Maintaining Continuous Failover Cluster Operation

You can perform different operations after a failure of one of the members of a DS License Server cluster, without having to stop the cluster.

During a hardware failure involving a member of a DS License Server failover cluster, the cluster remains active. You do not need to stop the cluster to replace the failed member by a new one.

Note: If one of the three members of a failover cluster goes down, the failover itself remains active and can continue to serve licensing clients without interruption. The status of the failover is yellow in the License Administration Tool.

Even if the replacement is planned, the failover cluster being down even only for a few minutes can impact operations. You can perform the following actions for the failed member, to restore the failover status to green, without stopping the failover cluster:

  • replace a failover member
  • change the hostname of a failover member
  • replace the network card hosting the computerID of a failover member
  • repair a corrupted license server database of a failover member.
Note: Once a computer is excluded from a failover cluster, it has to be reinitialized to be re-used as a standalone server or as a member of a failover (even if it is the same as before).

This task shows you how to:

Replace a Failover Member

Before you begin: In the following scenario, let us assume you have a failover cluster with the following three cluster members, M1, M2 and M3:
  • M1: iclin1plp
  • M2: icaix1plp
  • M3: iclin3plp

Let us assume member M1 is broken and must be replaced with member M4.

  1. Install a DS License Server from scratch on member M4.

    In case an administration port different from the default one (4084) has been set for the cluster, do specify this particular number when installing from scratch.

  2. Do not configure M4.

    In particular, do not set passwords and do not set failover mode. Any passwords, the failover mode and the other settings will be automatically transferred in the next steps.

  3. Obtain replacement failover license keys for the computer IDs M2, M3 and M4.
  4. From failover member M2, start the License Administration Tool.
  5. In the Server Configuration dialog box for your cluster, click ... after member M1:

    The Modify Cluster Member dialog box appears.

  6. Select the option Replace computer with and enter the name of M4, for example nuq32plp, which will replace iclin1plp computer , as illustrated below:



    Then, click OK.

    The following warning appears:

    Warning: Enrolled licenses will be invalidated within 24 hours.
You should be ready after this operation to enroll a full set of licenses.
Do you want to proceed?

    Click Yes.

    Your modified cluster now contains the following members:

    • M4: nuq32plp
    • M2: icaix1plp
    • M3: iclin3plp

  7. Enroll new licenses generated for the cluster nuq32plp-icaix1plp-iclin3plp.

    New cluster licenses are required because one of the three computerIDs in the failover cluster has changed. For practical reasons, we strongly recommend that you obtain the new licenses BEFORE changing the computerID of a cluster member.

    Note: If two members are active, the failover cluster remains operational. When one computerID of the failover is changed, the cluster remains up but the old licenses are considered still valid for a maximum duration of 24 hours only. The new licenses containing the replacement computerID must be enrolled during this 24-hour period. Obtaining the new licenses before is critical.

    After enrolling the new licenses, your new cluster licenses are Active and users-licenses associations are kept the same as before:



    At any time during these steps, licensing clients were able to receive licenses.

Rename a Member

Before you begin: In the following scenario, let us assume you have a failover cluster with the following three cluster members, M1, M2 and M3:
  • M1: icwvc1plp
  • M2: icaix1plp
  • M3: icw8s4plp

Let us assume you need to rename M1 from icwvc1plp to icw7c1plp.

  1. Stop failover cluster member M1 icwvc1plp.
  2. Rename M1 and restart the computer.
  3. Install a DS License Server from scratch on member M1.

    In case an administration port different from the default one (4084) has been set for the cluster, do specify this particular number when installing from scratch.

  4. Do not configure M1.

    In particular, do not set passwords and do not set failover mode. Any passwords, the failover mode and the other settings will be automatically transferred in the next steps.

  5. From failover member M2, start the License Administration Tool.
  6. In the Server Configuration dialog box for your cluster, click the ... after member M1:



    The Modify Cluster Member dialog box appears.

  7. Select the option Change computer name and enter the name of computer icw7c1plp as illustrated below:



    Then, click the OK.

    Your modified cluster now contains the following members:

    • M1: icw7c1plp
    • M2: icaix1plp
    • M3: icw8s4plp
    Note: This scenario can also be useful if you want to change hardware but keep the network card on the replaced computer.
    Note: You do not need new license keys because the three computer IDs remain the same.

Replace the Network Card of a Failover Member

Before you begin: In the following scenario, let us assume you have a failover cluster with the following three cluster members, M1, M2 and M3:
  • M1: icwvc1plp
  • M2: icaix1plp
  • M3: icw8s4plp
  1. Stop failover member M1 and replace the network card of M1 with a new network card.
  2. Install a DS License Server from scratch on member M1.

    In case an administration port different from the default one (4084) has been set for the cluster, do specify this particular number when installing from scratch.

  3. Do not configure M1.

    In particular, do not set passwords and do not set failover mode. Any passwords, the failover mode and the other settings will be automatically transferred in the next steps.

  4. Obtain replacement failover license keys for the computer IDs M1, M2 and M3.
  5. From failover member M2, start the License Administration Tool.
  6. In the Server Configuration dialog box for your cluster, click the ... after member M1:



    The Modify Cluster Member dialog box appears.

  7. Select the Update computer id option.



    Then, click OK.

    The following warning appears:

    Warning: Enrolled licenses will be invalidated within 24 hours.
You should be ready after this operation to enroll a full set of licenses.
Do you want to proceed?

    Click Yes.

    Your cluster will be updated with a new computer id for member M1.

  8. Enroll new licenses generated for the cluster.

    New cluster licenses are required because one of the three computerIDs in the failover cluster has changed. For practical reasons, we strongly recommend that you obtain the new licenses before changing the computerID of a cluster member.

    Note: If two members are active, the failover cluster remains operational. When one computerID of the failover is changed, the cluster remains up but the old licenses are considered still valid for a maximum duration of 24 hours only. The new licenses containing the replacement computerID must be enrolled during this 24-hour period. Obtaining the new licenses before is critical.

    After enrolling the new licenses, your new cluster licenses are Active and users-licenses associations are kept the same as before:



    At any time during these steps, licensing clients were able to receive licenses.

Repair Corrupted Data of a Member

Before you begin: In the following scenario, let us assume you have a failover cluster with the following three cluster members, M1, M2 and M3:
  • M1: nuq32plp
  • M2: icaix1plp
  • M3: iclin3plp

Let us also assume that license data on cluster member M2 is corrupted by an operating system reinstallation, for example, but that M1 and M3 are both up and running.

  1. Stop failover cluster member M2.
  2. Install a DS License Server from scratch on member M2.

    In case an administration port different from the default one (4084) has been set for the cluster, do specify this particular number when installing from scratch.

  3. Do not configure M2.

    In particular, do not set passwords and do not set failover mode. Any passwords, the failover mode and the other settings will be automatically transferred in the next steps.

  4. From failover member M1, start the License Administration Tool.
  5. In the Server Configuration dialog box for your cluster, click the ... after member M2:



    The Modify Cluster Member dialog box appears.

  6. Select the Repair computer option.



    Click OK to repair the corrupted data.

    Note: You do not need new license keys because the three computer IDs remain the same.