1. What is synctool

synctool is a tool that can help you administer your cluster of computers. Its primary function is keeping configuration files ‘in sync’, i.e.: as they ought to be. Its core business is copying configuration files to groups (or classes) of computers within a cluster and comparing such files with a normative copy that you keep in a repository. The repository, by the way, is not some database system, but an ‘overlay’ directory tree in a file system, that looks very much like the directories of the managed target systems. The only things missing from the repository are the files and directories that you do not want or need synctool to manage. In the repository, you can manage directories with conventional UNIX tools — cp, mv, mkdir — or any tool you like, and you can edit files with the editor of preference.

There are other tools in existence that do the same thing as synctool, and ironically, none of them are as easy to understand and use as synctool. Perhaps this is so, because other tools try to do the same thing, among many other things as well. synctool does not try to be an all encompassing system administation tool, and does not have its own little scripting language to define your system in. It does not strive to automate all aspects of the system administrator’s work. Rather, it focuses on its core business only and concentrates on doing that very well. This is very much in line with the traditional UNIX design philosophy — and with common sense. The powerful set of now common shell tools grew by adding commands that were designed to do only specific tasks very well and to be used easily in combination with other tools that specialize in other tasks.

Because of that design philosophy:

In addition, synctool simplifies things by working with the following concepts:

synctool manages configuration files, not processes, and not full system installations. However, synctool comes with handy tools to run commands across the cluster and do synchronized updates of software packages.

synctool does not hide UNIX from you. Making clever use of synctool makes it a very powerful tool.

synctool started in 2003 and has since been in use with great success, doing real work at big computing sites. Hopefully, it will be of some value to you as well.