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symfonic.core.observability.metrics_store_factory

metrics_store_factory

METRICS_STORE identifier -> a concrete backend.

The resolution table only: none, postgres, mongo, or an adopter's dotted path. It is separated from :mod:symfonic.core.observability.metrics_store -- which owns the protocols, the buffered sink, and the process-wide hook -- because this is the one part that grows a branch per backend, and the optional-extra import guards belong next to the branch that needs them.

make_metrics_store 

make_metrics_store(identifier: str | None, *, postgres_session_factory: Any = None, mongo_database_factory: Any = None, mongo_retention_days: int = 90) -> MetricsStore | None

Resolve a METRICS_STORE identifier to a concrete backend.

none / "" → None (in-memory collector only, today's default). postgres → :class:PostgresMetricsStore (needs postgres_session_factory + symfonic-core[postgres]). mongo → :class:MongoMetricsStore (needs mongo_database_factory + symfonic-core[mongodb]). A dotted path (my_pkg.mod:MyStore or my_pkg.mod.MyStore) → the adopter's zero-arg-constructible MetricsStore.

Raises ValueError with a pip install hint on a missing extra and on an unknown identifier, so misconfiguration fails loudly at startup.

Source code in src/symfonic/core/observability/metrics_store_factory.py 
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def make_metrics_store(
    identifier: str | None,
    *,
    postgres_session_factory: Any = None,
    mongo_database_factory: Any = None,
    mongo_retention_days: int = 90,
) -> MetricsStore | None:
    """Resolve a ``METRICS_STORE`` identifier to a concrete backend.

    ``none`` / ``""`` → ``None`` (in-memory collector only, today's default).
    ``postgres`` → :class:`PostgresMetricsStore` (needs ``postgres_session_factory``
    + ``symfonic-core[postgres]``). ``mongo`` → :class:`MongoMetricsStore`
    (needs ``mongo_database_factory`` + ``symfonic-core[mongodb]``). A dotted
    path (``my_pkg.mod:MyStore`` or ``my_pkg.mod.MyStore``) → the adopter's
    zero-arg-constructible ``MetricsStore``.

    Raises ``ValueError`` with a ``pip install`` hint on a missing extra and
    on an unknown identifier, so misconfiguration fails loudly at startup.
    """
    raw = (identifier or "").strip()
    if raw == "" or raw.lower() == "none":
        return None
    low = raw.lower()

    if low == "postgres":
        if postgres_session_factory is None:
            raise ValueError(
                "METRICS_STORE=postgres requires a postgres_session_factory",
            )
        try:
            from symfonic.core.observability.postgres_metrics_store import (  # noqa: PLC0415
                PostgresMetricsStore,
            )
        except ImportError as exc:  # pragma: no cover - exercised via extra
            raise ValueError(
                "METRICS_STORE=postgres requires SQLAlchemy: "
                "pip install 'symfonic-core[postgres]'",
            ) from exc
        return PostgresMetricsStore(postgres_session_factory)

    if low in ("mongo", "mongodb"):
        if mongo_database_factory is None:
            raise ValueError(
                "METRICS_STORE=mongo requires a mongo_database_factory",
            )
        try:
            from symfonic.core.observability.mongo_metrics_store import (  # noqa: PLC0415
                MongoMetricsStore,
            )
        except ImportError as exc:  # pragma: no cover - exercised via extra
            raise ValueError(
                "METRICS_STORE=mongo requires motor: "
                "pip install 'symfonic-core[mongodb]'",
            ) from exc
        return MongoMetricsStore(
            mongo_database_factory, retention_days=mongo_retention_days,
        )

    if ":" in raw or "." in raw:
        cls = _import_dotted(raw)
        return cls()

    raise ValueError(
        f"unknown METRICS_STORE {raw!r}; expected 'none', 'postgres', "
        "'mongo', or a dotted path 'pkg.module:Class'",
    )