Red Hat Software

Red Hat Application Server - An open source middleware platform for Java-based applications

Red Hat Global File System - Leading Linux Cluster File System

Red Hat Cluster Suite - High availability & Load Balancing

Red Hat Developer Suite - Simplifies migration of applications and developer skills


Red Hat Cluster Suite

Red Hat Cluster Suite provides two distinct types of clustering:

Cluster Manager - Provides high availability for applications using failover technology

IP Load Balancing - Provides the ability to load balance incoming IP network requests across a farm of servers.

Red Hat Cluster Suite was designed specifically for Red Hat Enterprise Linux systems. Companies requiring applications to be highly available, or wishing to improve the performance and availability of their network infrastructure, should consider using a Red Hat Cluster Suite configuration.

Red Hat Cluster Suite is supported for use with Red Hat Enterprise Linux AS and Red Hat Enterprise Linux ES on Intel x86-compatible systems, and it is delivered on an annual subscription basis with one year of support services. The level of support is inherited from the underlying Red Hat Enterprise Linux subscription. The product is available exclusively as a download.

Cluster Manager

The Cluster Manager feature of Red Hat Cluster Suite provides an application failover infrastructure that can be used by a wide range of applications, including:

  • Most custom and mainstream commercial applications
  • File and print serving
  • Databases and database applications
  • Messaging applications
  • Internet and open source application

With Cluster Manager, these applications can be deployed in high availability configurations so that they are always operationalbringing "scale-out" capabilities to enterprise Linux deployments.

For high-volume open source applications, such as NFS, Samba, and Apache, Cluster Manager provides a complete ready-to-use failover solution. For most other applications, customers can create custom failover scripts using provided templates. Red Hat Professional Services can provide custom Cluster Manager deployment services where required.

Features

  • Support for up to eight nodes: Allows high availability to be provided for multiple applications simultaneously.
  • NFS/ IFS Failover: Supports highly available file serving in Unix and Windows environments
  • Fully shared storage subsystem: All cluster members have access to the same storage.
  • Comprehensive Data Integrity guarantees: Uses the latest I/O barrier technology, such as programmable power switches and watchdog timers.
  • SCSI and Fibre Channel support: Cluster Manager configurations can be deployed using latest SCSI and Fibre Channel technology. Multi-terabyte configurations can readily be made highly available.
  • Service failover: Cluster Manager not only ensures hardware shutdowns or failures are detected and recovered from automatically, but also will monitor your applications to ensure they are running correctly, and will restart them automatically if they fail.

IP Load Balancing

IP Load Balancing (often known by its project name, Piranha) provides the ability to load-balance incoming IP network requests across a farm of servers. IP Load Balancing is based on open source Linux Virtual Server (LVS) technology, with significant Red Hat enhancements.

An IP Load Balancing (IPLB) cluster appears as one server, but, in reality, a user from the Web is accessing a group of servers behind a pair of redundant IPLB routers. An IPLB cluster consists of at least two layers. The first layer is composed of a pair of similarly configured Red Hat Enterprise Linux AS or ES systems with Red Hat Cluster Suite installed. One of these nodes acts as the active IPLB router (the other acts as a backup), directing requests from the Internet to the second layer--a pool of servers called real servers. The real servers provide the critical services to the end-user while the LVS router balances the load to these servers.

The active router serves two roles in the cluster:

  • Balancing the load on the real servers
  • Checking integrity of the services on each of the real servers.

The figure shows a simple IPLB cluster consisting of two layers. On the first layer are two IPLB routers. The active system directs traffic from the Internet to a variable number of real servers on the second layer, which in turn provide the necessary services.

The simple, two-layered configuration used in the figure is best for clusters serving data that does not change very frequently--such as static Web pages--because the individual real servers do not automatically synchronize data between each node. If high-availability shared data access and update is required, a third layer is added to the topology. Cluster Manager is ideal for this purpose, so both clustering types can be used together to create a high availability three-tier solution with full transactional capabilities.