# InMemory Persistence
The InMemory persistence service provides volatile storage, i.e., it is cleared on shutdown.
Because of that, the restoreOnStartup strategy is not supported for this service.
The main use case is to store data that is needed during runtime, e.g., temporary storage of forecast data that is retrieved from a binding.
The default strategy for this service is forecast.
Unlike other persistence services, you MUST add a configuration, otherwise no data will be persisted.
To avoid excessive memory usage, it is recommended to persist only a limited number of items and use a strategy that stores only data that is actually needed.
The service has a global configuration option maxEntries to limit the number of data points per item; the default value is 512.
When the number of data points is reached and a new value is persisted, the oldest (by timestamp) value will be removed.
A maxEntries value of 0 disables automatic purging.