NewExemplarLabelsPosCache creates a cache of map[metric_name]LabelPositions where LabelPositions is map[LabelName]LabelPosition.

Cache is thread-safe.

Make the cache size the same as the metric size, assuming every metric has an exemplar.

this seems like a good default size for /active/ series.

(metric, label key-pair) -> (label id,label position) cache Used when creating series to avoid DB calls for labels Each label position is unique for a specific metric, meaning that one label can have different position for different metrics.

MetricNameCache stores and retrieves metric table names in an in-memory cache.

MetricCache provides a caching mechanism for metric table names.

SeriesCache is a cache of model.Series entries.