High Availability Setup for Introscope Enterprise Manager

High availability is typically requested for the MoM of an Enterprise Manager (EM) cluster, but can also be implemented for a stand-alone EM. HA for collectors is less common because the assumption is that other collectors take over the load of a failing collector.

There are two approaches to achieve high availability of the EM:

  1. EM Hot Failover
  2. "standard" approach based on HA software

EM Hot Failover

This solution is defined by Introscope and relies on features built into the Enterprise Manager. Two EMs are active at the same time and they negotiate which of them should be responsible for alerts etc. The setup is described in the Introscope Administration Guide (Administrating → Configure Enterprise Manager → Configure Enterprise Managers and Clusters → Use Enterprise Manager Failover, external link). Switching between the EMs relies on DNS changes. Unfortunately this approach cannot be used in combination with SAP Solution Manager since the SMDAgents responsible for administrating the EM are not capable of supporting this.

Standard Approach based on HA Software

The standard approach is to install services on a logical host and to switch this logical host between different physical hosts using some kind of HA software. This is supported by diagnostics agents and can also be used for Enterprise Managers. In comparison to the EM Hot Failover approach this approach causes the additional delay of starting the EM.

Prerequisites

  1. A clustering / high availability solution is installed with physical hosts phostA, phostB
  2. A switch over group that should control the Introscope EM is defined that contains a logical server name emhost (or emhost.my.domain) and an associated IP address.
  3. Diagnostics agents are installed on both physical hosts phostA, phostB
  4. The agents on-the-fly feature is enabled for both agents on phostA and phostB. emhost is one of the logical host names that are covered by the agents. See diagnostics agents and HA for more details.

Introscope Enterprise Manager Setup

The following steps refer to Microsoft Cluster Services (MSCS) as HA solution. If needed adapt the procedure to your solution.

  1. Create a Cluster Disc (shared volume) in the switch over group in MSCS. Let's assume this is Windows drive S: and we plan to install into folder S:\introscope.
  2. Ensure that the diagnostics agent has read and write permission to this file system / folder. Typically this means that user SapServiceDAA (for diagnostics agent sid DAA) needs this permission. The share /saploc is not needed.
  3. Install the EM on phostA into folder S:\introscope. To change the target installation folder edit installer.properties and set USER_INSTALL_DIR=S:\introscope. Do not forget to install the management modules.
  4. Check that the installation was successful and that the Windows service Introscope Enterprise Manager can be started. Check that the EM can be reached via http://emhost.my.domain:8081/webview.
  5. Add the Windows service Introscope Enterprise Manager to the switch over group cluster resource type service
  6. Take the cluster resource offline
  7. Switch the cluster resource to the other node phostB. The S: drive should now be available on phostB.
  8. On host phostB create the Windows Service for the EM:
    1. Open a command prompt with Administrator permission
    2. go to folder S:\introscope\bin and issue the command EMCtrl64 register (for the 64 bit version; for 32bit use EMCtrl32 register)
  9. Take the cluster resource online
  10. Check that the Introscope EM can be reached via http://emhost.my.domain:8081/webview no matter whether emhost is currently on phostA or phostB.

Connect EM to SAP Solution Manager

To connect the EM to SAP Solution Manager, please follow the steps below:

  1. Go to Solution Manager Infrastructure Preparation, Step 4: Define CA Introscope. Activate Edit mode.
  2. Click Discover Introscope EM.
    1. As installation path enter the location on the shared drive.
      S:\introscope.
    2. As diagnostics agent choose the agent with the logical host name emhost.
    3. Click Discover installation.
    4. As a result the new EM should show up as line in the table.
  3. Edit the EM host name in the table such that the logical host name emhost is displayed here.
  4. Change the Client Host to also contain the logical host name emhost
  5. Click User Management to set the connection user to the EM.