Distributed monitoring
Resource Manager supports distributed monitoring through the use of collectors, hubs, and resource pools; each of which is detailed in the sections below.
At installation, Resource Manager is configured with one hub and one collector (each named localhost). The initial hub and collector cannot be removed.
About collectors
A collector is a logical set of collection services that share a common group of monitored devices. Collection services are distributed across all of the the hosts in the collector's resource pool. When you add a device to Resource Manager, you choose the collector to which it is assigned, which will normally be the collector that runs on the same network as (or closest network to) the device. You can move a device from one to collector to another if necessary.
Collector services retrieve and accept data from your IT infrastructure for
- Monitoring
- Modeling
- Event generation
Collector data storage
Collector services initially queue collected performance metrics to a Redis key-value store on the collector, and then send the data to a single OpenTSDB (time series database) instance that runs on HBase for persistent storage.
Managing collectors
In Resource Manager, collector services appear under their collector name on the ADVANCED > Control Center page and can be started, stopped, and restarted from there. You can click on the name of a service to display its details, configuration files, and logs.
About hubs
A hub represents one or more instances of the zenhub service, through which all collector services communicate with the object and event databases. Resource Manager supports multiple hubs, although most Resource Manager deployments require only one hub. All collectors must belong to exactly one hub; however, many collectors can be associated with a single hub. All hubs (and indirectly all collectors) refer to the same object and event databases. Typically, only very large systems benefit from multiple hubs. We recommend that you contact Zenoss Support or Professional Services before adding a new hub.
About resource pools
A resource pool is a group of hosts running the Control Center software that reside on the same local area network (LAN). When you add a host to Control Center you specify the resource pool to which it will belong. This allows for better collector distribution and efficiency by minimizing the network latency between collectors and the devices they monitor.
Initially, a single resource pool named default is defined. You can create additional resource pools by identifying them with a unique pool name. You can then add hosts and assign them to the desired pool. Once the resource pool is configured, you can add a collector that runs on that resource pool.