Linux Pacemaker Cluster discovery

  • Release version: Washingtondc
  • Updated February 1, 2024
  • 2 minutes to read

    • The ServiceNow Discovery application uses the Linux Pacemaker Cluster discovery pattern to find high-availability cluster data and populate the CMDB with the discovered information. Discovering some of these resources requires updating the Discovery and Service Mapping Patterns application from the ServiceNow Store.

    This pattern is an extension section of the Linux Server pattern. Discovery uses the pattern to run horizontal discovery.

    You can use this pattern on the ServiceNow AI Platform® using the Madrid release or later.

    Request apps on the Store

    Visit the ServiceNow Store website to view all the available apps and for information about submitting requests to the store. For cumulative release notes information for all released apps, see the ServiceNow Store version history release notes.

    Prerequisites

    • Configure SSH credentials for the Linux server.
    • Provide a user with permissions to read the following files:
      • /etc/hosts
      • /etc/corosync/corosync.conf
      • /var/lib/heartbeat/crm/cib.xml, or /var/lib/pacemaker/cib/cib.xml from Linux SP3
    • Provide a user with permissions to run the following commands:

      ps -ef | grep corosync | grep -v grep

      ps -ef | grep pacemaker | grep -v grep

      ifconfig | grep 'inet addr:' |awk '{print $1, $2 }'

      hostname -s

      hostname -f

    Data collected by Discovery during horizontal discovery

    The discovered data includes the following tables and fields.
    Table and field Description
    Main CI - UNIX Cluster [cmdb_ci_unix_cluster]
    name Cluster name.
    cluster_id Cluster ID. Contains the nodes ID.
    cluster_type Cluster type.
    cluster_status Cluster status: Online/offline.
    cluster_version Cluster version.
    UNIX Cluster Resource [cmdb_ci_unix_cluster_resource]
    name Resource name.
    resource_type Resource type.
    resource_status Resource status. For example, Started.
    ip_address IP address of the machine where the resource is running.
    fqdn FQDN of the machine where the resource is running.
    Cluster Virtual IP [cmdb_ci_cluster_vip]
    name Cluster VIP name.
    ip_address IP address of the VIP.
    Cluster Resource Group [cmdb_ci_cluster_resource_group]
    name Resource group name.
    node Resource group node.
    resource_group_status Resource group status.
    server Resource group server.
    fqdn FQDN of the machine where the resource group is running.
    UNIX Cluster Node [cmdb_ci_unix_cluster_node]
    name Node name and node ID.
    node_status Node status.
    node_state Node state.
    fqdn FQDN of the machine where the node is running.
    The Dependency Views map shows discovered load balancer CIs and the relationships between them.
    CIs and connections on a Dependency Views map

    CI relationships

    These relationships are created to support Linux Pacemaker Cluster discovery:
    CI Relationship CI
    cmdb_ci_unix_cluster Hosts::Hosted on cmdb_ci_linux_server
    cmdb_ci_unix_cluster_node Hosted on::Hosts cmdb_ci_linux_server
    Cluster of::Cluster cmdb_ci_unix_cluster
    cmdb_ci_cluster_vip Uses::Used by cmdb_ci_unix_cluster_node
    Virtualized by::Virtualized cmdb_ci_unix_cluster
    cmdb_ci_unix_cluster_resource Defines resources for::Gets resources from cmdb_ci_unix_cluster
    Defines resources for::Gets resources from cmdb_ci_unix_cluster_node
    cmdb_ci_cluster_resource_group Contains::Contained by cmdb_ci_unix_cluster
    Contains::Contained by cmdb_ci_unix_cluster_node
    Contains::Contained by cmdb_ci_unix_cluster_resource