| Red Hat Docs > Manuals > Red Hat High Availability Server Manuals > |
|
| Red Hat Linux 6.2: The Official Red Hat High Availability Server Installation Guide | ||
|---|---|---|
| Prev | Chapter 8. Linux Virtual Server (LVS) | Next |
The components of an LVS cluster are described below.
This is the controlling process that starts the other daemons as needed. It is started on the LVS routers by the /etc/rc.d/init.d/pulse script, normally at boot time . Through pulse, which implements a simple heartbeat, the inactive LVS router determines the health of the active router and whether to initiate failover.
The lvs daemon runs on the LVS routers. It reads the configuration file and calls ipvsadm to build and maintain the IPVS routing table.
The nanny monitoring daemon runs on the active LVS router. Through this daemon, the active router determines the health of each real server and monitors its workload. A separate process runs for each service defined on each real server.
This is the LVS cluster configuration file. Directly or indirectly, all daemons get their configuration information from this file.
The Web-based tool for monitoring, configuring, and administering an LVS cluster. Normally this is the tool you will use to maintain /etc/lvs.cf, restart the running daemons, and monitor an LVS cluster.
This tool updates the IPVS routing table in the kernel. The lvs daemon sets up and administers an LVS cluster by calling ipvsadm to add, change or delete entries in the IPVS routing table.
This program sends out ARP broadcasts when the virtual server address changes from one node to another.
This diagram shows the how the various components work together in an LVS cluster configuration:
