Sample 0101 - Message Mediation Statistics

Introduction

This sample demonstrates how to set up an execution plan with a basic pass-through query. It selects some of the attributes of each incoming event and emits an output event with the selected attributes. This sample uses wso2event for both inputs and outputs.

The query used in this sample is as follows:

from InMediationStatsStream
select meta_host, timestamp, resource_id, direction, fault_count, count
insert into OutMediationStatsStream;

The above query,

• Processes the events received through the InMediationStatsStream
• Selects the attributes (meta_host, timestamp, resource_id, direction, fault_count, count) specified under the select clause, from each event received.
• Emits those events as output events through the OutMediationStatsStream.

Since we do not perform any processing apart from selecting a few attributes, this is considered as a pass-through query. 

Prerequisites

See Prerequisites in CEP Samples Setup page.

Building the sample

Start the WSO2 CEP server with the sample configuration numbered 0101. For instructions, see Starting sample CEP configurations. This sample configuration does the following:

• Creates <CEP_HOME>/repository/conf/stream-manager-config.xml file, which is used to create the stream definitions for the sample.
• Points the default Axis2 repo to <CEP_HOME>/sample/artifacts/0101 (by default, the Axis2 repo is <CEP_HOME>/repository/deployment/server).

Executing the sample

1. Open a new terminal, go to <CEP_HOME>/samples/consumers/wso2-event and run ant from there.
   
   It builds the sample wso2event consumer and executes it.

   Do not close this terminal. It is required to keep the server running and receiving events.

2. Open another terminal, go to <CEP_HOME>/samples/producers/mediation-stats and run ant from there.
   
   It builds and runs the wso2event producer, which will send mediation statistics data to the CEP server.

3. See the output events received from the CEP via the terminal opened in step 2.

   Note

   To configure host, port, username, password and number of events, use -Dhost=xxxx -Dport=xxxx -Dusername=xxxx -Dpassword=xxxx -Devents=xx.

   For example : ant -Devents=10

   For example, given below is a screenshot of the output of the consumer sending 5 events from the producer: