NLB Connection Tracking and Load Balancing
Applies To: Windows Server 2008
The Network Load Balancing (NLB) driver on the host tracks connections to maintain client/network affinity configured on the NLB cluster. If the driver is not functioning properly, NLB may not be able to track TCP connections or may experience load distribution errors.
Events
| Event ID | Source | Message |
|---|---|---|
Microsoft-Windows-NLB |
NLB cluster [%2]: The NLB driver could not allocate enough memory resources to perform driver operations. Close all programs on this cluster host that might be consuming memory and rebind NLB to the adapters. If this problem persists, you might need to add additional memory (RAM) to this host. | |
Microsoft-Windows-NLB |
NLB cluster [%2]: The maximum number of actively serviced connections that could be tracked by NLB is reached. Although NLB will still accept new connections, it will not track the connection state until other connections are closed. This might result in breaking the affinity maintained by the driver during the connection. To resolve this issue, add more hosts to the cluster and/or increase the %3 value under the HKLM\SYSTEM\CurrentControlSet\Services\WLBS\Parameters\Interface\{GUID} key in the registry. | |
Microsoft-Windows-NLB |
NLB cluster [%2]: NLB can't track TCP connections because it was unable to open the TCP connection callback object. Although NLB will still accept new connections, it will not track the connection state until this is resolved. This might result in breaking the affinity maintained by the driver during the connection. To resolve this issue, try to unbind then rebind NLB to the adapters. | |
Microsoft-Windows-NLB |
NLB cluster [%2]: A load distribution error was detected during convergence. This might result in client traffic not being handled, general traffic errors, or connections being reset. To fix the error, restart the cluster by typing 'nlb reload' and then 'nlb start' at a command prompt. | |
Microsoft-Windows-NLB |
NLB cluster [%2]: NLB failed to register as a WMI provider. As a result, it will not be able to notify applications that are listening for WMI events of any changes in the NLB driver. Using Control Panel or Device Manager, disable and re-enable the network adapter before attempting to bind NLB to the adapter. |