Protocol v1 by AlexeyKuznetsov-DD · Pull Request #10801 · DataDog/dd-trace-java

AlexeyKuznetsov-DD · 2026-03-10T23:38:05Z

What Does This Do

Implements support for the Datadog Agent Trace Protocol v1.0 (v1.0/traces endpoint) in the Java tracer.
Introduces TraceMapperV1, a new serializer that encodes traces in the v1 msgpack format with a flat attribute model, string table deduplication, and typed attribute values.
Adds a ProtocolVersion enum to cleanly represent v0.4, v0.5, and v1.0 protocols including their fallback endpoint chains.
Updates DDAgentFeaturesDiscovery to probe endpoints based on the configured protocol version.

Motivation

Protocol v1 is a more efficient wire format: it deduplicates repeated strings via a string table, uses typed attribute values (string/bool/float/int/bytes/array). This reduces payload size and provides a cleaner foundation for future span model evolution. The implementation falls back gracefully to v0.4 when the agent does not advertise v1 support.

Additional Notes

Protocol v1 spec
System test passed both on GitHub and GitLab.

pr-commenter · 2026-03-11T00:24:38Z

Benchmarks

Startup

Parameters

	Baseline	Candidate
baseline_or_candidate	baseline	candidate
git_branch	master	alexeyk/protocol-v1-1
git_commit_date	1776788798	1776801963
git_commit_sha	`6880c80`	`2275e71`
release_version	1.62.0-SNAPSHOT~6880c80c48	1.61.0-SNAPSHOT~2275e716e1

See matching parameters

	Baseline	Candidate
application	insecure-bank	insecure-bank
ci_job_date	1776803704	1776803704
ci_job_id	1617306124	1617306124
ci_pipeline_id	108894992	108894992
cpu_model	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
kernel_version	Linux runner-zfyrx7zua-project-304-concurrent-0-09o28jq1 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux	Linux runner-zfyrx7zua-project-304-concurrent-0-09o28jq1 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
module	Agent	Agent
parent	None	None

Summary

Found 0 performance improvements and 0 performance regressions! Performance is the same for 60 metrics, 11 unstable metrics.

Startup time reports for insecure-bank

gantt
    title insecure-bank - global startup overhead: candidate=1.61.0-SNAPSHOT~2275e716e1, baseline=1.62.0-SNAPSHOT~6880c80c48

    dateFormat X
    axisFormat %s
section tracing
Agent [baseline] (1.058 s) : 0, 1058214
Total [baseline] (8.841 s) : 0, 8841355
Agent [candidate] (1.064 s) : 0, 1063648
Total [candidate] (8.846 s) : 0, 8846284
section iast
Agent [baseline] (1.228 s) : 0, 1227750
Total [baseline] (9.541 s) : 0, 9540853
Agent [candidate] (1.231 s) : 0, 1231489
Total [candidate] (9.616 s) : 0, 9615950

baseline results

Module	Variant	Duration	Δ tracing
Agent	tracing	1.058 s	-
Agent	iast	1.228 s	169.536 ms (16.0%)
Total	tracing	8.841 s	-
Total	iast	9.541 s	699.498 ms (7.9%)

candidate results

Module	Variant	Duration	Δ tracing
Agent	tracing	1.064 s	-
Agent	iast	1.231 s	167.841 ms (15.8%)
Total	tracing	8.846 s	-
Total	iast	9.616 s	769.666 ms (8.7%)

gantt
    title insecure-bank - break down per module: candidate=1.61.0-SNAPSHOT~2275e716e1, baseline=1.62.0-SNAPSHOT~6880c80c48

    dateFormat X
    axisFormat %s
section tracing
crashtracking [baseline] (1.262 ms) : 0, 1262
crashtracking [candidate] (1.232 ms) : 0, 1232
BytebuddyAgent [baseline] (634.756 ms) : 0, 634756
BytebuddyAgent [candidate] (638.805 ms) : 0, 638805
AgentMeter [baseline] (29.519 ms) : 0, 29519
AgentMeter [candidate] (29.615 ms) : 0, 29615
GlobalTracer [baseline] (248.27 ms) : 0, 248270
GlobalTracer [candidate] (249.201 ms) : 0, 249201
AppSec [baseline] (32.4 ms) : 0, 32400
AppSec [candidate] (32.267 ms) : 0, 32267
Debugger [baseline] (58.877 ms) : 0, 58877
Debugger [candidate] (59.347 ms) : 0, 59347
Remote Config [baseline] (596.8 µs) : 0, 597
Remote Config [candidate] (611.304 µs) : 0, 611
Telemetry [baseline] (7.969 ms) : 0, 7969
Telemetry [candidate] (9.457 ms) : 0, 9457
Flare Poller [baseline] (8.194 ms) : 0, 8194
Flare Poller [candidate] (6.694 ms) : 0, 6694
section iast
crashtracking [baseline] (1.261 ms) : 0, 1261
crashtracking [candidate] (1.234 ms) : 0, 1234
BytebuddyAgent [baseline] (807.307 ms) : 0, 807307
BytebuddyAgent [candidate] (808.75 ms) : 0, 808750
AgentMeter [baseline] (11.348 ms) : 0, 11348
AgentMeter [candidate] (11.393 ms) : 0, 11393
GlobalTracer [baseline] (238.216 ms) : 0, 238216
GlobalTracer [candidate] (238.837 ms) : 0, 238837
IAST [baseline] (30.936 ms) : 0, 30936
IAST [candidate] (29.91 ms) : 0, 29910
AppSec [baseline] (27.223 ms) : 0, 27223
AppSec [candidate] (26.949 ms) : 0, 26949
Debugger [baseline] (63.725 ms) : 0, 63725
Debugger [candidate] (66.391 ms) : 0, 66391
Remote Config [baseline] (526.844 µs) : 0, 527
Remote Config [candidate] (535.657 µs) : 0, 536
Telemetry [baseline] (7.696 ms) : 0, 7696
Telemetry [candidate] (7.981 ms) : 0, 7981
Flare Poller [baseline] (3.396 ms) : 0, 3396
Flare Poller [candidate] (3.485 ms) : 0, 3485

Startup time reports for petclinic

gantt
    title petclinic - global startup overhead: candidate=1.61.0-SNAPSHOT~2275e716e1, baseline=1.62.0-SNAPSHOT~6880c80c48

    dateFormat X
    axisFormat %s
section tracing
Agent [baseline] (1.058 s) : 0, 1058191
Total [baseline] (11.143 s) : 0, 11143328
Agent [candidate] (1.058 s) : 0, 1057872
Total [candidate] (11.173 s) : 0, 11173081
section appsec
Agent [baseline] (1.261 s) : 0, 1260563
Total [baseline] (11.006 s) : 0, 11005919
Agent [candidate] (1.271 s) : 0, 1271223
Total [candidate] (11.138 s) : 0, 11138007
section iast
Agent [baseline] (1.23 s) : 0, 1230168
Total [baseline] (11.314 s) : 0, 11313975
Agent [candidate] (1.233 s) : 0, 1232713
Total [candidate] (11.283 s) : 0, 11283373
section profiling
Agent [baseline] (1.186 s) : 0, 1186026
Total [baseline] (11.165 s) : 0, 11165185
Agent [candidate] (1.185 s) : 0, 1185157
Total [candidate] (11.063 s) : 0, 11063218

baseline results

Module	Variant	Duration	Δ tracing
Agent	tracing	1.058 s	-
Agent	appsec	1.261 s	202.373 ms (19.1%)
Agent	iast	1.23 s	171.978 ms (16.3%)
Agent	profiling	1.186 s	127.836 ms (12.1%)
Total	tracing	11.143 s	-
Total	appsec	11.006 s	-137.409 ms (-1.2%)
Total	iast	11.314 s	170.647 ms (1.5%)
Total	profiling	11.165 s	21.857 ms (0.2%)

candidate results

Module	Variant	Duration	Δ tracing
Agent	tracing	1.058 s	-
Agent	appsec	1.271 s	213.35 ms (20.2%)
Agent	iast	1.233 s	174.841 ms (16.5%)
Agent	profiling	1.185 s	127.285 ms (12.0%)
Total	tracing	11.173 s	-
Total	appsec	11.138 s	-35.074 ms (-0.3%)
Total	iast	11.283 s	110.292 ms (1.0%)
Total	profiling	11.063 s	-109.863 ms (-1.0%)

gantt
    title petclinic - break down per module: candidate=1.61.0-SNAPSHOT~2275e716e1, baseline=1.62.0-SNAPSHOT~6880c80c48

    dateFormat X
    axisFormat %s
section tracing
crashtracking [baseline] (1.241 ms) : 0, 1241
crashtracking [candidate] (1.235 ms) : 0, 1235
BytebuddyAgent [baseline] (632.869 ms) : 0, 632869
BytebuddyAgent [candidate] (631.818 ms) : 0, 631818
AgentMeter [baseline] (29.579 ms) : 0, 29579
AgentMeter [candidate] (29.262 ms) : 0, 29262
GlobalTracer [baseline] (249.842 ms) : 0, 249842
GlobalTracer [candidate] (249.385 ms) : 0, 249385
AppSec [baseline] (32.612 ms) : 0, 32612
AppSec [candidate] (32.321 ms) : 0, 32321
Debugger [baseline] (60.124 ms) : 0, 60124
Debugger [candidate] (60.634 ms) : 0, 60634
Remote Config [baseline] (613.227 µs) : 0, 613
Remote Config [candidate] (604.266 µs) : 0, 604
Telemetry [baseline] (8.142 ms) : 0, 8142
Telemetry [candidate] (8.845 ms) : 0, 8845
Flare Poller [baseline] (6.794 ms) : 0, 6794
Flare Poller [candidate] (7.632 ms) : 0, 7632
section appsec
crashtracking [baseline] (1.235 ms) : 0, 1235
crashtracking [candidate] (1.253 ms) : 0, 1253
BytebuddyAgent [baseline] (673.574 ms) : 0, 673574
BytebuddyAgent [candidate] (680.523 ms) : 0, 680523
AgentMeter [baseline] (12.181 ms) : 0, 12181
AgentMeter [candidate] (12.391 ms) : 0, 12391
GlobalTracer [baseline] (248.91 ms) : 0, 248910
GlobalTracer [candidate] (250.637 ms) : 0, 250637
AppSec [baseline] (186.403 ms) : 0, 186403
AppSec [candidate] (187.48 ms) : 0, 187480
Debugger [baseline] (65.664 ms) : 0, 65664
Debugger [candidate] (65.973 ms) : 0, 65973
Remote Config [baseline] (574.429 µs) : 0, 574
Remote Config [candidate] (574.197 µs) : 0, 574
Telemetry [baseline] (7.852 ms) : 0, 7852
Telemetry [candidate] (7.86 ms) : 0, 7860
Flare Poller [baseline] (3.465 ms) : 0, 3465
Flare Poller [candidate] (3.46 ms) : 0, 3460
IAST [baseline] (24.297 ms) : 0, 24297
IAST [candidate] (24.464 ms) : 0, 24464
section iast
crashtracking [baseline] (1.244 ms) : 0, 1244
crashtracking [candidate] (1.225 ms) : 0, 1225
BytebuddyAgent [baseline] (807.802 ms) : 0, 807802
BytebuddyAgent [candidate] (808.895 ms) : 0, 808895
AgentMeter [baseline] (11.391 ms) : 0, 11391
AgentMeter [candidate] (11.394 ms) : 0, 11394
GlobalTracer [baseline] (238.717 ms) : 0, 238717
GlobalTracer [candidate] (239.703 ms) : 0, 239703
AppSec [baseline] (29.229 ms) : 0, 29229
AppSec [candidate] (28.514 ms) : 0, 28514
Debugger [baseline] (64.068 ms) : 0, 64068
Debugger [candidate] (64.206 ms) : 0, 64206
Remote Config [baseline] (543.563 µs) : 0, 544
Remote Config [candidate] (539.608 µs) : 0, 540
Telemetry [baseline] (7.813 ms) : 0, 7813
Telemetry [candidate] (7.886 ms) : 0, 7886
Flare Poller [baseline] (3.431 ms) : 0, 3431
Flare Poller [candidate] (3.478 ms) : 0, 3478
IAST [baseline] (29.058 ms) : 0, 29058
IAST [candidate] (30.853 ms) : 0, 30853
section profiling
ProfilingAgent [baseline] (94.28 ms) : 0, 94280
ProfilingAgent [candidate] (93.881 ms) : 0, 93881
crashtracking [baseline] (1.185 ms) : 0, 1185
crashtracking [candidate] (1.187 ms) : 0, 1187
BytebuddyAgent [baseline] (691.4 ms) : 0, 691400
BytebuddyAgent [candidate] (691.399 ms) : 0, 691399
AgentMeter [baseline] (9.234 ms) : 0, 9234
AgentMeter [candidate] (9.271 ms) : 0, 9271
GlobalTracer [baseline] (207.386 ms) : 0, 207386
GlobalTracer [candidate] (207.232 ms) : 0, 207232
AppSec [baseline] (32.919 ms) : 0, 32919
AppSec [candidate] (32.761 ms) : 0, 32761
Debugger [baseline] (66.267 ms) : 0, 66267
Debugger [candidate] (65.843 ms) : 0, 65843
Remote Config [baseline] (584.558 µs) : 0, 585
Remote Config [candidate] (573.624 µs) : 0, 574
Telemetry [baseline] (7.783 ms) : 0, 7783
Telemetry [candidate] (7.822 ms) : 0, 7822
Flare Poller [baseline] (3.536 ms) : 0, 3536
Flare Poller [candidate] (3.592 ms) : 0, 3592
Profiling [baseline] (94.843 ms) : 0, 94843
Profiling [candidate] (94.439 ms) : 0, 94439

Load

Parameters

	Baseline	Candidate
baseline_or_candidate	baseline	candidate
git_branch	master	alexeyk/protocol-v1-1
git_commit_date	1776788798	1776801963
git_commit_sha	`6880c80`	`2275e71`
release_version	1.62.0-SNAPSHOT~6880c80c48	1.61.0-SNAPSHOT~2275e716e1

See matching parameters

	Baseline	Candidate
application	insecure-bank	insecure-bank
ci_job_date	1776804181	1776804181
ci_job_id	1617306125	1617306125
ci_pipeline_id	108894992	108894992
cpu_model	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
kernel_version	Linux runner-zfyrx7zua-project-304-concurrent-0-swq4dk7c 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux	Linux runner-zfyrx7zua-project-304-concurrent-0-swq4dk7c 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Summary

Found 1 performance improvements and 3 performance regressions! Performance is the same for 16 metrics, 16 unstable metrics.

scenario	Δ mean agg_http_req_duration_p50	Δ mean agg_http_req_duration_p95	Δ mean throughput	candidate mean agg_http_req_duration_p50	candidate mean agg_http_req_duration_p95	candidate mean throughput	baseline mean agg_http_req_duration_p50	baseline mean agg_http_req_duration_p95	baseline mean throughput
scenario:load:insecure-bank:iast_GLOBAL:high_load	worse [+120.369µs; +258.027µs] or [+4.334%; +9.290%]	unsure [+144.289µs; +583.084µs] or [+1.832%; +7.404%]	unstable [-213.394op/s; +75.957op/s] or [-16.470%; +5.863%]	2.967ms	8.239ms	1226.906op/s	2.777ms	7.875ms	1295.625op/s
scenario:load:petclinic:tracing:high_load	worse [+0.687ms; +1.488ms] or [+3.938%; +8.534%]	worse [+0.624ms; +2.362ms] or [+2.190%; +8.286%]	unstable [-39.827op/s; +13.639op/s] or [-15.185%; +5.200%]	18.523ms	29.992ms	249.188op/s	17.436ms	28.499ms	262.281op/s
scenario:load:petclinic:no_agent:high_load	better [-1.941ms; -0.382ms] or [-10.408%; -2.047%]	unstable [-3.466ms; -0.224ms] or [-11.247%; -0.727%]	unstable [-14.502op/s; +43.065op/s] or [-5.932%; +17.616%]	17.487ms	28.975ms	258.750op/s	18.648ms	30.820ms	244.469op/s

Request duration reports for petclinic

gantt
    title petclinic - request duration [CI 0.99] : candidate=1.61.0-SNAPSHOT~2275e716e1, baseline=1.62.0-SNAPSHOT~6880c80c48
    dateFormat X
    axisFormat %s
section baseline
no_agent (19.093 ms) : 18898, 19289
.   : milestone, 19093,
appsec (18.794 ms) : 18603, 18984
.   : milestone, 18794,
code_origins (17.802 ms) : 17625, 17980
.   : milestone, 17802,
iast (17.853 ms) : 17676, 18030
.   : milestone, 17853,
profiling (18.346 ms) : 18162, 18530
.   : milestone, 18346,
tracing (17.789 ms) : 17615, 17963
.   : milestone, 17789,
section candidate
no_agent (18.03 ms) : 17850, 18211
.   : milestone, 18030,
appsec (18.774 ms) : 18587, 18962
.   : milestone, 18774,
code_origins (17.968 ms) : 17789, 18147
.   : milestone, 17968,
iast (17.88 ms) : 17701, 18058
.   : milestone, 17880,
profiling (18.283 ms) : 18104, 18461
.   : milestone, 18283,
tracing (18.729 ms) : 18541, 18916
.   : milestone, 18729,

baseline results

Variant	Request duration [CI 0.99]	Δ no_agent
no_agent	19.093 ms [18.898 ms, 19.289 ms]	-
appsec	18.794 ms [18.603 ms, 18.984 ms]	-299.676 µs (-1.6%)
code_origins	17.802 ms [17.625 ms, 17.98 ms]	-1.291 ms (-6.8%)
iast	17.853 ms [17.676 ms, 18.03 ms]	-1.24 ms (-6.5%)
profiling	18.346 ms [18.162 ms, 18.53 ms]	-747.484 µs (-3.9%)
tracing	17.789 ms [17.615 ms, 17.963 ms]	-1.305 ms (-6.8%)

candidate results

Variant	Request duration [CI 0.99]	Δ no_agent
no_agent	18.03 ms [17.85 ms, 18.211 ms]	-
appsec	18.774 ms [18.587 ms, 18.962 ms]	744.027 µs (4.1%)
code_origins	17.968 ms [17.789 ms, 18.147 ms]	-62.002 µs (-0.3%)
iast	17.88 ms [17.701 ms, 18.058 ms]	-150.75 µs (-0.8%)
profiling	18.283 ms [18.104 ms, 18.461 ms]	252.481 µs (1.4%)
tracing	18.729 ms [18.541 ms, 18.916 ms]	698.425 µs (3.9%)

Request duration reports for insecure-bank

gantt
    title insecure-bank - request duration [CI 0.99] : candidate=1.61.0-SNAPSHOT~2275e716e1, baseline=1.62.0-SNAPSHOT~6880c80c48
    dateFormat X
    axisFormat %s
section baseline
no_agent (1.256 ms) : 1243, 1269
.   : milestone, 1256,
iast (3.272 ms) : 3225, 3320
.   : milestone, 3272,
iast_FULL (5.79 ms) : 5731, 5848
.   : milestone, 5790,
iast_GLOBAL (3.538 ms) : 3479, 3596
.   : milestone, 3538,
profiling (2.135 ms) : 2112, 2158
.   : milestone, 2135,
tracing (1.932 ms) : 1915, 1949
.   : milestone, 1932,
section candidate
no_agent (1.236 ms) : 1224, 1247
.   : milestone, 1236,
iast (3.211 ms) : 3169, 3253
.   : milestone, 3211,
iast_FULL (5.958 ms) : 5898, 6019
.   : milestone, 5958,
iast_GLOBAL (3.74 ms) : 3678, 3801
.   : milestone, 3740,
profiling (2.095 ms) : 2076, 2113
.   : milestone, 2095,
tracing (1.899 ms) : 1883, 1914
.   : milestone, 1899,

baseline results

Variant	Request duration [CI 0.99]	Δ no_agent
no_agent	1.256 ms [1.243 ms, 1.269 ms]	-
iast	3.272 ms [3.225 ms, 3.32 ms]	2.016 ms (160.5%)
iast_FULL	5.79 ms [5.731 ms, 5.848 ms]	4.534 ms (361.0%)
iast_GLOBAL	3.538 ms [3.479 ms, 3.596 ms]	2.282 ms (181.7%)
profiling	2.135 ms [2.112 ms, 2.158 ms]	879.07 µs (70.0%)
tracing	1.932 ms [1.915 ms, 1.949 ms]	676.193 µs (53.8%)

candidate results

Variant	Request duration [CI 0.99]	Δ no_agent
no_agent	1.236 ms [1.224 ms, 1.247 ms]	-
iast	3.211 ms [3.169 ms, 3.253 ms]	1.976 ms (159.9%)
iast_FULL	5.958 ms [5.898 ms, 6.019 ms]	4.723 ms (382.2%)
iast_GLOBAL	3.74 ms [3.678 ms, 3.801 ms]	2.504 ms (202.7%)
profiling	2.095 ms [2.076 ms, 2.113 ms]	859.421 µs (69.6%)
tracing	1.899 ms [1.883 ms, 1.914 ms]	663.119 µs (53.7%)

Dacapo

Parameters

	Baseline	Candidate
baseline_or_candidate	baseline	candidate
git_branch	master	alexeyk/protocol-v1-1
git_commit_date	1776788798	1776801963
git_commit_sha	`6880c80`	`2275e71`
release_version	1.62.0-SNAPSHOT~6880c80c48	1.61.0-SNAPSHOT~2275e716e1

See matching parameters

	Baseline	Candidate
application	biojava	biojava
ci_job_date	1776803990	1776803990
ci_job_id	1617306126	1617306126
ci_pipeline_id	108894992	108894992
cpu_model	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz	Intel(R) Xeon(R) Platinum 8259CL CPU @ 2.50GHz
kernel_version	Linux runner-zfyrx7zua-project-304-concurrent-0-hbks479w 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux	Linux runner-zfyrx7zua-project-304-concurrent-0-hbks479w 6.8.0-1031-aws #33~22.04.1-Ubuntu SMP Thu Jun 26 14:22:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Summary

Found 0 performance improvements and 0 performance regressions! Performance is the same for 11 metrics, 1 unstable metrics.

Execution time for biojava

gantt
    title biojava - execution time [CI 0.99] : candidate=1.61.0-SNAPSHOT~2275e716e1, baseline=1.62.0-SNAPSHOT~6880c80c48
    dateFormat X
    axisFormat %s
section baseline
no_agent (15.704 s) : 15704000, 15704000
.   : milestone, 15704000,
appsec (14.656 s) : 14656000, 14656000
.   : milestone, 14656000,
iast (18.731 s) : 18731000, 18731000
.   : milestone, 18731000,
iast_GLOBAL (18.092 s) : 18092000, 18092000
.   : milestone, 18092000,
profiling (14.914 s) : 14914000, 14914000
.   : milestone, 14914000,
tracing (14.799 s) : 14799000, 14799000
.   : milestone, 14799000,
section candidate
no_agent (15.528 s) : 15528000, 15528000
.   : milestone, 15528000,
appsec (14.972 s) : 14972000, 14972000
.   : milestone, 14972000,
iast (18.584 s) : 18584000, 18584000
.   : milestone, 18584000,
iast_GLOBAL (17.99 s) : 17990000, 17990000
.   : milestone, 17990000,
profiling (15.313 s) : 15313000, 15313000
.   : milestone, 15313000,
tracing (14.939 s) : 14939000, 14939000
.   : milestone, 14939000,

baseline results

Variant	Execution Time [CI 0.99]	Δ no_agent
no_agent	15.704 s [15.704 s, 15.704 s]	-
appsec	14.656 s [14.656 s, 14.656 s]	-1.048 s (-6.7%)
iast	18.731 s [18.731 s, 18.731 s]	3.027 s (19.3%)
iast_GLOBAL	18.092 s [18.092 s, 18.092 s]	2.388 s (15.2%)
profiling	14.914 s [14.914 s, 14.914 s]	-790.0 ms (-5.0%)
tracing	14.799 s [14.799 s, 14.799 s]	-905.0 ms (-5.8%)

candidate results

Variant	Execution Time [CI 0.99]	Δ no_agent
no_agent	15.528 s [15.528 s, 15.528 s]	-
appsec	14.972 s [14.972 s, 14.972 s]	-556.0 ms (-3.6%)
iast	18.584 s [18.584 s, 18.584 s]	3.056 s (19.7%)
iast_GLOBAL	17.99 s [17.99 s, 17.99 s]	2.462 s (15.9%)
profiling	15.313 s [15.313 s, 15.313 s]	-215.0 ms (-1.4%)
tracing	14.939 s [14.939 s, 14.939 s]	-589.0 ms (-3.8%)

Execution time for tomcat

gantt
    title tomcat - execution time [CI 0.99] : candidate=1.61.0-SNAPSHOT~2275e716e1, baseline=1.62.0-SNAPSHOT~6880c80c48
    dateFormat X
    axisFormat %s
section baseline
no_agent (1.49 ms) : 1478, 1502
.   : milestone, 1490,
appsec (3.811 ms) : 3589, 4033
.   : milestone, 3811,
iast (2.277 ms) : 2207, 2346
.   : milestone, 2277,
iast_GLOBAL (2.323 ms) : 2252, 2393
.   : milestone, 2323,
profiling (2.09 ms) : 2035, 2144
.   : milestone, 2090,
tracing (2.074 ms) : 2021, 2128
.   : milestone, 2074,
section candidate
no_agent (1.486 ms) : 1474, 1498
.   : milestone, 1486,
appsec (3.838 ms) : 3616, 4061
.   : milestone, 3838,
iast (2.269 ms) : 2200, 2339
.   : milestone, 2269,
iast_GLOBAL (2.315 ms) : 2245, 2385
.   : milestone, 2315,
profiling (2.11 ms) : 2055, 2165
.   : milestone, 2110,
tracing (2.072 ms) : 2018, 2125
.   : milestone, 2072,

baseline results

Variant	Execution Time [CI 0.99]	Δ no_agent
no_agent	1.49 ms [1.478 ms, 1.502 ms]	-
appsec	3.811 ms [3.589 ms, 4.033 ms]	2.321 ms (155.8%)
iast	2.277 ms [2.207 ms, 2.346 ms]	786.739 µs (52.8%)
iast_GLOBAL	2.323 ms [2.252 ms, 2.393 ms]	832.689 µs (55.9%)
profiling	2.09 ms [2.035 ms, 2.144 ms]	599.805 µs (40.3%)
tracing	2.074 ms [2.021 ms, 2.128 ms]	584.396 µs (39.2%)

candidate results

Variant	Execution Time [CI 0.99]	Δ no_agent
no_agent	1.486 ms [1.474 ms, 1.498 ms]	-
appsec	3.838 ms [3.616 ms, 4.061 ms]	2.352 ms (158.3%)
iast	2.269 ms [2.2 ms, 2.339 ms]	783.522 µs (52.7%)
iast_GLOBAL	2.315 ms [2.245 ms, 2.385 ms]	829.221 µs (55.8%)
profiling	2.11 ms [2.055 ms, 2.165 ms]	624.213 µs (42.0%)
tracing	2.072 ms [2.018 ms, 2.125 ms]	585.793 µs (39.4%)

dougqh · 2026-04-13T17:49:17Z

Besides just reviewing the code, I wanted to see how this change impacts our overhead.
Overall, the results are quite good...

throughput is mostly unchanged -- maybe slightly better in intermediate heap sizes
allocation is up, but only slightly -- this looks be from UTF-8 byte[] which can be solved with a bit of caching

I suspect throughput will improve once this branch is synchronized with master.
And we can easily add the caching later, since this protocol uses a de-duplicated string table, the increase is only 1%.

The cache will just help a little more by de-duplicating across payloads.

AlexeyKuznetsov-DD · 2026-04-13T17:53:14Z

Besides just reviewing the code, I wanted to see how this change impacts our overhead. Overall, the results are quite good...

throughput is mostly unchanged -- maybe slightly better in intermediate heap sizes

allocation is up, but only slightly -- this looks be from UTF-8 byte[] which can be solved with a bit of caching

I suspect throughput will improve once this branch is synchronized with master. And we can easily add the caching later, since this protocol uses a de-duplicated string table, the increase is only 1%.

The cache will just help a little more by de-duplicating across payloads.

Yep, totally agree on caching, we can improve in follow up PRs.
PR is already too big, so I would prefer to merge it if there no obvious issues and continue to work in smaller PRs.
Thanks for feedback!

dougqh

I have mostly left small comments that I've put throughout. Nothing critical in my view.
I do think getting one more review from someone familiar with the core would be good.

dougqh

One other performance suggestion from Claude...

StringTable lookups force String materialization and Integer boxing — TraceMapperV1.java:1695-1706, :1832-1866
Every tag name, tag value, service name, operation name, resource, component, etc. goes through:
String str = value == null ? "" : value.toString();
Integer index = stringTable.get(str);
Two issues:

value.toString() allocates a new String for every UTF8BytesString / non-String CharSequence. Given V1 is a streaming string table design intended to amortize
string cost, this re-materializes on every lookup and defeats part of the win.

HashMap<String,Integer>.get() autoboxes the returned index.

Consider a CharSequence-keyed open-addressed primitive int map (dd-trace already has UTF8ByteStringMap-like structures; verify). Even dropping to Eclipse
Collections' ObjectIntHashMap gets rid of boxing.

I'm guess StringTable is pre-existing. I agree with Claude that it would be nice to reduce the allocation especially the boxing.

But again, I'm fine with leaving this to a later PR.

dougqh

Looks good to me.

I added a couple comments based on asking Claude to do a perf review.
I do think optimizing might the ID to byte conversion would be good.
I suspect that is where some (most?) of the extra 2GiB of byte[] were coming from.

But I'm fine with doing that in a separate pull request

# Conflicts: # dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java

AlexeyKuznetsov-DD added 2 commits March 10, 2026 19:27

Protocol v1: draft implementation

fb856c0

Added chunk attributes.

37be0e8

AlexeyKuznetsov-DD self-assigned this Mar 10, 2026

AlexeyKuznetsov-DD added tag: do not merge Do not merge changes comp: core Tracer core labels Mar 10, 2026

AlexeyKuznetsov-DD added 24 commits March 10, 2026 21:56

Added process tags.

7d72919

Fixed first span metadata processing.

cd59310

Disable test temporary.

deab351

Forced to use v1 for testing.

549bef5

Merge branch 'master' into alexeyk/protocol-v1-1

5e329c5

Merge branch 'master' into alexeyk/protocol-v1-1

7d86270

Merge branch 'master' into alexeyk/protocol-v1-1

e593140

Fixed mock server to support v1 and some renaming.

c55bed4

Merge branch 'master' into alexeyk/protocol-v1-1

ca09892

Fixed v1 protocol emulation.

2e9fd4a

Merge branch 'master' into alexeyk/protocol-v1-1

c12267b

Merge branch 'master' into alexeyk/protocol-v1-1

c320eee

Added missing baggage. Fixed smoke tests.

c781a95

Merge branch 'master' into alexeyk/protocol-v1-1

a2a31b6

Flatten attrs. Fixed tests.

0450392

Merge branch 'master' into alexeyk/protocol-v1-1

c86443e

Top level.

882350a

Merge branch 'master' into alexeyk/protocol-v1-1

68e07c2

Added /info point for mock server.

a1afc49

Merge branch 'master' into alexeyk/protocol-v1-1

c41c697

Refactored code duplication.

6f232d3

Refactored protocol version to be enum instead of string.

808761a

Fixed failed tests.

1a4021d

Fixed failed tests.

690427a

AlexeyKuznetsov-DD added the type: enhancement Enhancements and improvements label Mar 31, 2026

Merge branch 'master' into alexeyk/protocol-v1-1

1a317cc

dougqh reviewed Apr 13, 2026

View reviewed changes

AlexeyKuznetsov-DD added 9 commits April 14, 2026 10:02

Merge branch 'master' into alexeyk/protocol-v1-1

d775b7f

Merge branch 'master' into alexeyk/protocol-v1-1

a797427

Fixed review notes.

f7c4197

Merge branch 'master' into alexeyk/protocol-v1-1

2e57872

Refactored code to avoid boxing objects.

98ea331

Refactored c-style loop to list iterator.

9a502fa

Merge branch 'master' into alexeyk/protocol-v1-1

88eaa19

Minor code cleanup after code review.

4158f9c

Added comment about supporting old protocols.

ca70c7d

AlexeyKuznetsov-DD requested a review from dougqh April 16, 2026 14:23

Merge branch 'master' into alexeyk/protocol-v1-1

2cb195d

dougqh reviewed Apr 16, 2026

View reviewed changes

Comment thread dd-trace-api/src/main/java/datadog/trace/api/DDTraceId.java Outdated

dougqh reviewed Apr 16, 2026

View reviewed changes

dougqh approved these changes Apr 16, 2026

View reviewed changes

AlexeyKuznetsov-DD added 5 commits April 17, 2026 14:29

Merge branch 'master' into alexeyk/protocol-v1-1

6fa2b54

Merge branch 'master' into alexeyk/protocol-v1-1

c9a31a6

Optimization of traceId serialization: do not allocate temporary buffer.

bae76f8

Java docs.

f53cfc7

Merge branch 'master' into alexeyk/protocol-v1-1

a57ea33

AlexeyKuznetsov-DD requested a review from mcculls April 20, 2026 18:50

AlexeyKuznetsov-DD added 5 commits April 21, 2026 13:24

Merge branch 'master' into alexeyk/protocol-v1-1

5266254

# Conflicts: # dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java

Merged with master.

76d8898

Refactored processTagsAndBaggage for v1 protocol.

935678f

Fixed recursion.

8e198ba

Fixed groovy compilation.

2275e71

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Protocol v1#10801

Protocol v1#10801
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