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Cloudscape Database Applications
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Cloudscape Deployment OptionsThis section covers the possible deployment options for Cloudscape and how they differ. What Does Embedded Mean?When you deploy a Java application along with the Cloudscape engine and a copy of your database, Cloudscape is said to be embedded in the application. As you saw in Lesson 2, "Cloudscape Basics and the Sample Database", the application makes a call to the Cloudscape JDBC driver to start up the local Cloudscape software. The application does not need any special network connections to access the database software. When embedded in a single-user application, the Cloudscape software appears to be an integral part of the application and does not require any action or configuration on the user's part. Figure 5-1 When Cloudscape runs in an embedded environment, both the application and the Cloudscape software run within the same JVM. The database is stored in the local file system. An application starts up Cloudscape running in an embedded environment by loading the Cloudscape driver: Class.forName("COM.cloudscape.core.JDBCDriver").newInstance(); An application connects to Cloudscape running in an embedded environment by specifying the database connection URL as an argument to a call to the DriverManager: Connection conn = DriverManager.getConnection( After that, the application uses the methods of the java.sql API to execute SQL-J statements against the local Cloudscape database. NOTE: An ODBC-JDBC bridge will be available on our support Web site. This driver runs on top of the JDBC driver and allows existing ODBC applications to run against Cloudscape. Application Servers and Embedded CloudscapeApplications that provide services to many users can, like single-user applications, run with the Cloudscape engine embedded in them; like single-user disconnected applications, they run inside the same JVM as Cloudscape and make calls to Cloudscape through the local JDBC driver. Because Cloudscape runs embedded in the application, Cloudscape simplifies three-tier scenarios, eliminating network overhead between the application server and the DBMS. Figure 5-2 Cloudscape running in an application server Some third-party application servers may require a special driver on top of Cloudscape's local JDBC driver. Check our support Web site for information about the drivers that are available. Cloudscape's Server FrameworksCloudscape also offers JDBC server frameworks, which provide JDBC and in some cases HTTP services to remote client applications. When Cloudscape runs inside one of these frameworks, multiple users can access the same database or databases through the same server framework, which runs on a central server machine. The two frameworks provided by Cloudscape are:
Figure 5-3 When Cloudscape runs inside a server framework, client JDBC applications run in different JVMs (and most likely different computers) from the server. The database is stored in the file system local to the server. The system administrator starts up the server on the central machine. Client applications do not start up Cloudscape, but instead make calls to the server's client software. The server must already be running. Client applications start up the server's client software by loading the driver. The examples in this section are for use with the Cloudconnector framework: Class.forName( An application connects to Cloudscape running in an embedded environment by specifying the Cloudconnector client database connection URL as an argument to a call to the DriverManager: Connection conn = DriverManager.getConnection( After that, the application uses the methods of the java.sql API to execute SQL-J statements against the local Cloudscape database. After connecting, client JDBC applications running against a server and JDBC applications running against Cloudscape in an embedded environment work the same--through the methods of the JDBC interface. The only exception is that client applications do not need to shut down Cloudscape. For an example, see JDBC Servers. A Cloudscape Synchronization SystemCloudscape applications running against Cloudscape in an embedded environment can use the Cloudscape synchronization technology. The synchronization-enabled version of Cloudscape, called Cloudsync, has all of Cloudscape's features plus the synchronization technology. Synchronization allows occasionally connected databases to connect to a central Cloudscape database, known as a source, via the HTTP protocol and to share and synchronize data. When not connected, the remote application and Cloudscape software run exactly like an application running against Cloudscape in an embedded environment. The application starts the local JDBC driver, specifies the Cloudscape JDBC database connection URL, and interacts with the database through the methods of the JDBC interface. The synchronization technology handles updating data back and forth from the deployed databases and the server. When an embedded database uses synchronization, it is known as a target database. The source database runs inside a server product. Such a configuration supports the multiple HTTP connections from the target databases plus connections from JDBC client applications connected over the network. |
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![]() Cloudscape Version 3.6 For information about Cloudscape technical support, go to: www.cloudscape.com/support/.Copyright © 1998, 1999, 2000 Informix Software, Inc. All rights reserved. |