rippled/OpenTelemetryPlan/Phase7_taskList.md

Phase 7: Native OTel Metrics Migration — Task List

Goal: Replace StatsDCollector with a native OpenTelemetry Metrics SDK implementation behind the existing beast::insight::Collector interface, eliminating the StatsD UDP dependency.

Scope: New OTelCollectorImpl class, CollectorManager config change, OTel Collector pipeline update, Grafana dashboard metric name migration, integration tests.

Branch: pratik/otel-phase7-native-metrics (from pratik/otel-phase6-statsd)

Related Plan Documents

Document	Relevance
06-implementation-phases.md	Phase 7 plan: motivation, architecture, exit criteria (§6.8)
02-design-decisions.md	Collector interface design, beast::insight coexistence strategy
05-configuration-reference.md	[insight] and [telemetry] config sections
09-data-collection-reference.md	Complete metric inventory that must be preserved

---

Task 7.1: Add OTel Metrics SDK to Build Dependencies

Objective: Enable the OTel C++ Metrics SDK components in the build system.

What to do:

• Edit conanfile.py:

  • Add OTel metrics SDK components to the dependency list when telemetry=True
  • Components needed: opentelemetry-cpp::metrics, opentelemetry-cpp::otlp_http_metric_exporter

• Edit CMakeLists.txt (telemetry section):

  • Link opentelemetry::metrics and opentelemetry::otlp_http_metric_exporter targets

Key modified files:

• conanfile.py
• CMakeLists.txt (or the relevant telemetry cmake target)

Reference: 05-configuration-reference.md §5.3 — CMake integration

---

Task 7.2: Implement OTelCollector Class

Objective: Create the core OTelCollector implementation that maps beast::insight instruments to OTel Metrics SDK instruments.

What to do:

• Create include/xrpl/beast/insight/OTelCollector.h:

  • Public factory: static std::shared_ptr<OTelCollector> New(std::string const& endpoint, std::string const& prefix, beast::Journal journal)
  • Derives from StatsDCollector (or directly from Collector — TBD based on shared code)

• Create src/libxrpl/beast/insight/OTelCollector.cpp (~400-500 lines):

  • OTelCounterImpl: Wraps opentelemetry::metrics::Counter<int64_t>. increment(amount) calls counter->Add(amount).
  • OTelGaugeImpl: Uses opentelemetry::metrics::ObservableGauge<uint64_t> with an async callback. set(value) stores value atomically; callback reads it during collection.
  • OTelMeterImpl: Wraps opentelemetry::metrics::Counter<uint64_t>. increment(amount) calls counter->Add(amount). Semantically identical to Counter but unsigned.
  • OTelEventImpl: Wraps opentelemetry::metrics::Histogram<double>. notify(duration) calls histogram->Record(duration.count()). Uses explicit bucket boundaries matching SpanMetrics: [1, 5, 10, 25, 50, 100, 250, 500, 1000, 5000] ms.
  • OTelHookImpl: Stores handler function. Called during periodic metric collection (same 1s pattern via PeriodicMetricReader).
  • OTelCollectorImp: Main class.
    • Creates MeterProvider with PeriodicMetricReader (1s export interval)
    • Creates OtlpHttpMetricExporter pointing to [telemetry] endpoint
    • Sets resource attributes (service.name, service.instance.id) matching trace exporter
    • Implements all make_*() factory methods
    • Prefixes metric names with [insight] prefix= value

• Guard all OTel SDK includes with #ifdef XRPL_ENABLE_TELEMETRY to compile to NullCollector equivalents when telemetry disabled.

Key new files:

• include/xrpl/beast/insight/OTelCollector.h
• src/libxrpl/beast/insight/OTelCollector.cpp

Key patterns to follow:

• Match StatsDCollector.cpp structure: private impl classes, intrusive list for metrics, strand-based thread safety
• Match existing telemetry code style from src/libxrpl/telemetry/Telemetry.cpp
• Use RAII for MeterProvider lifecycle (shutdown on destructor)

Reference: 04-code-samples.md — code style and patterns

---

Task 7.3: Update CollectorManager

Objective: Add server=otel config option to route metric creation to the new OTel backend.

What to do:

• Edit src/xrpld/app/main/CollectorManager.cpp:

  • In the constructor, add a third branch after server == "statsd":

    else if (server == "otel")
    {
        // Read endpoint from [telemetry] section
        auto const endpoint = get(telemetryParams, "endpoint",
            "http://localhost:4318/v1/metrics");
        std::string const& prefix(get(params, "prefix"));
        m_collector = beast::insight::OTelCollector::New(
            endpoint, prefix, journal);
    }
    

  • This requires access to the [telemetry] config section — may need to pass it as a parameter or read from Application config.

• Edit src/xrpld/app/main/CollectorManager.h:

  • Add #include <xrpl/beast/insight/OTelCollector.h>

Key modified files:

• src/xrpld/app/main/CollectorManager.cpp
• src/xrpld/app/main/CollectorManager.h

---

Task 7.4: Update OTel Collector Configuration

Objective: Add a metrics pipeline to the OTLP receiver and remove the StatsD receiver dependency.

What to do:

• Edit docker/telemetry/otel-collector-config.yaml:

  • Remove statsd receiver (no longer needed when server=otel)
  • Add metrics pipeline under service.pipelines:

    metrics:
      receivers: [otlp, spanmetrics]
      processors: [batch]
      exporters: [prometheus]
    

  • The OTLP receiver already listens on :4318 — it just needs to be added to the metrics pipeline receivers.
  • Keep spanmetrics connector in the metrics pipeline so span-derived RED metrics continue working.

• Edit docker/telemetry/docker-compose.yml:

  • Remove UDP :8125 port mapping from otel-collector service
  • Update xrpld service config: change [insight] server=statsd to server=otel

Key modified files:

• docker/telemetry/otel-collector-config.yaml
• docker/telemetry/docker-compose.yml

Note: Keep a commented-out statsd receiver block for operators who need backward compatibility.

---

Task 7.5: Preserve Metric Names in Prometheus

Objective: Ensure existing Grafana dashboards continue working with identical metric names.

What to do:

• In OTelCollector.cpp, construct OTel instrument names to match existing Prometheus metric names:

  • beast::insight make_gauge("LedgerMaster", "Validated_Ledger_Age") → OTel instrument name: xrpld_LedgerMaster_Validated_Ledger_Age
  • The prefix + group + name concatenation must produce the same string as StatsDCollector's format
  • Use underscores as separators (matching StatsD convention)

• Verify in integration test that key Prometheus queries still return data:

  • xrpld_LedgerMaster_Validated_Ledger_Age
  • xrpld_Peer_Finder_Active_Inbound_Peers
  • xrpld_rpc_requests

Key consideration: OTel Prometheus exporter may normalize metric names differently than StatsD receiver. Test this early (Task 7.2) and adjust naming strategy if needed. The OTel SDK's Prometheus exporter adds _total suffix to counters and converts dots to underscores — match existing conventions.

---

Task 7.6: Update Grafana Dashboards

Objective: Update the 3 StatsD dashboards if any metric names change due to OTLP export format differences.

What to do:

• If Task 7.5 confirms metric names are preserved exactly, no dashboard changes needed.
• If OTLP export produces different names (e.g., _total suffix on counters), update:
  • docker/telemetry/grafana/dashboards/statsd-node-health.json
  • docker/telemetry/grafana/dashboards/statsd-network-traffic.json
  • docker/telemetry/grafana/dashboards/statsd-rpc-pathfinding.json
• Rename dashboard titles from "StatsD" to "System Metrics" or similar (since they're no longer StatsD-sourced).

Key modified files:

• docker/telemetry/grafana/dashboards/statsd-*.json (3 files, conditionally)

---

Task 7.7: Update Integration Tests

Objective: Verify the full OTLP metrics pipeline end-to-end.

What to do:

• Edit docker/telemetry/integration-test.sh:
  • Update test config to use [insight] server=otel
  • Verify metrics arrive in Prometheus via OTLP (not StatsD)
  • Add check that StatsD receiver is no longer required
  • Preserve all existing metric presence checks

Key modified files:

• docker/telemetry/integration-test.sh

---

Task 7.8: Update Documentation

Objective: Update all plan docs, runbook, and reference docs to reflect the migration.

What to do:

• Edit docs/telemetry-runbook.md:

  • Update [insight] config examples to show server=otel
  • Update troubleshooting section (no more StatsD UDP debugging)

• Edit OpenTelemetryPlan/09-data-collection-reference.md:

  • Update Data Flow Overview diagram (remove StatsD receiver)
  • Update Section 2 header from "StatsD Metrics" to "System Metrics (OTel native)"
  • Update config examples

• Edit OpenTelemetryPlan/05-configuration-reference.md:

  • Add server=otel option to [insight] section docs

• Edit docker/telemetry/TESTING.md:

  • Update setup instructions to use server=otel

Key modified files:

• docs/telemetry-runbook.md
• OpenTelemetryPlan/09-data-collection-reference.md
• OpenTelemetryPlan/05-configuration-reference.md
• docker/telemetry/TESTING.md

---

Task 7.9: ValidationTracker — Validation Agreement Computation

Source: External Dashboard Parity — the most valuable metric from the community xrpl-validator-dashboard.

Upstream: Phase 4 Task 4.8 (validation span attributes provide ledger hash context). Downstream: Phase 9 (Validator Health dashboard), Phase 10 (validation checks), Phase 11 (agreement alert rules).

Objective: Implement a stateful class that tracks whether our validator's validations agree with network consensus, maintaining rolling 1h and 24h windows with an 8-second grace period and 5-minute late repair window.

Architecture:

consensus.validation.send ────> ValidationTracker ────> MetricsRegistry
(records our validation         (reconciles after       (exports agreement
 for ledger X)                   8s grace period)        gauges every 10s)

ledger.validate ──────────────> ValidationTracker
(records which ledger           (marks ledger X as
 network validated)              agreed or missed)

What to do:

• Create src/xrpld/telemetry/ValidationTracker.h:

  • recordOurValidation(ledgerHash, ledgerSeq) — called when we send a validation
  • recordNetworkValidation(ledgerHash, seq) — called when a ledger is fully validated
  • reconcile() — called periodically; reconciles pending ledger events after 8s grace period
  • Getters: agreementPct1h(), agreementPct24h(), agreements1h(), missed1h(), agreements24h(), missed24h(), totalAgreements(), totalMissed(), totalValidationsSent(), totalValidationsChecked()
  • Thread-safety: atomics for counters, mutex for window deques

• Create src/xrpld/telemetry/detail/ValidationTracker.cpp:

  • Reconciliation logic: after 8s grace period, check if weValidated && networkValidated && sameHash → agreement; else missed
  • Late repair: if a late validation arrives within 5 minutes, correct a false-positive miss
  • Sliding window: std::deque<WindowEvent> evicts entries older than 1h/24h on each reconciliation pass
  • Ring buffer of 1000 LedgerEvent structs for pending reconciliation

• Add recording hooks (modifying Phase 4 code from Phase 7 branch):

  • RCLConsensus.cpp validate(): call tracker.recordOurValidation()
  • LedgerMaster.cpp fully-validated path: call tracker.recordNetworkValidation()

Key data structures:

struct LedgerEvent {
    uint256 ledgerHash;
    LedgerIndex seq;
    TimePoint closeTime;
    bool weValidated = false;
    bool networkValidated = false;
    bool reconciled = false;
    bool agreed = false;
};

struct WindowEvent {
    TimePoint time;
    bool agreed;
};

Key new files:

• src/xrpld/telemetry/ValidationTracker.h
• src/xrpld/telemetry/detail/ValidationTracker.cpp

Key modified files:

• src/xrpld/telemetry/MetricsRegistry.h (add ValidationTracker member)
• src/xrpld/telemetry/MetricsRegistry.cpp (add gauge callback reading from tracker)
• src/xrpld/app/consensus/RCLConsensus.cpp (add recording hooks)
• src/xrpld/app/ledger/detail/LedgerMaster.cpp (add recording hook)

Exit Criteria:

• ValidationTracker correctly tracks agreement with 8s grace period
• 5-minute late repair corrects false-positive misses
• Thread-safe (atomics + mutex for window deques)
• Rolling windows correctly evict stale entries
• Unit tests: normal agreement, missed validation, late repair, window eviction

---

Task 7.10: Validator Health Observable Gauges

Source: External Dashboard Parity

Objective: Export amendment blocked, UNL health, and quorum data as a native OTel observable gauge.

What to do:

• In MetricsRegistry.cpp registerAsyncGauges(), add:

validatorHealthGauge_ = meter_->CreateDoubleObservableGauge(
    "xrpld_validator_health", "Validator health indicators");

Gauge label values:

Label metric=	Type	Source
amendment_blocked	int64	app_.getOPs().isAmendmentBlocked() → 0/1
unl_blocked	int64	app_.getOPs().isUNLBlocked() → 0/1
unl_expiry_days	double	app_.validators().expires() → days until expiry
validation_quorum	int64	app_.validators().quorum()

Sub-task 7.10a: Per-Validator Validation Count (Flag Ledger Window)

Objective: Track how many ledgers each UNL validator has validated over the last 256 consecutive ledgers (one flag ledger window). This is the key UNL participation metric — validators consistently below threshold may be candidates for removal from the UNL.

What to do:

• Add a new observable gauge:

validatorParticipationGauge_ = meter_->CreateInt64ObservableGauge(
    "xrpld_validator_participation",
    "Per-validator validation count over the last 256 ledgers");

• The callback queries app_.getValidations() to get the trusted validation set for each of the last 256 ledger hashes (from LedgerMaster::getValidatedLedger() walking backwards). For each validator public key in the UNL, count how many of those 256 ledgers have a matching validation.

• Label dimensions:

  • validator — base58-encoded validator master public key
  • exported_instance — this node's identity (standard)

• Emission: every flag ledger (256 ledgers, ~15 minutes) or on a 10-second async gauge callback with cached results (recompute only at flag ledger boundaries).

• Data source: RCLValidations::getTrustedForLedger(hash, seq) returns std::vector<std::shared_ptr<STValidation>> with getSignerPublic() for each. The UNL list is from app_.getValidators().getTrustedMasterKeys().

• Dashboard panel: Add a table panel to the Validator Health dashboard showing xrpld_validator_participation grouped by validator label, with a threshold color (green >= 240, yellow >= 200, red < 200).

Key modified files: src/xrpld/telemetry/MetricsRegistry.h/.cpp

Exit Criteria:

• Gauge emits one time series per UNL validator
• Values range 0-256 and update at flag ledger boundaries
• Grafana table panel shows per-validator participation
• Validators below 75% participation are highlighted in red

---

Key modified files: src/xrpld/telemetry/MetricsRegistry.h/.cpp

Exit Criteria:

• All 4 base label values emitted every 10s
• unl_expiry_days is negative when expired, positive when active
• Per-validator participation gauge emits at flag ledger boundaries
• Values visible in Prometheus

---

Task 7.11: Peer Quality Observable Gauges

Source: External Dashboard Parity

Objective: Export peer health aggregates (latency P90, insane peers, version awareness) as a native OTel observable gauge.

What to do:

• In MetricsRegistry.cpp registerAsyncGauges(), add a callback that iterates app_.overlay().foreach(...) to:
  • Collect per-peer latency values, sort, compute P90
  • Count peers with tracking_ == diverged (insane)
  • Compare peer getVersion() to own version for upgrade awareness

Gauge label values:

Label metric=	Type	Source
peer_latency_p90_ms	double	P90 from sorted peer latencies
peers_insane_count	int64	Peers with diverged tracking status
peers_higher_version_pct	double	% of peers on newer xrpld version
upgrade_recommended	int64	1 if peers_higher_version_pct > 60%

Implementation note: The callback runs every 10s on the metrics reader thread. Iterating ~50-200 peers is acceptable overhead.

Key modified files: src/xrpld/telemetry/MetricsRegistry.h/.cpp

Exit Criteria:

• P90 latency computed correctly
• Insane count matches peers RPC output
• Version comparison handles format variations (e.g., "xrpld-2.4.0-rc1")

---

Task 7.12: Ledger Economy Observable Gauges

Source: External Dashboard Parity

Objective: Export fee, reserve, ledger age, and transaction rate as a native OTel observable gauge.

Gauge label values:

Label metric=	Type	Source
base_fee_xrp	double	Base fee from validated ledger fee settings (drops)
reserve_base_xrp	double	Account reserve from validated ledger (drops)
reserve_inc_xrp	double	Owner reserve increment (drops)
ledger_age_seconds	double	now - lastValidatedCloseTime
transaction_rate	double	Derived: tx count delta / time delta (smoothed)

Key modified files: src/xrpld/telemetry/MetricsRegistry.h/.cpp

Exit Criteria:

• Fee values match server_info RPC output
• ledger_age_seconds increases monotonically between ledger closes
• transaction_rate is smoothed (rolling average)

---

Task 7.13: State Tracking Observable Gauges

Source: External Dashboard Parity

Objective: Export extended state value (0-6 encoding combining OperatingMode + ConsensusMode) and time-in-current-state.

Gauge label values:

Label metric=	Type	Source
state_value	int64	0-6 encoding (see spec for mapping)
time_in_current_state_seconds	double	now - lastModeChangeTime from StateAccounting

State value encoding: 0=disconnected, 1=connected, 2=syncing, 3=tracking, 4=full, 5=validating (full + validating), 6=proposing (full + proposing).

Key modified files: src/xrpld/telemetry/MetricsRegistry.h/.cpp

Exit Criteria:

• state_value correctly combines OperatingMode and ConsensusMode
• time_in_current_state_seconds resets on mode change

---

Task 7.14: Storage Detail and Sync Info Gauges

Source: External Dashboard Parity

Objective: Export NuDB-specific storage size and initial sync duration.

Gauge label values:

Gauge Name	Label metric=	Type	Source
xrpld_storage_detail	nudb_bytes	int64	NuDB backend file size
xrpld_sync_info	initial_sync_duration_seconds	double	Time from start to first FULL

Key modified files: src/xrpld/telemetry/MetricsRegistry.h/.cpp

Exit Criteria:

• NuDB file size reported in bytes (0 if NuDB not configured)
• Sync duration captured once and remains stable after reaching FULL

---

Task 7.15: New Synchronous Counters

Source: External Dashboard Parity

Objective: Add 7 new event counters incremented at their respective instrumentation sites.

Counter Name	Increment Site	Source File
xrpld_ledgers_closed_total	onAccept() in consensus	RCLConsensus.cpp
xrpld_validations_sent_total	validate() in consensus	RCLConsensus.cpp
xrpld_validations_checked_total	Network validation received	LedgerMaster.cpp
xrpld_validation_agreements_total	ValidationTracker reconciliation	ValidationTracker.cpp
xrpld_validation_missed_total	ValidationTracker reconciliation	ValidationTracker.cpp
xrpld_state_changes_total	setMode() in NetworkOPs	NetworkOPs.cpp
xrpld_jq_trans_overflow_total	Job queue overflow path	JobQueue.cpp

Key modified files: src/xrpld/telemetry/MetricsRegistry.h/.cpp (declarations), plus recording sites in RCLConsensus.cpp, LedgerMaster.cpp, NetworkOPs.cpp, JobQueue.cpp

Exit Criteria:

• All 7 counters monotonically increase during normal operation
• Counter values match expected rates (e.g., ledgers_closed ≈ 1 per 3-5s)

---

Task 7.16: Validation Agreement Observable Gauge

Source: External Dashboard Parity

Objective: Export rolling window agreement stats from ValidationTracker (Task 7.9).

Gauge label values:

Gauge Name	Label metric=	Type	Source
xrpld_validation_agreement	agreement_pct_1h	double	tracker.agreementPct1h()
	agreements_1h	int64	tracker.agreements1h()
	missed_1h	int64	tracker.missed1h()
	agreement_pct_24h	double	tracker.agreementPct24h()
	agreements_24h	int64	tracker.agreements24h()
	missed_24h	int64	tracker.missed24h()

Key modified files: src/xrpld/telemetry/MetricsRegistry.cpp

Exit Criteria:

• Agreement percentages in range [0.0, 100.0]
• Window stats stabilize after 1h/24h of operation

---

Summary Table

Task	Description	New Files	Modified Files	Depends On
7.1	Add OTel Metrics SDK to build deps	0	2	—
7.2	Implement OTelCollector class	2	0	7.1
7.3	Update CollectorManager config routing	0	2	7.2
7.4	Update OTel Collector YAML and Docker	0	2	7.3
7.5	Preserve metric names in Prometheus	0	1	7.2
7.6	Update Grafana dashboards (if needed)	0	3	7.5
7.7	Update integration tests	0	1	7.4
7.8	Update documentation	0	4	7.6
7.9	ValidationTracker (agreement tracking)	2	4	7.2, P4.8
7.10	Validator health observable gauges	0	2	7.2
7.11	Peer quality observable gauges	0	2	7.2
7.12	Ledger economy observable gauges	0	2	7.2
7.13	State tracking observable gauges	0	2	7.2
7.14	Storage detail and sync info gauges	0	2	7.2
7.15	New synchronous counters	0	6	7.2
7.16	Validation agreement observable gauge	0	1	7.9

Parallel work: Tasks 7.4 and 7.5 can run in parallel after 7.2/7.3 complete. Task 7.6 depends on 7.5's findings. Tasks 7.7 and 7.8 can run in parallel after 7.6. Tasks 7.10-7.14 can all run in parallel after 7.2. Task 7.15 depends on 7.2. Task 7.16 depends on 7.9. Task 7.9 depends on 7.2 and Phase 4 Task 4.8.

Exit Criteria (from 06-implementation-phases.md §6.8):

• All 255+ metrics visible in Prometheus via OTLP pipeline (no StatsD receiver)
• server=otel is the default in development docker-compose
• server=statsd still works as a fallback
• Existing Grafana dashboards display data correctly
• Integration test passes with OTLP-only metrics pipeline
• No performance regression vs StatsD baseline (< 1% CPU overhead)
• Deferred Task 6.1 (|m wire format) no longer relevant — Meter mapped to OTel Counter
• ValidationTracker agreement % stabilizes after 1h under normal consensus
• All new gauges and counters visible in Prometheus with non-zero values