Chapter 20. Clustering and High Availability

Table of Contents

About Clustering
Microsoft Cluster Server (MSCS) on Windows
Mode 1 - Clustering at the Print Provider layer
Mode 2 - Clustering at all application layers
Clustering Tips
Veritas Cluster Server (VCS) on Windows
Mode 1 - Clustering at the Print Provider layer
Novell Cluster Services (NCS) on Novell OES Linux
Mode 1 - Clustering at the print provider layer
Mode 2 - Clustering at all application layers
Client/Workstation Configuration

About Clustering

PaperCut NG is designed to scale to 60,000+ users. To ensure reliability on networks of this size, network architects may adopt strategies including:

  • Load balancing - spreading tasks across multiple servers.

  • Clustering - building in redundancy by implementing a failover strategy.

PaperCut NG is a cluster compatible application. It supports clustering at all levels of the application, including

  • Clustering at the print spooler service layer by integrating with clustering services.

  • Failover based clustering at the application server layer using clustering services. (PaperCut NG's application server is web and web services based, and hence can support other failover methods such as heartbeat driven DNS).

  • At the database layer by utilizing cluster aware databases such as Microsoft SQL Server or Oracle.

Setting up PaperCut NG in a cluster environment is an advanced operation. This chapter assumes the reader has a high level of expertise in system and cluster configuration. The cluster environment should be operational before undertaking the PaperCut NG installation. Readers should also have a good understanding of PaperCut NG's Service Oriented Architecture - specifically its two main components, the Application Server and the Print Provider and how they work together (the section called “Print Monitoring Architecture”).

In a cluster environment, PaperCut NG can be set up in one of two possible configurations.

Mode 1 is the simplest configuration and is suitable for most organizations. It implements clustering in the “front line”, that is, the printer and print monitoring layer. The cluster print server is configured as a secondary print server reporting back to a primary PaperCut server hosted on another system outside the cluster.

Mode 2 implements clustering on all levels of the application for maximum fault tolerance - In addition to the print queues, the PaperCut Application Server is also hosted in the cluster. Mode 2 is somewhat more demanding to configure and should only be attempted by organizations with staff experienced with advanced cluster and database management.

Please refer to the subsequent sections for an explanation on how to set up Mode 1 or Mode 2 in your environment.