Category: Cluster (Overview)#

The Cluster (Overview) category is the global overview category for cluster objects. It shows a summary of the entire cluster configuration at a glance: quorum status, assigned administration services, members, and cluster services. It is a single-value category and serves primarily as an entry point -- the actual data maintenance takes place in the respective detail categories.

Usage#

Typical use cases:

• Quick overview in daily operations: Open a cluster object and see at a glance how many nodes are assigned, whether a quorum is active, and which management service controls the cluster. Without having to switch between multiple categories, you get the complete picture.
• Dashboard and report basis: Since the overview category bundles all essential cluster information, it is suitable as a data source for reports that present the cluster status of all systems on one page.
• Entry point for navigation: From here, you navigate to the detail categories with a click. The displayed members and services are linked -- a click leads directly to the respective server or service object.
• Incident management: In an emergency, the overview immediately provides answers to the most important questions: How many nodes does the cluster have? Is a quorum configured? Which management service is responsible?

Fields#

Quorum#

Shows whether a quorum is configured for the cluster (Yes / No). The value is taken from the specific category Cluster. An active quorum means that the cluster only continues operating with the majority of nodes during a network partition -- a central protection mechanism against split-brain situations.

Administration service#

Lists the management services assigned to the cluster via the Cluster service assignment category. Typical examples: VMware vCenter, Microsoft Failover Cluster Manager, Pacemaker. The display is read-only -- changes are made in the service assignment category.

Cluster members#

Shows the servers and hosts registered as nodes in the cluster. Maintenance is done in the Cluster members category. Each entry is a link to the corresponding server object.

Number of cluster members#

The total number of assigned cluster members as a numeric value. Particularly useful for quick plausibility checks -- if a 3-node cluster suddenly shows only 2 members, action is needed.

Cluster service assignment#

Lists the services and applications assigned to the cluster. These assignments define which services run on the cluster (e.g. database service, web server service).

Description#

Free text with supplementary information about the cluster. Taken from the specific category Cluster.

Technical reference#

Fields (API reference)#

API examples#

Create entry#

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{
    "jsonrpc": "2.0",
    "method": "cmdb.category.save",
    "params": {
        "apikey": "your-api-key",
        "object": 569,
        "category": "C__CATG__CLUSTER_ROOT",
        "data": {
            "quorum": 1,
            "description": "Production HA cluster, 3 ESXi hosts, quorum via vCenter HA Admission Control"
        }
    },
    "id": 1
}

Read entries#

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{
    "jsonrpc": "2.0",
    "method": "cmdb.category.read",
    "params": {
        "apikey": "your-api-key",
        "object": 569,
        "category": "C__CATG__CLUSTER_ROOT"
    },
    "id": 2
}

Update entry#

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{
    "jsonrpc": "2.0",
    "method": "cmdb.category.save",
    "params": {
        "apikey": "your-api-key",
        "object": 569,
        "category": "C__CATG__CLUSTER_ROOT",
        "entry": 1,
        "data": {
            "quorum": 0,
            "description": "Migration to 2-node cluster completed. Quorum via shared witness disk."
        }
    },
    "id": 3
}