Chapter 7. High Availability in Alfresco

The high availability of any application is critical because of the global model of organizations. Also, with high throughput, multiple servers are required to support an application. This is where the clustering of nodes comes into the picture.

The typical requirements of high availability architectures are the following:

• Business continuity (up and running 24/7)

• Avoiding the single point of failure

• Hot backup

• Disaster recovery

In this chapter, we will discuss the ways of clustering in Alfresco and the backup restore process that supports the high availability of Alfresco.

By the end of this chapter, you will have learned about:

• Clustering Alfresco servers

• The backup process of Alfresco

• The restore process of Alfresco

Clustering Alfresco servers

Clustering refers to collections of multiple nodes combined together in a server as a single application to end users. With clustering, you can achieve scalability, server redundancy, and performance improvement of the application.

Let's consider a global financial organization that has multiple teams working for it across the globe. Alfresco is used as an enterprise content repository to store all the financial assets, like contracts. Now, these assets are very time-critical, and therefore the contracts should be accessible to all teams working on it at any time. There are thousands of users using the application, which also requires high server performance. High throughput is required for the server for users accessing assets in the system.

To satisfy these requirements, you will need to build a robust and highly available system by creating a clustered environment of Alfresco so the load on the server can be distributed. You also need a redundant and scalable...

The backup and restore process

For an application to be robust, a proper backup process for all data is very important. Here, we will cover details about what steps are required for backing up and restoring data in Alfresco.

Backups are required for the main critical components of Alfresco which hold the data, as listed below.

• Database: You can use the database dump method based on the type of database used for backup. There is a very good tool, Xtrabackup for MySQL, using which, backing up a large database is trivial. Refer to http://www.percona.com/software/percona-xtrabackup. As the repository size grows, the DB size will be large, so an efficient and incremental backup and restore strategy should be defined for the database.

• ContentStore (All Binary Files): Standard file system replication can be used to back up the content store. An important point to note here is that as your repository size grows, a full backup of the content store will become a time consuming process. So, always...

Summary

The Alfresco server can be clustered together to have a more robust, scalable, and highly available ECM server. Alfresco provides you with the flexibility to distribute the nodes and cluster them in multiple tiers based on your requirements. Repository and Share clustering is supported by Hazelcast. The Admin Console of Alfresco provides you with details about all the clustered nodes and also allows admin users to verify the clustering of nodes. Alfresco doesn't provide its own backup and restore process, but we can use industry-standard filesystem and database backup mechanisms to ensure a robust backup of your applications.

In the next chapter, we will talk about how Alfresco actually stores content. The content lifecycle will also be discussed in detail. This chapter will also cover in detail the important tables in the Alfresco database.