===== Multi instance configuration =====

  * A Redpeaks instance can be configured to work following 3 types of roles:
    * **Standalone Server**
    * **Primary Server**
    * **Agent**

  * Communication between Server and agents is **Unidirectionnal**: Only agents will initiate connection to the Server.
  * The Server doesn't require any inbound connection the agent's network.
  * The server can therefore be publicly accessible while the agents can be in protected area: **No need for SSL tunnel, VPN or complex network settings** to deploy a mutli-instance implementation and centrally manage the monitoring of multiple isolated environments.
  * This architecture can also be used to add more **robustness**, by having several monitoring agents and be **resilient** in case one goes down.

==== Role settings ====

  * Go to Settings->Admin configuration->Multi-instance.
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  * In the Multi-instance tab, you can configure:
    * **Primary server mode:** If active, the instance will manage monitoring configuration
    * **Agent:** If active, the instance will execute monitoring tasks (connect to systems, detect problems, generate metrics and alerts)
    * **Agent name:** A meaningful name to identify the agent in the primary sever (something better than IP)
    * **Primary server URL:** The primary server to bind to.

==== Registered agent settings ====

  * The registered agent tab will show all currently **ACCEPTED** and **PENDING** agents:
  * You can visualize information about each agent, Name, Status, CPU, Memory, Disk, Version, Drivers.
  * Two tables will display the agents details, the first will show ACCEPTED agents, the second the PENDING ones.
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==== Agent life cycle ====

  * When an agent registers for the first time in Redpeaks, it has a **PENDING** state. It will not execute any task.
  * An administrator will then **ACCEPT** the agent via the dedicated button
  * Few seconds later, the agent will appear in the list of accepted agents
  * When an agent is **ON** with a status **WORKING**, it is ready to execute monitoring tasks.
  * Monitoring workload will be evenly distributed across agents, according to their associations (see agents groups).
  * You can temporarily **deactivate** an agent by selecting it and using ACTION menu to press **Deactivate**. No more tasks will be executed.
  * You can **delete** an accepted agent. It will go back in the list of pending agents, until switched off.
  * If an accepted agent stops to poll the primary server, it will be detected after few minutes. Its state will switch to **OFFLINE** and its current workload will be rescheduled on other available agents.

**NOTE:** When several agents share the same workload, it is recommended to use similar specs for their servers.

==== Agents groups ====

  * The Server/Agent architecture has primarily be designed to centrally monitor systems from several isolated environments
  * That means that one agent might only have access to a subset of systems, and must only execute tasks related to them.
  * In the Agents groups tab, you can configure which group of systems will be monitored by which agent(s).
  * Simply select an agent and press the ''Assign'' button to load the list of groups. You can then mass assign several groups to an agent in one click.
  * You can also use the ''plus'' button to assign just one group.
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  * Agent to groups associations are displayed in the table at the bottom
  * You can delete single associations from the table or use assign for mass delete.

**NOTE:** In standalone mode, it is not necessary to assign groups to the local agent. But if you do so, unassigned groups won't be monitored.\\
**WARNING:** If a group is not assigned to any agent, all its systems won't be monitored and a warning popup will be displayed

===== Standalone server role =====

  * This is the **default mode**, no specific configuration is required.
  * Primary server and agent roles are both enabled. In this mode, Redpeaks is an agent and a primary server at the same time.
  * The server will manage the configuration, user interface and execute monitoring tasks.
  * Every Redpeaks instance with an enabled agent has a **local agent** used to execute monitoring tasks.
  * The agent will appear automatically in the list of accepted agents and cannot be deleted.

**NOTE:** In standalone mode, it is not necessary to assign groups to the local agent. But if you do so, unassigned groups won't be monitored.

===== Primary server role =====

  * In this mode, Redpeaks will manage the configuration of the monitoring and distribute tasks to one or several remote agents.
  * It will be used as monitoring portal for the users and also hold the database, and connect to the plugins.
  * **Primary server role** must be active in the Multi-instance tab
  * Full primary server URL, including scheme and port number must be registered in the **Primary server URL** field of each agent
  * Each agent bound to the server must be accepted once by the admin
  * Associations between groups and agents must be done via the Agents groups tab.
  * One group can be managed by several agents, in that case, group workload will be distributed across each compatible agent.
  * Some system settings from primary server will be propagated automatically to each agent:
    * ''Number of parallel tasks''
    * ''Monitoring process timeout''
    * ''Log level and duration''
  * Most others like ''Monitoring process memory'' will still be local settings
  * If the **Agent role** is enabled, the local agent will be used as any remote agents.

**NOTE:** You can visualize agent activities in the **Monitor statistics** menu (Must activate monitors results retention in System tab)

===== Agent role =====

  * In Multi-instance tab, activate **Agent** mode and deactivate **Primary server role**
  * Define the agent name to use
  * Set the primary server URL
  * Save the settings. The agent will connect to the primary server and will be handled from there.
  * Some local settings will still remain available, such as ''System->monitoring processes memory'' or ''log retention''
  * **Connecting to primary server in HTTPS**:
    * Server must use an certificate generated for its actual IP (will not work will the default certificate)
    * Download server certificate using your browser and add it in the Redpeaks keystore of the agent (see [[https|HTTPS config]] for more details)

**NOTE:**
  * If the instance was previously used as a server, its configuration will be hidden until switched back to its server role.
  * The Agent doesn't require any licence