Active Directory (AD) is a directory service developed by Microsoft for Windows domain networks. It is included in most Windows Server operating systems as a set of processes and services. Initially, Active Directory was used only for centralized domain management. However, Active Directory eventually became an umbrella title for a broad range of directory-based identity-related services.
Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer network of nodes.
HCL Notes and HCL Domino are the client and server, respectively, of a collaborative client-server software platform formerly sold by IBM, now by HCL Technologies.
Coda is a distributed file system developed as a research project at Carnegie Mellon University since 1987 under the direction of Mahadev Satyanarayanan. It descended directly from an older version of Andrew File System (AFS-2) and offers many similar features. The InterMezzo file system was inspired by Coda.
A Web cache is a system for optimizing the World Wide Web. It is implemented both client-side and server-side. The caching of multimedias and other files can result in less overall delay when browsing the Web.
A content delivery network, or content distribution network (CDN), is a geographically distributed network of proxy servers and their data centers. The goal is to provide high availability and performance by distributing the service spatially relative to end users. CDNs came into existence in the late 1990s as a means for alleviating the performance bottlenecks of the Internet as the Internet was starting to become a mission-critical medium for people and enterprises. Since then, CDNs have grown to serve a large portion of the Internet content today, including web objects, downloadable objects, applications, live streaming media, on-demand streaming media, and social media sites.
NIS+ is a directory service developed by Sun Microsystems to replace its older 'NIS'. It is designed to eliminate the need for duplication across many computers of configuration data such as user accounts, host names and addresses, printer information and NFS disk mounts on individual systems, instead using a central repository on a master server, simplifying system administration. NIS+ client software has been ported to other Unix and Unix-like platforms.
A web accelerator is a proxy server that reduces website access time. They can be a self-contained hardware appliance or installable software.
A collaborative real-time editor is a type of collaborative software or web application which enables real-time collaborative editing, simultaneous editing, or live editing of the same digital document, computer file or cloud-stored data – such as an online spreadsheet, word processing document, database or presentation – at the same time by different users on different computers or mobile devices, with automatic and nearly instantaneous merging of their edits.
Push technology or server push is a style of Internet-based communication where the request for a given transaction is initiated by the publisher or central server. It is contrasted with pull/get, where the request for the transmission of information is initiated by the receiver or client.
Multi-master replication is a method of database replication which allows data to be stored by a group of computers, and updated by any member of the group. All members are responsive to client data queries. The multi-master replication system is responsible for propagating the data modifications made by each member to the rest of the group and resolving any conflicts that might arise between concurrent changes made by different members.
Gluster Inc. was a software company that provided an open source platform for scale-out public and private cloud storage. The company was privately funded and headquartered in Sunnyvale, California, with an engineering center in Bangalore, India. Gluster was funded by Nexus Venture Partners and Index Ventures. Gluster was acquired by Red Hat on October 7, 2011.
Microsoft Sync Framework is a data synchronization platform from Microsoft that can be used to synchronize data across multiple data stores. Sync Framework includes a transport-agnostic architecture, into which data store-specific synchronization providers, modelled on the ADO.NET data provider API, can be plugged in. Sync Framework can be used for offline access to data, by working against a cached set of data and submitting the changes to a master database in a batch, as well as to synchronize changes to a data source across all consumers and peer-to-peer synchronization of multiple data sources. Sync Framework features built-in capabilities for conflict detection – whether data to be changed has already been updated – and can flag them for manual inspection or use defined policies to try to resolve the conflict. Sync Services includes an embedded SQL Server Compact database to store metadata about the synchronization relationships as well as about each sync attempt. The Sync Framework API is surfaced both in managed code, for use with .NET Framework applications, as well as unmanaged code, for use with COM applications. It was scheduled to ship with Visual Studio 2008 in late November 2007.
SharePoint is a web-based collaborative platform that integrates natively with Microsoft Office. Launched in 2001, SharePoint is primarily sold as a document management and storage system, but the product is highly configurable and its usage varies substantially among organizations.
Open Cobalt is a free and open-source software platform for constructing, accessing, and sharing virtual worlds both on local area networks or across the Internet, with no need for centralized servers.
XtreemFS is an object-based, distributed file system for wide area networks. XtreemFS' outstanding feature is full and real fault tolerance, while maintaining POSIX file system semantics. Fault-tolerance is achieved by using Paxos-based lease negotiation algorithms and is used to replicate files and metadata. SSL and X.509 certificates support make XtreemFS usable over public networks.
A data grid is an architecture or set of services that gives individuals or groups of users the ability to access, modify and transfer extremely large amounts of geographically distributed data for research purposes. Data grids make this possible through a host of middleware applications and services that pull together data and resources from multiple administrative domains and then present it to users upon request. The data in a data grid can be located at a single site or multiple sites where each site can be its own administrative domain governed by a set of security restrictions as to who may access the data. Likewise, multiple replicas of the data may be distributed throughout the grid outside their original administrative domain and the security restrictions placed on the original data for who may access it must be equally applied to the replicas. Specifically developed data grid middleware is what handles the integration between users and the data they request by controlling access while making it available as efficiently as possible. The adjacent diagram depicts a high level view of a data grid.
A distributed file system for cloud is a file system that allows many clients to have access to data and supports operations on that data. Each data file may be partitioned into several parts called chunks. Each chunk may be stored on different remote machines, facilitating the parallel execution of applications. Typically, data is stored in files in a hierarchical tree, where the nodes represent directories. There are several ways to share files in a distributed architecture: each solution must be suitable for a certain type of application, depending on how complex the application is. Meanwhile, the security of the system must be ensured. Confidentiality, availability and integrity are the main keys for a secure system.
Elliptics is a distributed key–value data storage with open source code. By default it is a classic distributed hash table (DHT) with multiple replicas put in different groups. Elliptics was created to meet requirements of multi-datacenter and physically distributed storage locations when storing huge amount of medium and large files.
Mirror sites or mirrors are replicas of other websites or any network node. The concept of mirroring applies to network services accessible through any protocol, such as HTTP or FTP. Such sites have different URLs than the original site, but host identical or near-identical content. Mirror sites are often located in a different geographic region than the original, or upstream site. The purpose of mirrors is to reduce network traffic, improve access speed, ensure availability of the original site for technical or political reasons, or provide a real-time backup of the original site. Mirror sites are particularly important in developing countries, where internet access may be slower or less reliable. The maintainers of some mirrors choose not to replicate the entire contents of the upstream server they are mirroring because of technical constraints, or selecting only a subset relevant to their purpose, such as software written in a particular programming language, runnable on a single computer platform, or written by one author. These sites are called partial mirrors or secondary mirrors.
