Tycho Cloudwatch Logs

Tycho Cloudwatch Logs

Overview

Use AWS CLI to inspect Tycho simulation logs in CloudWatch. Default log group is /ecs/tycho-simulator in eu-central-1. Logs are JSON from tracing_subscriber, so queries parse @message to extract msg, level, and structured fields.

If you hit ExpiredTokenException, refresh the AWS_SESSION_TOKEN in .env and retry.

Simulate completion logs are now emitted at info level for successful requests and include extra context (tokens, latency, top pool details, and failure summaries). For detailed failure summaries, inspect the raw @message JSON. The raw completion logs emit wire-aligned quote_status, quote_result_quality, and partial_kind; the bundled query presets map those back to concise columns for triage. token-rpc-fetch is most useful for failures under the default log level; the success path only appears when RUST_LOG=debug. uniswap-v4-filter logs include filter_rule, considered_pools, accepted_pools, filtered_pools, pools_with_hook_identifier, and pools_missing_hook_identifier to explain hook-pool coverage.

Quick start

0. Who am I / which env: zsh skills/tycho-cloudwatch-logs/scripts/cw_whoami.zsh
1. List recent streams: zsh skills/tycho-cloudwatch-logs/scripts/cw_streams.zsh --limit 10
2. Tail (JSON pretty print): zsh skills/tycho-cloudwatch-logs/scripts/cw_tail.zsh --since 15m --follow
3. Filter: zsh skills/tycho-cloudwatch-logs/scripts/cw_filter.zsh --since 2h --filter-pattern "Block update:"
4. Query: zsh skills/tycho-cloudwatch-logs/scripts/cw_query.zsh --preset resync --since 24h

ERC4626 rollout checks

For ERC4626 /simulate rollout triage, use the existing presets instead of adding a new one: simulate-requests, simulate-completions, simulate-successes, and simulate-runs.

Use simulate-completions when you need to inspect degraded ready outcomes. simulate-successes is intentionally narrower and only shows quoteable ready completions (result_quality=complete|partial).

Supported ERC4626 directions on this server today:

• USDS -> sUSDS
• sUSDS -> USDS
• USDC -> sUSDC
• sUSDC -> USDC
• PYUSD -> spPYUSD
• spPYUSD -> PYUSD

Negative probe to keep handy:

• sUSDe -> USDe

Current observability limits:

• ERC4626 candidate drops are still logged at debug, so those per-candidate skip reasons remain invisible in CloudWatch under the default info log level.
• Unsupported ERC4626 /encode rejections are now visible in CloudWatch, but there is still no dedicated preset for them.
• General /encode traffic still does not include enough pair or protocol detail to isolate all ERC4626 activity reliably in CloudWatch.
• router-timeouts covers both /simulate and /encode router-boundary timeout logs, but it is not pair-aware.

Start with references/queries.md for copyable ERC4626 pair filters built on top of the existing presets.

Preset catalog

Scripts

• scripts/cw_streams.zsh: list recent log streams by last event time.
• scripts/cw_tail.zsh: live tail with optional filter and stream prefix (default format: json).
• scripts/cw_filter.zsh: time-window search with filter patterns.
• scripts/cw_query.zsh: Logs Insights queries with presets and JSON parsing.
• scripts/cw_query_ceiling.py: windowed preset runner with safety ceilings (max_rows, max_scanned_gb, max_queries).
• scripts/cw_metrics.zsh: memory/cpu metrics summaries and time series.
• scripts/analyze_snapshot.py: render a production snapshot markdown report from query + metrics JSON outputs.
• scripts/cw_time.py: time parsing helper for cw_filter, cw_query, and cw_metrics.

Snapshot report workflow

• Prompt source: ~/.codex/prompts/sim-report.md.
• Default period in the prompt is 12h when no argument is provided.
• Default sampling mode for snapshot reports uses a single query with --limit 10000 for simulate-runs and simulate-completions, regardless of time window.
• Use cw_query_ceiling.py for simulate-runs and simulate-completions only when the user explicitly requests broader sampling coverage.
• Explicit coverage directives can be expressed as sample 50%, up to 1m logs, or sample 50% up to 1m logs.
• When expanded coverage is explicitly requested, keep safety ceilings enabled: max_rows=6000000, max_scanned_gb=60, max_queries=1200, window_seconds=900.
• Required generated files for the analyzer: simulate-runs-per-minute.json, simulate-runs-per-auction.json, simulate-runs.json, simulate-requests-per-auction.json, simulate-completions.json, simulate-workload-summary.json, cw-metrics.json.

Metrics

Quick checks for memory and CPU utilization using ECS ContainerInsights.

• Memory + CPU summary + series: zsh skills/tycho-cloudwatch-logs/scripts/cw_metrics.zsh --since 12h --metrics memory,cpu
• Pivot spike check: zsh skills/tycho-cloudwatch-logs/scripts/cw_metrics.zsh --since 2h --pivot 2026-02-04T11:38:00Z --window 10m

Override defaults

• Set TYCHO_LOG_GROUP for another log group.
• Set AWS_REGION or AWS_DEFAULT_REGION for another region.
• Set TYCHO_ECS_CLUSTER or TYCHO_ECS_SERVICE to override ECS defaults for metrics.
• Pass --log-group on any script to override.

References

Use references/queries.md for the full preset index and filter/query snippets. Use docs/quote_service.md for the /simulate quote-status, result-quality, and partial-kind contract.

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