AgentSkillsCN

low-latency-systems

在后端与实时系统中设计、诊断并优化低延迟请求路径。在分析p50/p95/p99延迟回归、减少排队与锁竞争、调优网络/序列化开销、验证尾部延迟的改进，或以严格的百分位阈值准备延迟签核证据时使用此技能。

SKILL.md
--- frontmatter
name: low-latency-systems
description: Design, diagnose, and optimize low-latency request paths in backend and realtime systems. Use when profiling p50/p95/p99 latency regressions, reducing queueing and lock contention, tuning network/serialization overhead, validating tail-latency improvements, or preparing latency sign-off evidence with strict percentile gates.

Low Latency Systems

Use this skill to turn latency incidents and regressions into measurable, reproducible fixes.

Workflow

  1. •Lock measurement context first.
  • •Capture workload, concurrency, payload sizes, warmup policy, and hardware/runtime settings.
  • •Keep baseline and current runs environment-compatible.
  1. •Decompose latency path.
  • •Split end-to-end latency into ingress, queue, compute, storage/network, and egress components.
  • •Prioritize tail-latency contributors over average-only improvements.
  1. •Apply targeted latency fixes.
  • •Reduce blocking, contention, and unbounded queues.
  • •Reduce allocations/serialization overhead in hot paths.
  • •Use batching, caching, and async boundaries only when measured beneficial.
  1. •Validate percentile regressions.
  • •Compare baseline vs current percentiles (p50, p95, p99, optional p999).
  • •Gate release on configured regression thresholds.
  1. •Produce sign-off output.
  • •Provide measured deltas, affected components/files, and residual risks.
  • •Include exact rerun commands for verification.

Commands

bash
python3 scripts/compare_latency_runs.py \
  --baseline <baseline.json> \
  --current <current.json> \
  --threshold-pct 5

Treat non-zero exits as blocker regressions.

Output Contract

Return:

  1. •Latency Baseline: environment/workload assumptions.
  2. •Findings: percentile deltas and hotspot classes.
  3. •Optimization Plan: exact changes with expected impact.
  4. •Verification: rerun commands and regression gates.
  5. •Residual Risks: variance or unresolved tail spikes.

References

  • •references/workflow.md: detailed low-latency process.
  • •references/latency-playbook.md: bottleneck-to-fix mapping.
  • •references/signoff-template.md: concise sign-off format.

Execution Rules

  • •Prioritize tail latency (p95/p99) when evaluating user impact.
  • •Keep measurement setup stable across comparisons.
  • •Require before/after evidence for each claimed improvement.
  • •Escalate threshold breaches as blockers.