# ChronologicalEvictionStrategy.PurgeObservable

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.chronologicalevictionstrategy/) | [Properties](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.chronologicalevictionstrategy/properties/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Streaming/Common/PooledCache/ChronologicalEvictionStrategy.cs)

```csharp
public IPurgeObservable PurgeObservable
```

Gets the [IPurgeObservable](/orleans/docs/api/csharp/microsoft.orleans.streaming/orleans.providers.streams.common.ipurgeobservable/), which is implemented by the cache to do purge related actions and invoked by the eviction strategy.