# IActivationWorkingSetObserver Methods

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.iactivationworkingsetobserver/)

## OnActive(IActivationWorkingSetMember) {#onactive-orleans-runtime-iactivationworkingsetmember-43409471}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.iactivationworkingsetobserver/methods/onactive-orleans-runtime-iactivationworkingsetmember-43409471/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Catalog/ActivationWorkingSet.cs#L264)

```csharp
public virtual void OnActive(IActivationWorkingSetMember member)
```

Called when an activation becomes active.

### Parameters

- `member` (`IActivationWorkingSetMember`)

## OnAdded(IActivationWorkingSetMember) {#onadded-orleans-runtime-iactivationworkingsetmember-84adf335}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.iactivationworkingsetobserver/methods/onadded-orleans-runtime-iactivationworkingsetmember-84adf335/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Catalog/ActivationWorkingSet.cs#L259)

```csharp
public virtual void OnAdded(IActivationWorkingSetMember member)
```

Called when an activation is added to the working set.

### Parameters

- `member` (`IActivationWorkingSetMember`)

## OnDeactivated(IActivationWorkingSetMember) {#ondeactivated-orleans-runtime-iactivationworkingsetmember-f5096c09}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.iactivationworkingsetobserver/methods/ondeactivated-orleans-runtime-iactivationworkingsetmember-f5096c09/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Catalog/ActivationWorkingSet.cs#L284)

```csharp
public virtual void OnDeactivated(IActivationWorkingSetMember member)
```

Called when an activation is deactivated.

### Parameters

- `member` (`IActivationWorkingSetMember`)

## OnDeactivating(IActivationWorkingSetMember) {#ondeactivating-orleans-runtime-iactivationworkingsetmember-56346626}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.iactivationworkingsetobserver/methods/ondeactivating-orleans-runtime-iactivationworkingsetmember-56346626/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Catalog/ActivationWorkingSet.cs#L279)

```csharp
public virtual void OnDeactivating(IActivationWorkingSetMember member)
```

Called when an activation starts deactivating.

### Parameters

- `member` (`IActivationWorkingSetMember`)

## OnEvicted(IActivationWorkingSetMember) {#onevicted-orleans-runtime-iactivationworkingsetmember-5cf51717}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.iactivationworkingsetobserver/methods/onevicted-orleans-runtime-iactivationworkingsetmember-5cf51717/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Catalog/ActivationWorkingSet.cs#L274)

```csharp
public virtual void OnEvicted(IActivationWorkingSetMember member)
```

Called when an activation is removed from the working set.

### Parameters

- `member` (`IActivationWorkingSetMember`)

## OnIdle(IActivationWorkingSetMember) {#onidle-orleans-runtime-iactivationworkingsetmember-1dd8bfe1}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.runtime/orleans.runtime.iactivationworkingsetobserver/methods/onidle-orleans-runtime-iactivationworkingsetmember-1dd8bfe1/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.Runtime/Catalog/ActivationWorkingSet.cs#L269)

```csharp
public virtual void OnIdle(IActivationWorkingSetMember member)
```

Called when an activation becomes idle.

### Parameters

- `member` (`IActivationWorkingSetMember`)