Configuring and Using the WebLogic Diagnostic Framework

Accessing Diagnostic Data Using the Data Accessor

The Data Accessor component of the WebLogic Diagnostic Framework (WLDF) provides the means for accessing diagnostic data from various sources, including log records, data events, and harvested metrics.

Using the Data Accessor, you can perform data lookups by type, component, and attribute. You can perform time-based filtering and, when accessing events, filtering by severity, source, and content. You can also access diagnostic data in tabular form.

The following sections describe the Data Accessor and tell how to use it online (when a server is running) and offline (when a server is not running):

• About the Data Stores Accessed by the Data Accessor
• Accessing Diagnostic Data Online
• Accessing Diagnostic Data Offline

 

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About the Data Stores Accessed by the Data Accessor

The data accessor retrieves diagnostic information from other WLDF components. Captured information is segregated into logical data stores that are separated by the types of diagnostic data. For example, server logs, HTTP logs, and harvested metrics are captured in separate data stores.

WLDF maintains diagnostic data on a per-server basis. Therefore, the Data Accessor provides access to data stores for individual servers.

Data stores can be modeled as tabular data. Each record in the table represents one item, and the columns describe characteristics of the item. Different data stores may have different columns. However, most data stores have some of the same columns, such as the time when the data was collected.

The Data Accessor can retrieve the following information about data stores used by WLDF for a server:

• A list of supported data store types, including:
• HTTP_LOG
• HARVESTED_DATA_ARCHIVE
• EVENTS_DATA_ARCHIVE
• SERVER_LOG
• DOMAIN_LOG
• HTTP_ACCESS_LOG
• WEBAPP_LOG
• CONNECTOR_LOG
• JMS_MESSAGE_LOG
• CUSTOM_LOG
• A list of available data store instances
• The layout of each data store (information that describes the columns in the data store)

You can use the WLDFAccessRuntimeMBean to discover such data stores, determine the nature of the data they contain, and access their data selectively using a query.

For complete documentation about WebLogic logs, see Configuring Log Files and Filtering Log Messages.

 

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Accessing Diagnostic Data Online

You can access diagnostic data from a running server by using the Administration Console, JMX APIs, or the WebLogic Scripting Tool (WLST).

Accessing Data Using the Administration Console

You don't use the Data Accessor explicitly in the Administration Console, but information collected by the accessor is displayed, for example, in the Summary of Log Files page. See View and Configure Logs in the Administration Console Online Help.

Accessing Data Programmatically Using Runtime MBeans

The Data Accessor provides the following runtime MBeans for discovering data stores and retrieving data from them:

• Use the WLDFAccessRuntimeMBean to do the following:
• Get the logical names of the available data stores on the server.
• Look up a WLDFDataAccessRuntimeMBean to access the data from a specific data source, based on its logical name. The different data stores are uniquely identified by their logical names.

See WLDFAccessRuntimeMBean in the WebLogic Server MBean Reference.

• Use the WLDFDataAccessRuntimeMBean to retrieve data stores based on a search condition, or query. You can optionally specify a time interval with the query, to retrieve data records within a specified time duration. This MBean provides meta-data about the columns of the data set and the earliest and latest timestamp of the records in the data store.

Data Accessor runtime mbeans are currently created and registered lazily. So, when a remote client attempts to access them, they may not be present and an InstanceNotFoundException may be thrown.

The client can retrieve the WLDFDataAccessRuntimes attribute of the WLDFAccessRuntime to cause all known data access runtimes to be created, for example:

  ObjectName objName = 
      new ObjectName("com.bea:ServerRuntime=" + serverName + 
                      ",Name=Accessor," +
                      "Type=WLDFAccessRuntime," +
                      "WLDFRuntime=WLDFRuntime"); 
  rmbs.getAttribute(objName, "WLDFDataAccessRuntimes");

See WLDFDataAccessRuntimeMBean in the WebLogic Server MBean Reference.

Note: If the clock on a server hosting a WebLogic Server instance is reset, it can give you unexpected results when you query based on a timestamp.

Using WLST to Access Diagnostic Data Online

Use the WLST exportDiagnosticDataFromServer command to access diagnostic data from a running server. For the syntax and examples of this command, see Diagnostic Commands, in the WLST Command and Variable Reference.

Using the WLDF Query Language with the Data Accessor

To query data from data stores, use the WLDF query language. For Data Accessor query language syntax, see WLDF Query Language.

 

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Accessing Diagnostic Data Offline

Use the WLST exportDiagnosticData command to access historical diagnostic data from an offline server. For the syntax and examples of this command, see "Diagnostics Commands in the WLST Command and Variable Reference.

Notes: You can use exportDiagnosticData to access archived data only from the machine on which the data is persisted.

You cannot discover data store instances using the offline mode of the Data Accessor. You must already know what they are.