Stop emitting metrics the MCP dashboard no longer queries

[ChiragAgg5k]

The MCP Grafana dashboard (appwrite-labs/dashboards mcp.json) was curated down to six rows — Overview, Protocol & Messages, Tool Execution, Agentic & Token Metrics, Sessions & Connections, System Resources. This drops every instrument whose panels are gone, so we stop exporting series nothing reads:

Removed (with their record helpers, call sites, and tests):

• mcp_connection_total — Transport row removed; mcp_handshake_total{status="success"} remains the connection signal, so the initialize path now records handshakes only
• mcp_rate_limit_total / mcp_rate_limit_active — Rate Limiting row removed
• mcp_resource_accessed/errors/size/access_anomaly — Resource Access row removed
• http_requests_total / http_request_duration_seconds + HTTPMetricsMiddleware — HTTP Layer row removed
• Legacy Appwrite-specific metrics that were never on the new dashboard: mcp_appwrite_calls/call_duration/errors, mcp_write_confirmations, mcp_search_tools_*, mcp_search_docs_*, mcp_context_requests, mcp_auth_validations/duration, mcp_uploads/upload_bytes/upload_errors

Kept (everything mcp.json queries): tool calls/duration/errors/in-flight/result size, token usage (+per-call), handshakes, active sessions (+by client), session duration/disconnects, messages/latency/size, JSON-RPC errors, protocol versions, CPU/memory, mcp_server_info (dashboard variables).

The telemetry module docstring now states the contract: only metrics queried by the hosted dashboard are emitted — remove a panel there, drop its instrument here.

Behavior otherwise unchanged: error monitoring (Sentry) paths, write-confirmation gating, and the identity middleware are untouched.

Testing: ruff/black/pyright clean, 160 unit tests pass, Docker build passes, and the ASGI app smoke-boots (healthz 200, unauthenticated /mcp 401).

[greptile-apps]

Greptile Summary

This PR prunes the telemetry layer to match the curated Grafana dashboard, removing every metric instrument whose panel was dropped and establishing a client-name allowlist to bound client_id label cardinality. All removed call sites, record helpers, and tests are cleaned up consistently across the module.

• Metrics removed: mcp_connection_total, rate-limit gauges, resource-access counters, the full HTTP-layer middleware, and ~15 Appwrite-specific instruments that were never on the hosted dashboard — telemetry.py shrinks by ~150 lines with no retained references.
• Cardinality hardening added: _normalize_client_name now checks against a fixed KNOWN_MCP_CLIENTS allowlist (sorted longest-first for greedy prefix matching) and collapses anything unrecognized to "other", preventing client-controlled input from minting unbounded label values.
• Behavior preserved: SSRF validation, Sentry error capture, write-confirmation gating, and the record_handshake_failure path in RequireBearer are all untouched.

Confidence Score: 5/5

Safe to merge — removes unused instrumentation with no changes to request handling, auth, or business logic.

Every deleted metric has its call sites, record helpers, and tests removed consistently. The one new behavior — collapsing unknown client names to "other" — is additive cardinality protection and is well-covered by the new allowlist tests. No correctness-affecting paths were changed.

No files require special attention.

Important Files Changed

Filename	Overview
src/mcp_server_appwrite/telemetry.py	Removes ~150 lines of unused metric instruments and record helpers; adds allowlist-based client name normalization to bound client_id label cardinality.
src/mcp_server_appwrite/constants.py	Adds KNOWN_MCP_CLIENTS allowlist tuple; purely additive, no logic changes.
src/mcp_server_appwrite/auth.py	Removes all telemetry.record_auth(...) call sites and the import telemetry / timing boilerplate; auth logic itself is unchanged.
src/mcp_server_appwrite/http_app.py	Removes HTTPMetricsMiddleware class and its registration; simplifies the unauthenticated-request branch; drops unused import time; record_handshake_failure call is correctly retained.
src/mcp_server_appwrite/operator.py	Drops telemetry for context requests, search-tools queries, and write confirmations; simplifies the write-guard conditional — logic is equivalent.
src/mcp_server_appwrite/server.py	Removes record_appwrite_call, record_upload*, and record_resource_access call sites; Sentry error-capture paths and SSRF validation logic are untouched.
src/mcp_server_appwrite/docs_search.py	Drops record_search_docs calls; renames unused embedding_duration_s return value to _embedding_duration_s; search logic is unchanged.
tests/unit/test_telemetry.py	Removes tests for deleted helpers; adds new tests for allowlist enforcement (test_unknown_client_names_collapse_to_other, test_unknown_client_sessions_are_labeled_other); updated connection dedupe test aligns with handshake-only counting.
tests/unit/test_http_app.py	Updates MCPIdentityMiddleware test to assert on mcp.handshake (not mcp.connection); assertions are correct and complete.

_{Reviews (2): Last reviewed commit: "(fix): bound client_id label values to a..." | Re-trigger Greptile}

[ChiragAgg5k]

Added a second commit: client_id label values are now bounded by a KNOWN_MCP_CLIENTS allowlist in constants.py (exact or prefixed match, longest first) — unrecognized client names collapse to other, so a caller can't mint arbitrary series on the Active Sessions by Client panel.