# ClusterMembershipOptions.DefunctSiloCleanupPeriod

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.configuration.clustermembershipoptions/) | [Properties](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.configuration.clustermembershipoptions/properties/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Core/Configuration/Options/ClusterMembershipOptions.cs)

```csharp
public TimeSpan? DefunctSiloCleanupPeriod
```

Gets or sets a value indicating whether defunct silo entries older than [ClusterMembershipOptions](/orleans/docs/api/csharp/microsoft.orleans.core/orleans.configuration.clustermembershipoptions/) are removed. Cleanup is attempted when membership changes are observed and the current membership snapshot contains expired non-active entries, or when this period has elapsed since the last cleanup call. Set this value to `null` to disable expiration-based cleanup.

### Value

Expiration-based cleanup is enabled by default.