Coherence provides replicated and distributed partitioned data management and caching services on top of a reliable, highly scalable peer-to-peer clustering protocol.
Coherence has no single points of failure; it automatically and transparently fails over and redistributes its clustered data management services when a server becomes inoperative or is disconnected from the network. When a new server is added, or when a failed server is restarted, it automatically joins the cluster and Coherence fails back services to it, transparently redistributing the cluster load.
Coherence includes network-level fault tolerance features and transparent soft re-start capability to enable servers to self-heal. A channels based publish-subscribe mechanism for Web-based clients to send and receive asynchronous messages over HTTP.
The HTTP Publish-Subscribe server can be used by Web clients to subscribe to channels a representation in Bayeux for destinations and publish messages to the channels. This is a Spring container for Java applications that use SCA semantics to expose services and invoke references. Server startup command. This properties file, which can be placed in any directory, registers the Server Logging Bridge handler in the application's logger tree. Example shows an example logging.
Example Example logging. The following example shows passing the logging. Server startup command:. When the appender receives an application log message, in the form of a org.
LoggingEvent object, the appender redirects the message to the WebLogic logging service destinations such as stdout, server log, domain log, and so on, as appropriate. The following information contained in the LoggingEvent determines how the log message is redirected:. If no logger name exists in the LoggingEvent , the message is published to the root logger. To use the Server Logging Bridge appender, create a log4j.
The log4j. For detailed information about configuring Log4j logging, see the following Logging Services documentation published by logging. Example shows an example log4j. Example Example log4j. By default, log messages originating from loggers with the com. However, you can propagate messages to the application's root logger by enabling the LogMBean. If you are using Log4j for application logging, the log4j. The generic overrides feature provides a convenient means to insert, or make changes to, specific resources types used by an application and to continue using the existing ClassLoader and resource loading rules and behaviors for the application, without having to revise the application JAR files.
How WebLogic Logging Services Work The following sections describe the logging environment and provide an overview of the logging process. Components and Environment There are two basic components in any logging system: a component that produces log messages and another component to distribute publish messages.
In addition to using the message catalog framework, your application can use the following mechanisms to send messages to the WebLogic server log: weblogic. Server Logging Bridge WebLogic Server provides a mechanism by which your logging application can have its messages redirected to WebLogic logging services without the need to make code changes or implement any of the propriety WebLogic Logging APIs. Terminology Logger - A Logger object logs messages for a specific subsystem or application component.
If your application is configured for Java Logging or Log4j, in order to publish application events using WebLogic logging services, you can do either of the following: Recommended Configure your application's logger to use the Server Logging Bridge, which provides a lightweight means for your application's log messages to be redirected to WebLogic logging services without requiring any code changes.
Server Log Files and Domain Log Files Each WebLogic Server instance writes all messages from its subsystems and applications to a server log file that is located on the local host computer. How a Server Instance Forwards Messages to the Domain Log To forward messages to the domain log, each server instance broadcasts its log messages.
Note: This can result in a domain log file that lists messages with earlier timestamps after messages with later timestamps.
When messages from the buffer of a previously disconnected Managed Server are flushed to the Administration Server, those messages are simply appended to the domain log, even though they were generated before the previous messages in the domain log. Server Log The server log records information about events such as the startup and shutdown of servers, the deployment of new applications, or the failure of one or more subsystems.
Note: Oracle recommends that you do not modify log files by editing them manually. Modifying a file changes the timestamp and can confuse log file rotation. In addition, editing a file might lock it and prevent updates from WebLogic Server, as well as interfere with the Accessor. Subsystem Logs The server log messages and log file communicate events and conditions that affect the operation of the server or the application. Log Message Format When a WebLogic Server instance writes a message to the server log file, the first line of each message begins with followed by the message attributes.
If the message includes a stack trace, the stack trace is included in the message text. WebLogic Server uses the host computer's default character encoding for the messages it writes.
Message Attributes The messages for all WebLogic Server instances contain a consistent set of attributes as described in Table Table Server Log Message Attributes Attribute Description Locale-formatted Timestamp Time and date when the message originated, in a format that is specific to the locale.
Severity Indicates the degree of impact or seriousness of the event reported by the message. Machine Name is the DNS name of the computer that hosts the server instance. Log messages that are generated within a client JVM do not include this field. Transaction ID Present only for messages logged within the context of a transaction. Diagnostic Context ID Context information to correlate messages coming from a specific request or application.
Raw Time Value The timestamp in milliseconds. Message ID A unique six-digit identifier. Message Text A description of the event or condition. Message Severity The severity attribute of a WebLogic Server log message indicates the potential impact of the event or condition that the message reports. INFO Used for reporting normal operations; a low-level informational message. ALERT A particular service is in an unusable state while other parts of the system continue to function.
This severity indicates a severe system failure or panic. Note: Applications that use the com. The following information contained in the LogRecord determines how the log message is redirected: Message severity level The severity level is automatically converted to one of the standard WebLogic logging service severity levels when the log message redirected. Logger name The Server Logging Bridge handler publishes the application message to a logger in the WebLogic Logger tree matching the logger name contained in the LogRecord.
Log Level The Level of the LogRecord is automatically converted to one of the standard WebLogic logging service severity levels when the log message redirected. The ejb-jar. Additional deployment descriptors provide WebLogic-specific deployment information. A weblogic-cmp-rdbms-jar.
The weblogic-ejb-jar. Connectors also known as resource adapters contain the Java, and if necessary, the native modules required to interact with an Enterprise Information System EIS. To deploy a resource adapter to WebLogic Server, you must first create and configure WebLogic Server-specific deployment descriptor, weblogic-ra. Resource adapters can be deployed to WebLogic Server as stand-alone modules or as part of an Enterprise application.
See Enterprise Applications. An Enterprise application consists of one or more Web application modules, EJB modules, and resource adapters. It might also include a client application.
An Enterprise application is defined by an application. If the application includes WebLogic Server-specific extensions, the application is further defined by a weblogic-application. Enterprise Applications that include a client module will also have a client-application. For both production and development purposes, BEA recommends that you package and deploy even stand-alone Web applicatons, EJBs, and resource adapters as part of an Enterprise application.
Doing so allows you to take advantage of BEA's new split development directory structure, which greatly faciliates application development. It can be packaged as follows:. Web services can be shared by and used as modules of distributed Web-based applications.
They commonly interface with existing back-end applications, such as customer relationship management systems, order-processing systems, and so on. Web services can reside on different computers and can be implemented by vastly different technologies, but they are packaged and transported using standard Web protocols, such as HTTP, thus making them easily accessible by any user on the Web. The modules execute requests in WebLogic Server, not in the client.
WebLogic Server 8. A J2EE application client runs on a client machine and can provide a richer user interface than can be provided by a markup language. Application clients directly access Enterprise JavaBeans running in the business tier, and may, as appropriate communicate through HTTP with servlets running in the Web tier.
Modules and applications have deployment descriptors—XML documents—that describe the contents of the directory or JAR file. Deployment descriptors are text documents formatted with XML tags. BEA defines additional WebLogic-specific deployment descriptors for deploying a module or application in the WebLogic Server environment. Table lists the types of modules and applications and their J2EE-standard and WebLogic-specific deployment descriptors. See web. See weblogic.
See The weblogic-ejb-jar. See The weblogic-cmp-rdbms-jar. See the Sun Microsystems Connector 1. HTTP, weblogic. RMI, or an user-defined execute queue become stuck, the server changes its health state to warning. A subsystem is in critical state when a part of it is malfunctioning e.
Reason: java. NumberFormatException: null java. NumberFormatException: null at java. If an individual subsystem determines that it can no longer operate in a consistent and reliable manner, it registers its health state as failed with the host server and must be restarted. If a server finds one or more critical subsystems have reached this state, the server marks its own health state as failed.
0コメント