metrics

type Metrics struct {
	Registry *prometheus.Registry
	// Query metrics
	QueriesTotal     *prometheus.CounterVec
	QueryDuration    *prometheus.HistogramVec
	QueryRowsScanned *prometheus.CounterVec
	QueryBytesRead   prometheus.Counter
	ActiveQueries    prometheus.Gauge

	// Scanner metrics
	FilesScanned      prometheus.Counter
	FilesPruned       prometheus.Counter
	RowGroupsScanned  prometheus.Counter
	RowGroupsPruned   prometheus.Counter
	PartitionsScanned prometheus.Counter
	PartitionsPruned  prometheus.Counter

	// Worker metrics
	WorkerTasks        *prometheus.CounterVec
	WorkerTaskDuration *prometheus.HistogramVec
	WorkerActive       prometheus.Gauge
	WorkerMemory       prometheus.Gauge

	// Coordinator metrics
	RegisteredWorkers prometheus.Gauge

	// Pipeline metrics
	BatchesProcessed prometheus.Counter
	RowsOutput       prometheus.Counter

	// Memory/Spill metrics
	SpillEvents       prometheus.Counter
	SpillBytesWritten prometheus.Counter
	MemoryBudgetBytes prometheus.Gauge
	MemoryUsedBytes   prometheus.Gauge

	// Cache metrics
	CacheHits   prometheus.Counter
	CacheMisses prometheus.Counter
	CacheBytes  prometheus.Gauge

	// Object-store circuit breaker. Labelled by operation class (read /
	// write / delete) because the classes are independent breakers: an
	// operator needs to see that DELETEs are tripping without concluding
	// that reads are (ADR-0028).
	CircuitBreakerOpened *prometheus.CounterVec
}