# Functions
NewOperationStartTimeCache creates a operation timestamp cache.
RecordMetric records either an error count metric or a latency metric if there exists a start timestamp entry in the cache.
RecordVolumeOperationErrorMetric records error count into metric volume_operation_total_errors for provisioning/deletion operations.
Register all metrics for pv controller.
# Structs
OperationStartTimeCache concurrent safe cache for operation start timestamps.