apollo_l1_gas_price: parameterize ExchangeRateOracleClient by metric set

[ShahakShama]

Goal: Prerequisite for PR #14158 (02_provider_holds_oracle). Before that
PR introduces a second ExchangeRateOracleClient for STRK→USD,
parameterize the client by metric set so the two oracles update disjoint
Prometheus series instead of contaminating each other's gauges and
counters. Closes the issue flagged by Cursor bugbot + matanl-starkware on
PR #14158.

Change summary:

• apollo_l1_gas_price::metrics defines ExchangeRateOracleMetrics
  (rate, success_count, error_count, last_success_timestamp) as a
  Copy struct of &'static refs, plus two pub const instances:
  ETH_TO_STRK_ORACLE_METRICS and STRK_TO_USD_ORACLE_METRICS.
• SNIP35_STRK_USD_RATE moves from apollo_consensus_orchestrator::metrics
  into apollo_l1_gas_price::metrics, keeping the Prometheus name
  snip35_strk_usd_rate so the existing Grafana panel keeps working
  without a query rewrite.
• Adds three new SNIP-35 metrics owned by the oracle client:
  snip35_strk_usd_success_count, snip35_strk_usd_error_count,
  snip35_strk_usd_last_success_timestamp_seconds.
• ExchangeRateOracleClient::new(config, metrics) now stores the metric
  set; spawn_query, resolve_query, and fetch_rate route through
  self.metrics.* instead of hardcoded ETH_TO_STRK_* symbols. Manual
  Debug impl on ExchangeRateOracleMetrics (the underlying
  MetricCounter/MetricGauge don't derive Debug) prints prom names.
• L1GasPriceProvider::new_with_oracle passes ETH_TO_STRK_ORACLE_METRICS
  to the existing client; PR 02 will pass STRK_TO_USD_ORACLE_METRICS to
  its new client.
• SequencerConsensusContext::compute_snip35_fee_proposal stops calling
  SNIP35_STRK_USD_RATE.set_lossy(rate); the oracle client publishes that
  gauge itself now. Consensus still reads the rate to compute fee_target.
• apollo_dashboard::panels::consensus imports SNIP35_STRK_USD_RATE (and
  the 3 new metrics) from apollo_l1_gas_price instead of
  apollo_consensus_orchestrator; adds 3 new panels (success / error /
  seconds-since-last-update) to the SNIP-35 row, matching the ETH→STRK
  panel patterns.
• dev_grafana.json updated by hand to add the 3 new panel entries; the
  Rust toolchain is unavailable in this environment so the generator
  could not be re-run. Verify locally with
  cargo run --bin sequencer_dashboard_generator before pushing.

Decision points:

• Reuse snip35_strk_usd_rate rather than defining a new
  strk_to_usd_rate: the existing time series + Grafana panel keep
  continuity, and the SNIP-35 dashboard row is the natural home for the
  STRK→USD oracle gauges.
• Move the metric definition into apollo_l1_gas_price (owner) rather
  than keeping it in apollo_consensus_orchestrator and passing a
  &'static reference down: avoids cross-crate metric ownership and
  preserves the existing one-way crate dependency
  (consensus → l1_gas_price_types).
• pub const struct of &'static refs (matches the existing
  TEST_LOCAL_SERVER_METRICS pattern in apollo_infra) rather than
  static: lets ExchangeRateOracleClient store the set by value (Copy)
  with no lifetime annotations on the struct.
• Add all 3 observability metrics (success/error/timestamp) symmetrically
  with the ETH→STRK side rather than just the rate: keeps the new
  dashboard row useful — "did the STRK→USD query just fail or just stop
  firing?" is answerable without leaning on log queries.

Co-Authored-By: Claude Opus 4.7 (1M context) noreply@anthropic.com

[cursor]

PR Summary

Low Risk
Refactors metric ownership and observability wiring without changing SNIP-35 fee math; existing snip35_strk_usd_rate series name is preserved for dashboards.

Overview
ExchangeRateOracleClient now takes an ExchangeRateOracleMetrics bundle at construction so ETH→STRK and STRK→USD clients can update separate Prometheus series (rate, success/error counters, last-success timestamp) instead of sharing hardcoded ETH_TO_STRK_* symbols.

snip35_strk_usd_rate and three new STRK→USD oracle metrics are defined and registered in apollo_l1_gas_price (same Prometheus name for the rate gauge). apollo_consensus_orchestrator drops that gauge and stops calling set_lossy on the rate in compute_snip35_fee_proposal; the oracle client publishes the rate when queries succeed. Consensus still uses the fetched rate for fee_target.

L1GasPriceProvider::new_with_oracle passes ETH_TO_STRK_ORACLE_METRICS. The SNIP-35 Grafana row imports STRK/USD metrics from apollo_l1_gas_price and adds panels for query success, errors, and time since last successful update (plus matching dev_grafana.json entries).

^{Reviewed by Cursor Bugbot for commit 2a6a5dd. Bugbot is set up for automated code reviews on this repo. Configure here.}

[reviewable-StarkWare]

This change is 

[ShahakShama]

• apollo_consensus_orchestrator: add SNIP-35 integration TODO doc #13982
• apollo_consensus_orchestrator: tmp dirty tests for SNIP-35 (NOT FOR MERGE) #13857
• apollo_l1_gas_price,apollo_l1_gas_price_config: move exchange_rate_decimals const to config #13881
• apollo_consensus_orchestrator: add SNIP-35 proposer-validator symmetry tests #13856
• apollo_consensus_orchestrator: add SNIP-35 module edge case tests #13855
• apollo_consensus_orchestrator,apollo_consensus_manager: route STRK/USD via L1GasPriceProvider #14161
• apollo_integration_tests,apollo_deployments: prime strk_to_usd_oracle overlays #14160
• apollo_l1_gas_price_types,apollo_l1_gas_price: expose get_strk_to_usd_rate #14159
• apollo_l1_gas_price: hold strk_to_usd oracle client + strk_to_usd_rate #14158
• apollo_l1_gas_price: parameterize ExchangeRateOracleClient by metric set #14199 👈 (View in Graphite)
• apollo_l1_gas_price_config,apollo_node: add strk_to_usd_oracle_config #14157
• apollo_consensus_orchestrator: add SNIP-35 fee_proposal validation #13819 : 1 other dependent PR (#13820 )
• apollo_consensus_orchestrator: include fee_proposal_fri in proposal commitment hash #13949
• apollo_starknet_client: read fee_proposal_fri from feeder gateway #13986
• apollo_consensus_orchestrator: wire SNIP-35 fee_proposal into cende blob #13985
• apollo_consensus_orchestrator: wire SNIP-35 fee_proposal into build_proposal #13818
• apollo_consensus_orchestrator,apollo_consensus_manager: move SNIP-35 bootstrap to pre-consensus #14061
• apollo_node_config: made validation only node hold full state #14122
• main

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[matanl-starkware]

@matanl-starkware reviewed 8 files and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on sirandreww-starkware).

[sirandreww-starkware]

@sirandreww-starkware made 6 comments.
Reviewable status: all files reviewed, 6 unresolved discussions (waiting on ShahakShama).

---

crates/apollo_consensus_orchestrator/src/metrics.rs line 39 at r1 (raw file):

        // The STRK/USD rate gauge (`snip35_strk_usd_rate`) plus its query
        // success/error/last-success-timestamp counters live in `apollo_l1_gas_price`,
        // owned by the `ExchangeRateOracleClient` that fetches the rate.

didn't you remove this?

Code quote:

        // The STRK/USD rate gauge (`snip35_strk_usd_rate`) plus its query
        // success/error/last-success-timestamp counters live in `apollo_l1_gas_price`,
        // owned by the `ExchangeRateOracleClient` that fetches the rate.

---

crates/apollo_consensus_orchestrator/src/sequencer_consensus_context.rs line 464 at r1 (raw file):

                Ok(rate) => {
                    // The oracle client publishes `snip35_strk_usd_rate` itself; consensus
                    // only consumes the value to compute `fee_target`.

Would remove these

Code quote:

                    // The oracle client publishes `snip35_strk_usd_rate` itself; consensus
                    // only consumes the value to compute `fee_target`.

---

crates/apollo_dashboard/src/panels/consensus.rs line 772 at r1 (raw file):

        "\"Failed to resolve query to\" OR \"Timeout when resolving query to\" OR \"Query failed \
         to join handle for timestamp\"",
    )

why log?

Code quote:

    .with_log_query(
        "\"Failed to resolve query to\" OR \"Timeout when resolving query to\" OR \"Query failed \
         to join handle for timestamp\"",
    )

---

crates/apollo_dashboard/src/panels/consensus.rs line 782 at r1 (raw file):

        PanelType::TimeSeries,
    )
    .with_log_query("Caching conversion rate for timestamp")

why log?

Code quote:

.with_log_query("Caching conversion rate for timestamp")

---

crates/apollo_dashboard/src/panels/consensus.rs line 789 at r1 (raw file):

        "Seconds Since Last Successful STRK→USD Rate Update",
        "The number of seconds since the last successful STRK→USD rate update (assuming there \
         was an update in the last 12 hours).",

why is this assumption here?

Code quote:

        "The number of seconds since the last successful STRK→USD rate update (assuming there \
         was an update in the last 12 hours).",

---

crates/apollo_l1_gas_price/src/metrics.rs line 67 at r1 (raw file):

            .finish()
    }
}

was this really needed? no default for metrics?

Code quote:

// Manual impl: `MetricGauge` / `MetricCounter` do not derive `Debug`,
// but the surrounding `ExchangeRateOracleClient` does. Printing the prom
// name of each metric is the only useful thing to surface.
impl std::fmt::Debug for ExchangeRateOracleMetrics {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("ExchangeRateOracleMetrics")
            .field("rate", &self.rate.get_name())
            .field("success_count", &self.success_count.get_name())
            .field("error_count", &self.error_count.get_name())
            .field("last_success_timestamp", &self.last_success_timestamp.get_name())
            .finish()
    }
}

[sirandreww-starkware]

@sirandreww-starkware resolved 3 discussions.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on ShahakShama).

[ShahakShama]

@ShahakShama made 3 comments.
Reviewable status: 6 of 8 files reviewed, 3 unresolved discussions (waiting on matanl-starkware and sirandreww-starkware).

---

crates/apollo_consensus_orchestrator/src/metrics.rs line 39 at r1 (raw file):

Previously, sirandreww-starkware (Andrew Luka) wrote…

didn't you remove this?

Done.

---

crates/apollo_consensus_orchestrator/src/sequencer_consensus_context.rs line 464 at r1 (raw file):

Previously, sirandreww-starkware (Andrew Luka) wrote…

Would remove these

Done.

---

crates/apollo_l1_gas_price/src/metrics.rs line 67 at r1 (raw file):

Previously, sirandreww-starkware (Andrew Luka) wrote…

was this really needed? no default for metrics?

no default

[sirandreww-starkware]

@sirandreww-starkware reviewed 8 files and all commit messages, made 1 comment, and resolved 3 discussions.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on ShahakShama).