Upgrade a high availability pair

One of the requirements of Citrix ADC appliances in a high availability setup is to install the same Citrix ADC software release on both appliances of the setup. Therefore, when software on one appliance is upgraded, ensure that the software is upgraded on both the appliances.

You can follow the same procedure to upgrade a standalone appliance or each appliance in a high availability pair, although additional considerations apply to upgrading a high availability pair.

Before you start a Citrix ADC firmware upgrade on an HA pair, read the prerequisites mentioned in the Before you begin section. Also, you need to consider a few HA-specific points.

Points to note

  • First upgrade the secondary node, and then the primary node. Upgrading software on the secondary appliance before the primary appliance ensures that the upgrade process is completed without any issues.

  • If both the nodes in a high availability (HA) setup are running different Citrix ADC software releases, the following functionalities are disabled:
    • HA config synchronization
    • HA command propagation
    • HA synchronization of states services information
    • Connection mirroring (connection failover) of sessions
    • HA synchronization of persistence sessions information
  • The above mentioned functionalities are disabled, if both the nodes in a high availability (HA) setup are running different builds of the same release but both the builds have different internal HA versions. The above mentioned functionalities works fine if both the nodes in a high availability (HA) setup are running different builds of the same release but both the builds have the same internal HA versions.

    Refer to the Points to note section of the release notes to check if the internal HA version has changed in Citrix ADC build.

  • Synchronization of the files in the All mode of the Sync HA files command works successfully if the two nodes in an HA configuration are running different Citrix ADC software releases, or the two nodes are running different builds of the same release. For more information, see Synchronising Configuration Files in High Availability Setup.

Figure. Upgrade a high availability pair

localized image

You can upgrade using the Citrix ADC CLI or GUI.

Upgrade a high availability pair by using the CLI

The upgrade process includes the following steps:

  1. Upgrade software on the secondary appliance
  2. Upgrade software on the primary appliance
  3. Synchronize secondary appliance

Upgrade software on the secondary appliance

The following illustration depicts the procedure to upgrade software on the secondary appliance:

localized image

  1. Log on to the secondary NetScaler appliance using an SSH utility, such as PuTTY and specifying the NetScaler IP (NSIP). Use the nsroot credentials to log on to the appliance.

  2. From the command line interface of the appliance, type the following command to save the existing configuration: save config

  3. Switch to the shell prompt.

    login as: username
    Using keyboard-interactive authentication.
    Password:
    Last login: Wed Jun 24 14:59:16 2015 from 10.252.252.65
    Done
    > shell
    Copyright (c) 1992-20
    
    
  4. Run the following command to change to the default installation directory: # cd /var/nsinstall

  5. Run the following command to create a temporary subdirectory of the nsinstall directory: # mkdir x_xnsinstall

    Note: The text x_x is used to name the NetScaler version for future configurations. For example, the directory for the installation files of NetScaler 9.3 us called 9_3nsinstall. Do not use a period (.) in the folder name, it can cause failed upgrades.

  6. Change to the x_xnsinstall directory.

  7. Download the required installation package and documentation bundle, such as “ns-x.0-xx.x-doc.tgz,” to the temporary directory created in Step 4.

    Note:

    Some builds do not have a documentation bundle as it does not have to be installed.

    Click the Documentation tab from the GUI to access the documentation.

  8. Before you run the install script, the files must be extracted and placed on the appliance. Use the following command to uncompress the bundle downloaded from Citrix website: tar -zxvf ns-x.0-xx.x-doc.tgz. The following is a quick explanation of the parameters used.

    x: Extract files

    v: Print the file names as they are extracted one by one

    z: The file is a “gzipped” file

    f: Use the following tar archive for the operation

  9. Run the following command to install the downloaded software: # ./installns

    Note: If the appliance does not have sufficient disk space to install the new kernel files, the installation process performs an automatic cleanup of the flash drive.

  10. After the installation process is complete, the process prompts to restart the appliance. Press y to restart the appliance.

  11. Log on to the appliance Command Line Interface using the nsroot credentials.

  12. Run the following command from to display the state of the NetScaler appliance: show ha node The output of the preceding command should indicate that the appliance is a secondary node and synchronization is disabled.

  13. Run the following command to perform a force failover and takeover as primary appliance: force failover

Here’s a sample configuration in the new primary node.

login: nsroot
Password: nsroot
Last login: Monday Apr  17 08:37:26 2017 from 10.102.29.9
Done
show ha node
        2 nodes:
1)      Node ID:      0
        IP:        10.0.4.2
        Node State: UP
        Master State: Primary
        ...
        Sync State: AUTO DISABLED
        Propagation: AUTO DISABLED
        ...
Done

Upgrade software on the primary appliance

The following illustration depicts the procedure to upgrade software on the primary appliance:

localized image

Note: After completing the “Upgrade software on the secondary appliance” procedure, the original primary appliance is now a secondary appliance.

  1. Log on to the secondary NetScaler appliance using an SSH utility, such as PuTTY. Use the nsroot credentials to log on to the appliance. Follow the same steps as mentioned in the above section to complete the installation process. We have to follow the same steps as mentioned in step 2 to step 9 in the previous section(Upgrade software of the secondary appliance)

  2. After the installation process is complete, the process prompts to restart the appliance. Press y to restart the appliance.

  3. Log on to the appliance Command Line Interface using the nsroot credentials.

  4. Run the following command to display the state of the NetScaler appliance: show ha node. The output of the preceding command should indicate that the appliance is a primary node and the status of the node state is marked as UP.

  5. Run the following command to perform a force failover to ensure that the appliance is a primary appliance: force failover

  6. Verify that the appliance is a primary appliance.

    Here’s an example configuration of the new primary node and the new secondary node.

    show ha node
        Node ID:      0
        IP:   10.0.4.11
        Node State: UP
        Master State: Primary
        ...
        ...
        INC State: DISABLED
        Sync State: ENABLED
        Propagation: ENABLED
        Enabled Interfaces : 1/1
        Disabled Interfaces : None
        HA MON ON Interfaces : 1/1
        ...
        ...
        Local node information
        Critical Interfaces: 1/1
    Done
    
    Show ha node
        Node ID:      0
        IP:   10.0.4.2
        Node State: UP
        Master State: Secondary
        ..
        ..
        INC State: DISABLED
        Sync State: SUCCESS
        Propagation: ENABLED
        Enabled Interfaces : 1/1
        Disabled Interfaces : None
        HA MON ON Interfaces : 1/1
        . .
        . .
        Local node information:
        Critical Interfaces: 1/1
    Done
    

Upgrade a high availability pair by using the GUI

Follow these steps to upgrade a Citrix ADC pair in a high availability setup, by using the ADC GUI. Consider an example of a high availability setup of Citrix ADC appliances CITRIX-ADC-A (primary) and CITRIX-ADC-B (secondary).

  1. Upgrade the secondary node. Log on to the secondary node GUI using administrator credentials, and perform the upgrade as described in Upgrade a Citrix ADC standalone appliance by using the GUI.

  2. Force failover. Perform a force failover on the secondary node using GUI as described in Forcing a node to fail over.

    After failover operation, the secondary node takes over as primary and the primary node becomes the new secondary node. After the failover operation in the example HA setup:

    • CITRIX-ADC-B becomes the new primary
    • CITRIX-ADC-A becomes the new secondary
  3. Upgrade the original primary node (new secondary node). Log on to the new secondary node GUI (CITRIX-ADC-A) and perform the upgrade as described in Upgrade a Citrix ADC standalone appliance by using the GUI.

  4. Force failover. Perform a force failover on the new secondary node (CITRIX-ADC-A) using GUI as described in Forcing a node to fail over.

    After this second failover operation, the state of both the nodes return to the same state as before starting the HA upgrade operation. After the failover operation in the example HA setup:

    • CITRIX-ADC-A becomes primary
    • CITRIX-ADC-B becomes secondary
  5. Verify the upgrade process. Log on to the GUI of both the nodes. Navigate to System > High Availability, on the details page, verify the HA state of both the nodes. Also, verify the upgraded release details displayed on the top pane of the GUI.