 MiB 12.74 MiB 22.8 MiB
static_quality_gate_iot_agent_suse_amd64 58.25 MiB 69.0 MiB 14.73 MiB 24.8 MiB
static_quality_gate_docker_agent_amd64 865.27 MiB 886.12 MiB 291.18 MiB 304.21 MiB
static_quality_gate_docker_agent_arm64 880.01 MiB 900.79 MiB 277.64 MiB 290.47 MiB
static_quality_gate_docker_agent_jmx_amd64 1.04 GiB 1.06 GiB 366.29 MiB 379.33 MiB
static_quality_gate_docker_agent_jmx_arm64 1.04 GiB 1.06 GiB 348.73 MiB 361.55 MiB
static_quality_gate_docker_dogstatsd_amd64 45.75 MiB 55.78 MiB 17.26 MiB 27.28 MiB
static_quality_gate_docker_cluster_agent_arm64 278.59 MiB 290.82 MiB 100.31 MiB 111.12 MiB

@ddrthall ddrthall marked this pull request as ready for review March 21, 2025 19:05
@ddrthall ddrthall requested review from a team as code owners March 21, 2025 19:05
func NewPayload(messages []*Message, encoded []byte, encoding string, unencodedSize int) *Payload {
messageMetas := make([]*MessageMetadata, len(messages))
for i, m := range messages {
// Split the metadata from the message content to avoid holding the entire message in memory
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👏 🥳

message := NewMessage(content, nil, "", 2)

// Set up finalizer to track when content is GC'd
runtime.SetFinalizer(&message.content, trackGC)
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This is a cool test.
This seems like a nice way to assert memory behaviors in unit tests and possibly prevent memory regressions in the future 👍

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/merge

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dd-devflow bot commented Mar 24, 2025

View all feedbacks in Devflow UI.
2025-03-24 13:51:05 UTC ℹ️ Start processing command /merge


2025-03-24 13:51:15 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in main is approximately 2h (p90).


2025-03-24 14:27:48 UTC ℹ️ MergeQueue: This merge request was merged

@dd-mergequeue dd-mergequeue bot merged commit d09138c into main Mar 24, 2025
241 checks passed
@dd-mergequeue dd-mergequeue bot deleted the ryan.hall/reduce-log-payload-size branch March 24, 2025 14:27
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