feat(debugger): implement intelligent snapshot pruning for oversized payloads

[watson]

What does this PR do?

Implements an intelligent snapshot pruning algorithm for Dynamic Instrumentation/Live Debugger that selectively removes the largest and deepest leaf nodes from oversized payloads while preserving the overall schema structure. This replaces the previous approach which simply deleted all captured variables when a snapshot exceeded the 1MB size limit.

Motivation

Align with how the other tracers prunes large snapshots.

Previously, when a snapshot payload exceeded 1MB, we would delete all captures entirely and show an error message to users. This was a poor user experience because users would lose all captured variable data, even though most of the snapshot was likely still valuable.

With this new pruning algorithm, we can intelligently reduce the size of oversized snapshots by removing only the least valuable data (deepest, largest nodes, and nodes that were already truncated due to depth limits), allowing users to still see most of their captured variables even when dealing with large data structures.

Additional Notes

The pruning algorithm:

• Parses snapshots into a tree structure tracking JSON object positions
• Uses a priority queue to select nodes for pruning based on:
  1. Presence of notCapturedReason: 'depth' (highest priority - already truncated data)
  2. Depth level (deeper nodes pruned first)
  3. Presence of any notCapturedReason (any truncated data)
  4. Size (larger nodes pruned first)
• Only prunes nodes at level 6 or deeper (locals and below)
• Promotes parent nodes when all children are pruned to reduce overhead
• Iteratively prunes if needed to reach target size
• Falls back to prune all everything if pruning fails or errors out

[github-actions]

Overall package size

Self size: 13.45 MB
Deduped: 113.64 MB
No deduping: 128.66 MB

Dependency sizes

| name | version | self size | total size | |------|---------|-----------|------------| | @datadog/libdatadog | 0.7.0 | 35.02 MB | 35.02 MB | | @datadog/native-appsec | 10.3.0 | 20.73 MB | 20.74 MB | | @datadog/pprof | 5.12.0 | 11.19 MB | 11.57 MB | | @datadog/native-iast-taint-tracking | 4.1.0 | 9.01 MB | 9.02 MB | | @opentelemetry/resources | 1.30.1 | 557.67 kB | 7.71 MB | | @opentelemetry/core | 1.30.1 | 908.66 kB | 7.16 MB | | protobufjs | 7.5.4 | 2.95 MB | 5.83 MB | | @datadog/wasm-js-rewriter | 5.0.1 | 2.82 MB | 3.53 MB | | @datadog/native-metrics | 3.1.1 | 1.02 MB | 1.43 MB | | @opentelemetry/api-logs | 0.208.0 | 199.48 kB | 1.42 MB | | @opentelemetry/api | 1.9.0 | 1.22 MB | 1.22 MB | | jsonpath-plus | 10.3.0 | 617.18 kB | 1.08 MB | | import-in-the-middle | 1.15.0 | 127.66 kB | 856.24 kB | | lru-cache | 10.4.3 | 804.3 kB | 804.3 kB | | @datadog/openfeature-node-server | 0.2.0 | 118.51 kB | 437.19 kB | | opentracing | 0.14.7 | 194.81 kB | 194.81 kB | | source-map | 0.7.6 | 185.63 kB | 185.63 kB | | pprof-format | 2.2.1 | 163.06 kB | 163.06 kB | | @datadog/sketches-js | 2.1.1 | 109.9 kB | 109.9 kB | | @isaacs/ttlcache | 2.1.2 | 90.79 kB | 90.79 kB | | lodash.sortby | 4.7.0 | 75.76 kB | 75.76 kB | | ignore | 7.0.5 | 63.38 kB | 63.38 kB | | istanbul-lib-coverage | 3.2.2 | 34.37 kB | 34.37 kB | | rfdc | 1.4.1 | 27.15 kB | 27.15 kB | | dc-polyfill | 0.1.10 | 26.73 kB | 26.73 kB | | tlhunter-sorted-set | 0.1.0 | 24.94 kB | 24.94 kB | | shell-quote | 1.8.3 | 23.74 kB | 23.74 kB | | limiter | 1.1.5 | 23.17 kB | 23.17 kB | | retry | 0.13.1 | 18.85 kB | 18.85 kB | | semifies | 1.0.0 | 15.84 kB | 15.84 kB | | jest-docblock | 29.7.0 | 8.99 kB | 12.76 kB | | crypto-randomuuid | 1.0.0 | 11.18 kB | 11.18 kB | | ttl-set | 1.0.0 | 4.61 kB | 9.69 kB | | mutexify | 1.4.0 | 5.71 kB | 8.74 kB | | path-to-regexp | 0.1.12 | 6.6 kB | 6.6 kB | | module-details-from-path | 1.0.4 | 3.96 kB | 3.96 kB | | escape-string-regexp | 5.0.0 | 3.66 kB | 3.66 kB |

_{🤖 This report was automatically generated by heaviest-objects-in-the-universe}

[watson]

• feat(debugger): implement intelligent snapshot pruning for oversized payloads #7006 👈 (View in Graphite)
• master

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.94%. Comparing base (7a4b1c3) to head (693c32a).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #7006   +/-   ##
=======================================
  Coverage   84.94%   84.94%           
=======================================
  Files         514      514           
  Lines       21754    21754           
=======================================
  Hits        18478    18478           
  Misses       3276     3276           

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[pr-commenter]

Benchmarks

Benchmark execution time: 2025-12-01 10:51:29

Comparing candidate commit 693c32a in PR branch watson/DEBUG-2624/implement-pruning-algo with baseline commit 7a4b1c3 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 292 metrics, 28 unstable metrics.

[datadog-datadog-prod-us1]

⚠️ Tests

⚠️ Warnings

🧪 1 Test failed

Plugin couchbase with couchbase ^3.0.7 (3.0.7) without configuration "before each" hook for "should catch errors in callback and report error in trace" from errors are handled correctly in callbacks (Datadog)

Timeout of 5000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/home/runner/work/dd-trace-js/dd-trace-js/packages/datadog-plugin-couchbase/test/index.spec.js)

Error: Timeout of 5000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/home/runner/work/dd-trace-js/dd-trace-js/packages/datadog-plugin-couchbase/test/index.spec.js)
    at listOnTimeout (node:internal/timers:559:17)
    at processTimers (node:internal/timers:502:7)

ℹ️ Info

❄️ No new flaky tests detected

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