Unison is a file-synchronization tool for Unix and Windows. It allows two copies of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other. Unison can deal with updates to both replicas of a distributed directory structure. Updates that do not conflict are propagated automatically. Conflicting updates are detected and displayed. Unison can communicate through a direct socket link or through an rsh/ssh tunnel. It uses network bandwidth efficiently.
SystemImager automates the installation of Linux to masses of similar machines. Software distribution, configuration, and operating system updates are made easy, including updates from one Linux release to another. It can also be used for content distribution on Web servers. It is most useful in environments with large numbers of identical machines. Some typical environments include Internet server farms, high performance clusters, computer labs, and corporate desktop environments where all workstations have the same basic hardware configuration.
changedfiles is a framework for filesystem replication, security monitoring, and/or automatic file transformations--essentially any application where you'd poll files or directories and either do something to them or send them somewhere else (or both). The difference is that the kernel tells you when they change instead of you having to poll. It's an easy real time FTP push mirror to one or multiple sites. It's also a full fledged MySQL client, so you can do realtime database operations (for example, batch imports). It consists of two parts: a kernel module (works with Linux kernel version 2.4) which reports to a device whenever a file on the filesystem changes, and a daemon which runs in user space and can be configured to do almost any action when a change to a file matching the one of the patterns it looks for is reported. The kernel module is SMP safe and has been tested on Intel, PowerPC, and Alpha.
Radiant Data PeerFS is real-time peer-to-peer distributed replicating file system featuring global file and sectional locks. All read operations are performed locally, and only file changes are transmitted across the network. It supports databases such as MySQL, as well as images and documents. All nodes are active/active, allowing for load balancing. Clients can also be hot switched between nodes, eliminating downtime. It also supports AES encryption for use across the Internet.
radmind is a suite of Unix command-line tools and a server designed to remotely administer the file systems of multiple Unix machines. At its core, radmind operates as a tripwire. It is able to detect changes to any managed filesystem object, e.g. files, directories, links, etc. However, radmind goes further than just integrity checking: once a change is detected, radmind can optionally reverse the change. Each managed machine may have its own loadset composed of multiple, layered overloads. This allows, for example, the operating system to be described separately from applications. Loadsets are stored on a remote server. By updating a loadset on the server, changes can be pushed to managed machines.
Sequoia provides high availability and performance scalability for databases. It is is the continuation of the C-JDBC project. It provides transparent database clustering (partitioning, replication, etc.). It works with any Java application without code modification and with any database engine. It has been successfully tested with Tomcat, JBoss, JOnAS, WebSphere, MySQL, PostgreSQL, Apache Derby, HSQLDB, SAP DB, Oracle, DB2, Sybase, MS SQL Server, Firebird, and more.