Deployment Guide for IM and Presence Service on Cisco Unified Communications Manager, Release 9.0(1)
Performing an IM and Presence multinode deployment
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IM and Presence Service Multinode Deployment Configuration

IM and Presence Service Multinode Deployment Configuration

Cisco Replication Watcher Service

The Cisco Replication Watcher monitors IDS replication state on IM and Presence Service. Other IM and Presence Service services are dependent on the Cisco Replication Watcher service. These dependent services use the Cisco Replication Watcher service to delay startup until such time as IDS replication is in a stable state.

On the subscriber nodes, the Cisco Replication Watcher service delays the startup of feature services until IDS replication is successfully established. The Cisco Replication Watcher service only delays the startup of feature services on the problem subscriber node in a cluster, it will not delay the startup of feature services on all subscriber nodes due to one problem node. For example, if IDS replication is successfully established on node1 and node2, but not on node3, the Cisco Replication Watcher service allows feature services to start on node1 and node2, but delays feature service startup on node3.

The Cisco Replication Watcher service behaves differently on the IM and Presence database publisher node. It only delays the startup of feature services until a timeout expires. When the timeout expires, it allows all feature services to start on the publisher node even if IDS replication is not successfully established.

The Cisco Replication Watcher service generates an alarm when it delays feature service startup on a node. It then generates a notification when IDS replication is successfully established on that node.

The Cisco Replication Watcher service impacts both a fresh multinode installation, and a software upgrade procedure. Both will only complete when the publisher node and subscriber nodes are running the same IM and Presence Service release, and IDS replication is successfully established on the subscriber nodes.

To check the status of the IDS replication on a node either:

  • Use this CLI command: utils dbreplication runtimestate
  • Use the Cisco Unified IM and Presence Reporting Tool. The "IM and Presence Database Status" report displays a detailed status of the cluster.

Multinode Update Configuration After Deployment

Add New Node

Follow this procedure if you need to add new nodes after a multinode deployment is running.

You can create the new node in your topology before you install the node, specifically before you install the IM and Presence Service software on the new node. However, you cannot assign the new node to a subcluster before you install IM and Presence Service software on the new node.

Restrictions

Your hardware must comply with the multinode hardware recommendations.

Procedure
    Step 1   Create a new subcluster in system topology management GUI (if required).
    Step 2   Create a new node in system topology management GUI.
    Step 3   Install the IM and Presence Service software on the new node.

    See the Installing Cisco Unified Communications Manager, Release 9.0(1) for the installation procedure.

    Step 4   Assign the node to the subcluster (if required).
    Note   

    Before you assign or move a node to a subcluster, check the following

    • From System troubleshooter page, verify that the Cisco Replication Watcher service is running on all nodes.
    • On the Network services screen in Cisco Unified IM and Presence Serviceability (on the subscriber node), verify that all IM and Presence Service services are running.

    IM and Presence assigns the node to the cluster, but the node will not receive traffic until you assign users to it.

    Step 5   Turn on High Availability in the subclusters as required.
    Step 6   Assign users from other nodes to the new node as required.

    Expand Cluster

    Restrictions

    • Your hardware must comply with the multinode hardware recommendations.
    • Cisco recommends that you perform any node movements that involve you unassigning or moving a large numbers of users at off peak times. Such large operations can adversely impact performance.
    Procedure
      Step 1   Create the new subcluster(s) in system topology management GUI (if required).
      Step 2   Create the new nodes in system topology management GUI.
      Step 3   Install each new node.
      Step 4   Assign the nodes to the (new) subclusters.
      Note   

      Before you assign or move a node to a subcluster, check the following

      • From System troubleshooter page, verify that the Cisco Replication Watcher service is running on all nodes.
      • On the Network services screen in Cisco Unified IM and Presence Serviceability (on the subscriber node), verify that all IM and Presence Service services are running.
      Step 5   Turn on High Availability in the subclusters as required.
      Step 6   Once all the nodes are online, assign users to the new nodes using the following user assignment options:
      1. Using the Find User Assignment feature, unassign selected users from each node, and use the User Assignment Mode parameter to reassign new users to new subcluster(s) and nodes.
      2. Using the Find User Assignment feature, manually move users to new nodes.
      3. Unassign all users, and then reassign the users to the cluster using the appropriate User Assignment Mode parameter setting for the whole cluster.
        Tip   

        You must turn off High Availability in a subcluster before you move or unassign a node in that subcluster.


      Remove Node

      Follow this procedure if you need to safely remove an IM and Presence Service node from a subcluster.


      Note


      This procedure removes subscriber nodes only. Publisher nodes cannot be removed.



      Caution


      Removing a node will cause a service interruption to users on the remaining node(s) in the subcluster. This procedure should only be performed during a maintenance window.


      Procedure
        Step 1   Select Cisco Unified CM IM and Presence Administration > System > Cluster Topology.
        Step 2   Turn off High Availability if it is enabled.
        Step 3   Unassign or move all users from the node that you want to remove.
        Step 4   To remove the node from its subcluster, drag the node icon to the Available Nodes pane. Select OK when a warning dialog box indicates that services in the subcluster will be restarted as a result of removing the node.
        Step 5   Delete the node you have unassigned from the Cluster Topology page. Select OK when a warning dialog box indicates this action can only be undone by performing a fresh installation.
        Step 6   Shut down the host VM or server for the node you have unassigned.
        Step 7   Remove the Application Server entry on Cisco Unified Communications Manager for the node you have unassigned.

        Multinode Deployment Troubleshooting

        Monitor Multinode System

        Restriction

        If you need to add hardware to your multinode deployment, the hardware must comply with the multinode hardware recommendations.

        Procedure
          Step 1   Use the IM and Presence Real-Time Monitoring Tool (RTMT) tool to monitor the CPU and memory usage of each IM and Presence Service node in the cluster.
          Step 2   Use these guidelines to determine if you need additional hardware:

          Deployment Model

          Recommendation

          No High Availability or Balanced Non-Redundant High Availability

          If the CPU reaches more than 70% capacity for a sustained period on any IM and Presence Service node, we recommend that you add hardware resources to your deployment.

          Balanced Redundant High Availability

          If the CPU reaches more than 35% capacity over a sustained period on either IM and Presence Service node in the subcluster, we recommend that you add hardware resources to your deployment.

          Active/Standby High Availability

          If the CPU reaches more than 70% capacity for a sustained period of time on the active IM and Presence Service node, we recommend that you add hardware resources to your deployment.


          Resolve Hardware Problem

          Follow this procedure if there is a problematic node, or some general hardware failure.

          Restrictions

          If you need to add hardware to your multinode deployment, the hardware must comply with the multinode hardware recommendations.

          Procedure
            Step 1   Create a new node in system topology management GUI.
            Step 2   Perform a fresh installation on this node.
            Step 3   Unassign the users from the problematic node.
            Step 4   Stop all services on the problematic node.
            Step 5   Unassign the problematic node.
            Step 6   Assign the new node to the subcluster, replacing the problematic node.
            Step 7   Reassign the unassigned users to the new node.
            Step 8   Delete the problematic node.
            Step 9   Activate all services on the new node.

            Troubleshooting Tip

            You must turn off High Availability in a subcluster before you move or unassign a node in that subcluster.