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HomeMy WebLinkAboutCLE200900096 Review Comments Zoning Clearance 2009-06-25Overview of Laserf iche 8 Architecture White Paper December 2008 The information contained in this document represents the current view of Compulink Management Center, Inc on the issues discussed as of the date of publication. Because Compulink must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Compulink, and Compulink cannot guarantee the accuracy of any information presented after the date of publication. This chapter is for informational purposes only. COMPULINK MAKES NO WARRANTIES, EXPRESS OR IMPLIED, AS TO THE INFORMATION IN THIS DOCUMENT. Table of Contents Server, Client and Repository Architecture ............................ ..............................3 Laserfiche Server ................................................................ ..............................3 ClientApplications ............................................................... ..............................3 LaserficheRepository ......................................................... ..............................4 Communications..................................................................... ..............................5 How the Components Work Together ..................................... ..............................5 2 The core of a Laserfiche installation is the Laserfiche Server. The Server hosts the collection of documents and folders you manage with Laserfiche (which are collectively called a repository), and distributes them to client applications when users request the documents and document information. The Server also maintains the metadata about the repository: security settings and calculations, the structure in which the documents will be displayed to the user, annotations on documents, and additional user - defined data that users can apply to documents and folders. This allows users to open and modify documents using Laserfiche client applications as though they were working on them locally, while still taking advantage of the performance and space enhancements available when files are distributed over more than one computer. This paper describes the architecture of the Laserfiche Server, and its implications on performance and usability. Server, Client and Repository Architecture A Laserfiche installation consists of several components, which can be distributed across different computers to enhance performance and take advantage of more than one hard disk for storage. Laserfiche Server The Laserfiche Server runs as a service on the computer on which it was installed, and should run continually (except when taken down for maintenance). The Server will always be available to users, as long as the Server service is running. The Laserfiche Server interacts with the files in your repository (see 'Repository," below) to deliver the necessary information to the users who request it. Whenever a calculation needs to be made, it is made by the Server — for instance, when a user attempts to open a document, the Server must calculate security for that document, and determine whether the user has the appropriate rights to open that entry. In other words, the Server contains the core logic that is the heart of a Laserfiche installation. The Full -Text Search Service runs as a separate service on the Server computer. It allows users to index documents that contain text, and make them available for fast, efficient full -text searching. Client Applications A client application is any application that communicates with the Laserfiche Server. Most Laserfiche products other than the Server are client applications: the Laserfiche Client, WebLink, Web Access, Quick Fields, Workflow, Import Agent, custom Toolkit scripts, and so on. Client applications communicate with the Laserfiche Server to send requests for documents and other 3 information, and then to receive the document files and metadata from the Server. Laserfiche Repository A Laserfiche repository is a collection of files and information managed using Laserfiche. The repository can contain scanned documents and electronic documents (such as Word files or PDFs), as well as the text used to make these documents searchable, annotations on the documents, and metadata about the documents. A repository also contains users, groups, and security information used to restrict access to the documents. When a user launches the Laserfiche Client and browses documents and folders, they are browsing through the repository. The repository looks and acts like a single, self- contained collection of documents and folders to the user, but it actually consists of several components, which may be distributed across several different computers. This allows administrators to distribute your files to enhance performance and to circumvent size limitations on a single hard disk. There are three basic components to your repository: the volume files, the database files, and the search index catalog. The repository also includes a repository location, on the Laserfiche server computer, that serves as the default location for volume files and the search catalog. Volumes: The volumes contain the actual files that make up the documents stored in your repository — the scanned image pages, text page, and electronic documents, as well as some supplemental information such as attachment annotation files, word location data, and thumbnails. Administrators can create more than one volume, and for performance reasons it is recommended that a repository use multiple smaller volumes rather than one large volume. (Logical volumes, which act as folders for volumes and which 'roll over' and create new volumes when a size limit is reached, allow you to automate this.) Volumes are stored in the Windows file system, at a user - specified location that you specify when you create the volume. They can be stored anywhere on the network, and multiple volumes can be distributed across more than one computer. Database Files: The database files contain all the information about the repository besides the actual files. This includes the repository folder structure, security information, annotation information, metadata, most repository options, searches other than full -text search, and so on. The database files are attached to and managed by a Database Management System (Microsoft SQL Server or Oracle), which can be installed on another computer in the network. 4 Search Index Catalog: The Full -Text Search Service creates and manages an index catalog that makes the text in the repository searchable. The index catalog is created in the repository directory, but can be moved to a new location on the Server computer (for example, if you wish to distribute them to a different hard disk on the same computer). Communications Laserfiche uses HTTP as its primary protocol for communication between the Server and client applications. HTTP is a firewall- friendly protocol with performance advantages for wide -area networks — because it is the same protocol used by browsers to access the Internet, most firewall software is designed to work with it readily. If a firewall is in place between the Server and a client application, the administrator will simply need to configure their firewall software to allow communication on specific ports. In addition, the Laserfiche implementation takes advantage of the WebDAV extensions to HTTP, which allow you to use Windows folder browsers to browse directly to folders in your repository in addition to working in the Client. How the Components Work Together When a user opens a document in the Client, the Client sends a request for the document to the Laserfiche Server using the HTTP communication protocol. The Server receives the request, and then communicates with the database to retrieve security information for the user and the entry, and performs the necessary security calculations to determine whether the user has the rights to open the document. If the user should not be able to open the document, the Server sends a 'Permission denied" message to the Client. If, however, the user does have access to the document, the Server communicates with the database again to find other necessary information about the document: what pages are contained within it, what annotations should be displayed on those pages, what metadata is associated with it, and so on. The Server also communicates with the volume files to retrieve the appropriate image pages, text pages, electronic document files, annotation attachments, and thumbnails to display with the page. If a user is searching, a similar process happens, in which the Laserfiche Server communicates with the Full -Text Search engine to determine which documents match the text search query, or with the database to determine which documents match other query types. The Server then sends all of the data — the pages, the document metadata, and so on — to the Client, which displays it to the user. The entire process occurs very quickly, usually in less than a second. From the perspective of the user, the document opens immediately after they click 5 on it; they aren't aware of the communication happening behind the scenes. However, distributing the parts of the repository in this way make it scalable (more documents can be stored in the repository than would fit on a single computer) and improve performance by distributing the various components. 0 Overview of Laserfiche 8 Architecture December 2008 Author: Constance Anderson Technical Editor: Justin Pava Compulink Management Center, Inc. Global Headquarters 3545 Long Beach Blvd. Long Beach, CA 90807 U.S.A Phone: +1.562.988.1688 www.laserfiche.com Laserfiche is a trademark of Compulink Management Center, Inc. Various product and service names references herein may be trademarks of Compulink Management Center, Inc. All other products and service names mentioned may be trademarks of their respective owners. Copyright © 2008 Compulink Management Center, Inc. All rights reserved