QueryObserver

Sees the outcome of every query a gateway runs: the hook a host's metrics (9.x QueryMetricsObserver, wired by the host in 6.2c), logs (QueryLogObserver) and audit trail implement. A query ends in exactly one of onComplete, onError and onCancel; when audits is set, onAudit follows with its QueryAudit. A cross-tenant query is audited whatever the observers: its audit is logged at INFO (QueryAudit.CROSS_TENANT_LOGGER).

start observes the query of a QueryModel as a stage of work: its span and its time, from its admission to its end; the gateway ends the Observation it returns once the query ends, telling it the failure it ended with.

Inheritors