# ZooKeeperBasedMembershipTable.CleanupDefunctSiloEntriesAsync(DateTimeOffset, CancellationToken)

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.clustering.zookeeper/orleans.runtime.membership.zookeeperbasedmembershiptable/) | [Methods](/orleans/docs/api/csharp/microsoft.orleans.clustering.zookeeper/orleans.runtime.membership.zookeeperbasedmembershiptable/methods/)

[Source](https://github.com/dotnet/orleans/blob/8bc9fd244427351ad24ccc039a9e7642a42c1cc4/src/Orleans.Clustering.ZooKeeper/ZooKeeperBasedMembershipTable.cs#L602-L603)

```csharp
public Task CleanupDefunctSiloEntriesAsync(DateTimeOffset beforeDate, CancellationToken cancellationToken = default(CancellationToken))
```

Removes dead silo entries whose last known update precedes `beforeDate`.

### Parameters

- `beforeDate` (`DateTimeOffset`): The exclusive upper bound for the last update time of entries to delete.
- `cancellationToken` (`CancellationToken`): A token which cancels the operation.

### Returns

A task representing the cleanup operation.