Excel Services – Architecture
Excel服務——體系架構
Before I continue to drill down on the features of Excel Services, I would like to explain the architecture at a high level and touch on configuration possibilities.
在我繼續勾勒Excel服務的特性以前，我想從一個較高的層次解說Excel服務的體系架構。
Excel Services is built on the SharePoint products and technologies platform. There are three core components of Excel Services
Excel服務是建立在SharePoint產品和技術平臺之上，有三個核心組件。
Excel Calculation Service
Excel Web Access
Excel Web Service
Excel計算服務
Excel網絡存取
Excel網絡服務
Box Diagram
圖框
Here is what each of these components do.
這里解釋每一個組件的作用.
Excel Web Access – This is a web-part in SharePoint that performs the “rendering” (development team speak for “creating the HTML”) of Excel Workbooks on a web page. This is perhaps the most visible component for the end user. For those of you familiar with SharePoint, you can use it like any other web part in SharePoint to create a wide range of web pages.
Excel網絡存取——SharePoint平臺網絡功能的一部分，負責"編譯"(開發團隊說這是"生成HTML ")Excel工作簿成為一個網頁. 對于最終用戶來說這也許是最顯而易見的部分. 對于熟悉SharePoint的你,你可以用它像SharePoint其他網絡功能一樣來建立包括很多行的網頁.
Excel Web Services – This component provides the programmatic access that I talked about yesterday. It is a web service hosted in SharePoint. You can use methods in this web service to develop applications that incorporate calculations done by Excel Services and to automate the update of Excel spreadsheets.
Excel網絡服務——這個組件提供目錄的存取，如同我昨天說的. 這是在SharePoint上的網絡服務. 你可以使用這個方法來開發服務網絡應用服務,將Excel表格的計算自動更新.
Excel Calculation Service – This is the component that loads the spreadsheets, calculates them, refreshes external data, and maintains session state for interactivity. This is the heart of Excel Services.
Excel計算服務——這個組件裝載并計算表格，刷新外部日期，保持最新 的版本。這是Excel服務的心臟。
Additionally, there is also a proxy that is used internally to handle the communication between the components on the web front end and the application server in multiple-server configurations. It also handles the load balancing in case there are multiple application servers in your installation.
此外還有一種新特性，是可以配置多臺服務器以達到使應用服務和網絡負載平衡。這可以通過你的安裝來進行規劃實現。
These three components are divided in two major groups – those that live on a front-end server (which we refer to as a “web front end”), and those that live on a back-end application server. In the simplest of the configurations, all these components could be running on the same machine (we call this a “single box” installation). In a typical production environment with significant number of users, the components on the web front end and the application server would be on different machines. It is possible to scale (up or out) these components independently.
這三個組件分為兩大類,前臺服務器(我們稱為"網絡前臺")組件,后端應用服務器組件. 在簡單的配置中,這些組件可以運行在同機器(我們稱之為"單盒"安裝). 在有大量不同用戶的典型環境中,前臺后臺組件可以運行在不同的機器上。也就是說在將來這些組件有可能都是獨立的。.
Security
安全
Excel Services leverages the security infrastructure provided by SharePoint. Excel services uses SharePoint for authentication (who can log into the server) as well as authorization (who has access to which spreadsheet and the type of access; read, write, view only etc.). This provides a robust security environment for protecting your spreadsheets.
憑借SharePoint安全基礎設施Excel服務同樣安全. Excel使用SharePoint的認證服務, (登陸服務器)以及授權(獲取表格的類型和使用; 讀、寫、瀏覽等等). 這個環境為你的表格提供了有力的安全保障.
Performance and Scalability
性能和擴充
Excel Services are optimized for scenarios in which multiple users access the same spreadsheets. We have done a lot of work to optimize for this scenario – for example, caching at multiple levels so that collective performance for a group of users is improved by caching spreadsheets as well as external data queried by the spreadsheets. All this is transparent to the end user except for the good response time. (Anticipating a question, we only share cached results between users that have the same rights.)
Excel服務優化了多用戶使用同一表格工作. 為優化這種狀況我們已經做了大量工作,例如在多層次上的高速緩沖存貯使用戶組可以在不同的時間里集體編輯同張表格. 在最終用戶希望有很快的反映時間這個問題上所有的一切都是可見的. (預計到了這個問題,對于有相同權限的用戶之間我們僅僅共享緩存上的結果).
Excel Services can be scaled up by adding additional CPUs or memory to the server it runs on. It will take full advantage of multiple CPUs to handle multiple requests concurrently. It also supports 64bit CPUs. And it is possible to scale out the web front end and application server components independently, so you can adjust either based on server load and performance requirements. For example, if there is a bottleneck in rendering spreadsheets with Excel Web Access, then you can add more web front ends, and if there is a bottleneck is in calculations, then you can add more application servers to the farm. A lot will depend on the type, size of the workbooks and external data connections in the workbooks you are planning to use with Excel Services. For large deployments, some planning will need to go into the number of users as well as the anticipated workbook mix for the installation. The architecture is designed to meet the needs of a spectrum of deployments from a departmental to enterprise. The multi-tiered approach also allows for better security and isolation of services, for example in extranet scenarios.
Excel服務可相應增加中央處理器或內存以升級的服務器. 它將充分利用多個中央處理器同時處理多個請求. 它也支持64bit中央處理器. 并可以將運行的網絡應用服務器前臺后臺獨立分開,可以調整基于服務器負載的性能要求. 舉例來說,如果在Excel編譯上存在瓶頸, 你可以增加編譯網頁的資源,如果有一個瓶頸是計算,則可以增加應用服務器的資源. 針對不少取決于類型、規模的電子工作簿,你可以考慮使用Excel服務. 對于大規模的部署你要計劃需進入用戶數并預期的考慮如何分配安裝. Excel服務完全可以滿足一系列部署,從企業部門到多層次的安全，還可以更好地隔離服務,例如外聯網的情況.
Next time, more detail on publishing a spreadsheet to the server and viewing it in the browser.
下次將會發布更多關于發表電子表格到服務器上和在瀏覽器中閱讀表格的細節。
發布Thursday,November10,2005,9:26am 大衛Gainer
