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Administering
Learn how to configure settings in HCL Launch elements and communication between the elements.
High availability and failover
You can configure clustered HCL Launch servers, blueprint design servers, and agents for high availability. You can also configure agents and agent relays for failover.
High availability overview
To configure clustered high availability for HCL Launch, you must use a load balancer. You can configure a cold standby server by using a load balancer or configuring the servers' DNS.
High-availability agent communication
Agents communicate with the server over JMS and HTTP or HTTPS. These modes of communication are handled differently in a high availability scenario.

Administering
Learn how to configure settings in HCL Launch elements and communication between the elements.
- High availability and failover
  You can configure clustered HCL Launch servers, blueprint design servers, and agents for high availability. You can also configure agents and agent relays for failover.
  - High availability overview
    To configure clustered high availability for HCL Launch, you must use a load balancer. You can configure a cold standby server by using a load balancer or configuring the servers' DNS.
    - High-availability server processes
      While high-availability servers complete the same processes as standalone servers, they run slightly differently and access files in run slightly different locations than individual servers do.
    - High-availability agent communication
      Agents communicate with the server over JMS and HTTP or HTTPS. These modes of communication are handled differently in a high availability scenario.
- Setting up high-availability clusters
  To configure a high-availability cluster, you store shared files on network storage. Then, you configure multiple servers, set each server to access the same files and database, and configure a load balancer to distribute the traffic between the servers.
- Configuring agents for failover
  To configure agents for failover, you specify two or more target servers for the agent to use. If one of the servers fails, the agent switches to another server from the list.
- Configuring agent relays for failover
  To configure agent relays for failover, you specify two or more target servers for the agent relay to use. If one of the servers fails, the agent relay switches to another server from the list.
- Server settings and configuration
  After you install HCL Launch, you can modify the server configuration and configure more options.
- Setting user preferences
  Each user can specify display options for the server, including the language for the server and how the server shows times and dates.
- Agents and agent relay configuration
  After you install an agent for HCL Launch, you can modify its configuration or create an agent relay to facilitate communication to remote relays.
- License management
  HCL Launch provides a 60-day license-free evaluation period. To use all product features after the evaluation period, you must have a license.
- Setting up the wizard for new users
  HCL Launch includes a wizard to help users become familiar with the procedures and steps in creating a deployment. Some configuration is required before the wizard can be used.
- Customizing the table views
  Customize a table view in the HCL Launch application by hiding or showing, and reordering of the table columns.
- Releasing VC LOB space
  After you upgrade to HCL Launch 7.0.5 and later, you can compress the amount of large object (LOB) storage space that HCL Launch uses in the vc_persistent_record database table.

High-availability agent communication

Agents communicate with the server over JMS and HTTP or HTTPS. These modes of communication are handled differently in a high availability scenario.

JMS communication

JMS communications is subscription-based. All agents subscribe to all topics and filter the list with their agent ID. For this reason, assigning unique IDs to agents is required.

For JMS-based communications, agents can be configured in two ways:

Approach 1: Agents are individually configured for failover. If an agent fails to connect to a server or agent relay, the agent connects to failover servers or agent relays. See Configuring agents for failover.
Approach 2: Agents connect to a single agent relay that is configured for failover. See Configuring agent relays for failover.

Approach 1 works best because it allows for you to configure stable failover configurations in ActiveMQ.

Note: Do not configure a load balancer to distribute requests for the agent communication JMS port. To ensure agent and agent relay availability, configure them for failover.

HTTP or HTTPS communication

A standard load balancer handles HTTP or HTTPS server-agent communications. Authentication is run on every request; any server can run validation for any request. You configure HTTP or HTTPS server-agent communication when you configure your cluster of servers. See Setting up clusters of servers.

In case of server failure, user-server authentication must be redone unless the ‘remember me’ cookie is used.