3 Application Tasks
The typical application tasks you can perform with Oracle Stream Analytics Visualizer, including managing event processing networks (EPNs), application lifecycle, Oracle CQL rules, and configuration history is introduced.
This chapter includes the following sections:
3.1 EPN Management
The Oracle Stream Analytics Event Processing Network (EPN) represents the interconnections between the various Oracle Stream Analytics components of an Oracle Stream Analytics application. Using Oracle Stream Analytics Visualizer, you can manage the EPN, including viewing and changing the configuration of a stage, recording and playing back events, and monitoring the throughput and latency of a stage or path. Right-click a stage to select common stage-related functions from a convenient context menu.
For more information, see:
3.2 Application Lifecycle Management
You can manage the full application lifecycle including uploading an application, deploying it, suspending and resuming the application, and undeploying the application.
For more information, see Application Lifecycle.
3.3 Rules Management
You can create, replace, and delete the rules in the Oracle CQL processors of Oracle Stream Analytics applications you develop and deploy as well as applications that Oracle Stream Analytics server deploys.
It is important to note that Oracle Stream Analytics Visualizer will update your configuration file on the server with any queries that you create. However, you will not see this take effect in your application from within the Oracle JDeveloper, in order to make the change there you will need to copy and paste the query from Oracle Stream Analytics Visualizer into your application.
For more information, see Oracle CQL Rules.
3.4 Configuration History Management
Using the Oracle Stream Analytics Visualizer, you can manage the configuration changes you make to Oracle Stream Analytics components. You can review change history and you can undo (roll back) changes to an earlier version. You can perform these operations on a given resource or application in both standalone-server and multiserver domains.
Alternatively, you can manage configuration history
using the wlevs.Admin command-line tool.
For more information, see:
-
Overview of
wlevs.AdminUtility in Administering Oracle Stream Analytics.
3.4.1 Enable and Disable Configuration History Management
By default, Oracle Stream Analytics provides resource and application configuration history management.
Optionally, you can disable this feature by editing the startwlevs script for the server and adding the com.oracle.ocep.config.version.enabled system property to the last line (in practice, the command should be on one line):
"$JAVA_HOME/bin/java" $JVM_ARGS $DEBUG_ARGS -Dwlevs.home="$USER_INSTALL_DIR"
-Dcom.oracle.ocep.config.version.enabled=false -Dbea.home="$BEA_HOME"
-jar "${USER_INSTALL_DIR}/bin/wlevs.jar" $ARGS
If you disable this feature, Oracle Stream Analytics cannot propagate rules among the Oracle Stream Analytics servers in a multiserver domain. In this case, to propagate rule changes, you must manually update the rules in all the servers of a multiserver domain.
If you disable this feature and then wish to re-enable it, you must do so as follows:
3.4.2 Configure Change Record Purge Behavior
You can set how often change records in the configuration history are purged, along with how many records are retained on each purge (in other words, records not purged). You might use these settings for enhancing performance. Purging more often and retaining fewer records might improve performance in some cases, such as when your application makes a large number of configuration changes dynamically at run time.
You configure these settings with system properties that you pass when starting the Oracle Stream Analytics server. The system properties are as follows:
-
com.oracle.ocep.config.version.changeRecordsPurgeFrequency-- Amount of time, in seconds, between each purge. Default value is 3600 (one hour). -
com.oracle.ocep.config.version.numSavedChangeRecords-- Number of change records that will be saved when purging old change records. Default value is 25.
To make these settings, edit the startwlevs.cmd script for the server to add the system property to the last line (in actual practice, the command should be on one line).
For example, to set the purge frequency to 10 minutes and retain 50 records, you could use a command such as the following:
"$JAVA_HOME/bin/java" $JVM_ARGS $DEBUG_ARGS -Dwlevs.home="$USER_INSTALL_DIR" -Dcom.oracle.ocep.config.version.changeRecordsPurgeFrequency=600 -Dcom.oracle.ocep.config.version.numSaveChangeRecords=50 -Dbea.home="$BEA_HOME" -jar "${USER_INSTALL_DIR}/bin/wlevs.jar" $ARGS
You must restart the Oracle Stream Analytics server to have your changes take affect.
3.4.3 Resource Configuration History Management
You can manage the configuration history of the following Oracle Stream Analytics resources:
-
Oracle Stream Analytics high availability adapters
-
Oracle CQL rules
For more information, see Manage Resource Configuration History.
3.4.4 Application Configuration History Management
You can manage the configuration history for a given application. This allows you to see a summary of all the configuration changes made to all resources of a given application.
For more information, see Manage Application Configuration History.
3.4.5 Application Lifecycle and Configuration History Management
When you deploy an application, the Oracle Stream Analytics server creates a new configuration history for the application.
When you update an application, the Oracle Stream Analytics server erases the existing configuration history and creates a new configuration history for the application.
When you uninstall an application, the Oracle Stream Analytics server erases the configuration history for the application.
For more information, see Application Lifecycle Management.
3.4.6 Multiserver Domains and Configuration History Management
When you deploy an application to a multiserver domain, consider the following configuration history management restrictions:
For more information, see Multiserver Domain Management.
3.4.6.1 Rejoin a Multiserver Domain
When an Oracle Stream Analytics server joins (or rejoins) a multiserver domain, the server's existing configuration history records (if any) are deleted and replaced with the current multiserver domain configuration history when the Oracle Stream Analytics server has synchronized with the primary.