**Description**


It would be great if the metrics we publish in Airflow change to include TAGs for "variable" parts of those (such as dag_id, task_id, pool name) rather than being part of the metrics.

See here: https://airflow.apache.org/docs/1.10.12/metrics.html, https://airflow.readthedocs.io/en/latest/logging-monitoring/metrics.html  - those variable parts should be tags.

We might consider to change those metrics by default in 2.0 and possibly introduce a backport in 1.10.13 to allow people to migrate.


**Use case / motivation**

Having the variable parts of the metrics makes it really difficult to aggregate the metrics. Seems that statsd python library does not support tags, but there are possible solutions by installing extensions:

https://stackoverflow.com/questions/49852654/sending-statsd-metrics-with-tags-from-python-client

**Related Issues**

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return self.execution_date
    def get_state(self):
        return self._state
    def set_state(self, state: DagRunState):
        if state not in State.dag_states:
            raise ValueError(f"invalid DagRun state: {state}")
        if self._state != state:
            self._state = state
            self.end_date = timezone.utcnow() if self._state in State.finished else None
            if state == State.QUEUED:
                self.queued_at = timezone.utcnow()
    @declared_attr
    def state(self):
        return synonym("_state", descriptor=property(self.get_state, self.set_state))
    @provide_session
    def refresh_from_db(self, session: Session = NEW_SESSION) -> None:
        """
        Reloads the current dagrun from the database
        :param session: database session
        """
        dr = session.query(DagRun).filter(DagRun.dag_id == self.dag_id, DagRun.run_id == self.run_id).one()
        self.id = dr.id
        self.state = dr.state
    @classmethod
    @provide_session
    def active_runs_of_dags(cls, dag_ids=None, only_running=False, session=None) -> dict[str, int]: