# OpcSubscriptionDiagnostics Members
> Reference: Provides diagnostic information about the operations performed and activities recognized on a OpcSubscription.
- Type
- OpcSubscriptionDiagnostics
- Namespace
- Opc.UaFx.Server
- Assembly
- Opc.UaFx.Advanced.dll
- Package
- Opc.UaFx.Advanced v2.59.0
## Properties
### CurrentKeepAliveCount
Gets the current keep-alive counter of the subscription, i.e. the number of publishing intervals since the subscription has last sent a message.
```csharp
public int CurrentKeepAliveCount { get; }
```
```vbnet
Public ReadOnly Property CurrentKeepAliveCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The current value of the keep-alive counter.
### CurrentLifetimeCount
Gets the current lifetime counter of the subscription, i.e. the number of consecutive publishing intervals in which the subscription has waited for a publish request of the client.
```csharp
public int CurrentLifetimeCount { get; }
```
```vbnet
Public ReadOnly Property CurrentLifetimeCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The current value of the lifetime counter. The subscription expires when it reaches [MaxLifetimeCount](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcsubscriptiondiagnostics/members#maxlifetimecount).
### DataChangeNotificationsCount
Gets the number of data change notifications the subscription has sent.
```csharp
public int DataChangeNotificationsCount { get; }
```
```vbnet
Public ReadOnly Property DataChangeNotificationsCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of data change notifications.
### DisableCount
Gets the number of times publishing has been disabled for the subscription.
```csharp
public int DisableCount { get; }
```
```vbnet
Public ReadOnly Property DisableCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of times publishing has been disabled.
### DisabledMonitoredItemCount
Gets the number of monitored items of the subscription whose monitoring mode is disabled.
```csharp
public int DisabledMonitoredItemCount { get; }
```
```vbnet
Public ReadOnly Property DisabledMonitoredItemCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of disabled monitored items.
### DiscardedMessageCount
Gets the number of messages of the subscription which the server has discarded.
```csharp
public int DiscardedMessageCount { get; }
```
```vbnet
Public ReadOnly Property DiscardedMessageCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of discarded messages. The server does not maintain this counter, therefore the value is currently always 0.
### EnableCount
Gets the number of times publishing has been enabled for the subscription.
```csharp
public int EnableCount { get; }
```
```vbnet
Public ReadOnly Property EnableCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of times publishing has been enabled.
### EventNotificationsCount
Gets the number of event notifications the subscription has sent.
```csharp
public int EventNotificationsCount { get; }
```
```vbnet
Public ReadOnly Property EventNotificationsCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of event notifications.
### EventQueueOverFlowCount
Gets the number of times the event queue of a monitored item of the subscription has overflowed.
```csharp
public int EventQueueOverFlowCount { get; }
```
```vbnet
Public ReadOnly Property EventQueueOverFlowCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of event queue overflows. The server does not maintain this counter, therefore the value is currently always 0.
### LatePublishRequestCount
Gets the number of publishing intervals which have elapsed while the subscription was waiting for a publish request of the client.
```csharp
public int LatePublishRequestCount { get; }
```
```vbnet
Public ReadOnly Property LatePublishRequestCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of such publishing intervals.
### MaxKeepAliveCount
Gets the maximum keep-alive count of the subscription.
```csharp
public int MaxKeepAliveCount { get; }
```
```vbnet
Public ReadOnly Property MaxKeepAliveCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of publishing intervals without notifications after which the subscription sends a keep-alive message.
### MaxLifetimeCount
Gets the maximum lifetime count of the subscription.
```csharp
public int MaxLifetimeCount { get; }
```
```vbnet
Public ReadOnly Property MaxLifetimeCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of publishing intervals without a publish request of the client after which the subscription expires.
### MaxNotificationsPerPublish
Gets the maximum number of notifications the subscription sends in one message.
```csharp
public int MaxNotificationsPerPublish { get; }
```
```vbnet
Public ReadOnly Property MaxNotificationsPerPublish As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The maximum number of notifications per message.
### ModifyCount
Gets the number of times the subscription has been modified.
```csharp
public int ModifyCount { get; }
```
```vbnet
Public ReadOnly Property ModifyCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of modifications.
### MonitoredItemCount
Gets the number of monitored items of the subscription.
```csharp
public int MonitoredItemCount { get; }
```
```vbnet
Public ReadOnly Property MonitoredItemCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of monitored items.
### MonitoringQueueOverflowCount
Gets the number of times the queue of a monitored item of the subscription has overflowed.
```csharp
public int MonitoringQueueOverflowCount { get; }
```
```vbnet
Public ReadOnly Property MonitoringQueueOverflowCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of queue overflows.
### NextSequenceNumber
Gets the sequence number of the next message of the subscription.
```csharp
public int NextSequenceNumber { get; }
```
```vbnet
Public ReadOnly Property NextSequenceNumber As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The next sequence number.
### NotificationsCount
Gets the number of notifications the subscription has sent.
```csharp
public int NotificationsCount { get; }
```
```vbnet
Public ReadOnly Property NotificationsCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of notifications.
### PublishRequestCount
Gets the number of publish requests the subscription has processed.
```csharp
public int PublishRequestCount { get; }
```
```vbnet
Public ReadOnly Property PublishRequestCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of publish requests.
### RepublishMessageCount
Gets the number of messages the subscription has sent again on a republish request.
```csharp
public int RepublishMessageCount { get; }
```
```vbnet
Public ReadOnly Property RepublishMessageCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of messages sent again.
### RepublishMessageRequestCount
```csharp
public int RepublishMessageRequestCount { get; }
```
```vbnet
Public ReadOnly Property RepublishMessageRequestCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
### RepublishRequestCount
Gets the number of republish requests the subscription has received.
```csharp
public int RepublishRequestCount { get; }
```
```vbnet
Public ReadOnly Property RepublishRequestCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of republish requests.
### TransferredToAlternativeClientsCount
Gets the number of times the subscription has been transferred to a session of another client.
```csharp
public int TransferredToAlternativeClientsCount { get; }
```
```vbnet
Public ReadOnly Property TransferredToAlternativeClientsCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of such transfers. The server does not maintain this counter, therefore the value is currently always 0.
### TransferredToSameClientCount
Gets the number of times the subscription has been transferred to another session of the same client.
```csharp
public int TransferredToSameClientCount { get; }
```
```vbnet
Public ReadOnly Property TransferredToSameClientCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of such transfers. The server does not maintain this counter, therefore the value is currently always 0.
### TransferRequestCount
Gets the number of requests to transfer the subscription to another session.
```csharp
public int TransferRequestCount { get; }
```
```vbnet
Public ReadOnly Property TransferRequestCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of transfer requests. The server does not maintain this counter, therefore the value is currently always 0.
### UnacknowledgedMessageCount
Gets the number of messages of the subscription which the client has not yet acknowledged.
```csharp
public int UnacknowledgedMessageCount { get; }
```
```vbnet
Public ReadOnly Property UnacknowledgedMessageCount As Integer
```
**Property value**
[Int32](https://learn.microsoft.com/dotnet/api/system.int32)
The number of unacknowledged messages.