Setting up Service Statistics Data Agent

BAM Service Data Agent is used to collect statistics related to service data from WSO2 service-hosting products (such as WSO2 Application Server (AS), WSO2 Data Services Server (DSS), WSO2 ESB, WSO2 Business Process Server (BPS), WSO2 Business Rules Server (BRS)) and send to the WSO2 BAM server. BAM server receives data events via its Thrift API. This protocol uses a binary protocol and enables fast data transmission between the service-publishing products and BAM server. BAM Service Data Agent can be configured early so that the statistics to be extracted from service data of the service-publishing product can be pre-defined. In the configuration panel, the user can specify the BAM server (Thrift server) related information and properties to be extracted from services. The user should define the Event Stream related parameters uniquely identified by a name and a version.

The following sections are covered:

Installing required features

1. Download the WSO2 Application Server or any other server you wish to monitor. We will assume WSO2 AS is downloaded and refer to the same as AS for the rest of the document.

2. As we are running both AS and BAM server concurrently we should change the port number of AS by applying an offset. In order to apply an offset, in the AS product directory go to $as_home/repository/conf and open file, carbon.xml. Then change the value in xpath Server/Ports/Offset from 0 to some other integer. For example,

<!-- Ports offset. This entry will set the value of the ports defined below to the define value + Offset. e.g. Offset=2 and HTTPS port=9443 will set the effective HTTPS port to 9445 -->

<Offset>2</Offset>

3. To start the server,

• on Linux: sh wso2server.sh
• on MS Windows: wso2server.bat

4. In the management console, select "Configure -> Features" and click the "Repository Management" tab. Then select a P2 repository either from a URL or a file. For instructions, refer to section Managing the Feature Repository .

For example,

 

5.Then click "Add".

6.Click Installed Features. You see the BAM Service Data Agent Aggregate feature installed by default from the added P2 repository as shown below.

 

 7. Go to <WSO2 Application Server home>/repository/conf/etc and open bam.xml file and enable ServiceDataPublishing as follows:

<BamConfig>   
     <ServiceDataPublishing>enable</ServiceDataPublishing>
</BamConfig>

This is disabled by default, and BAM publishing won't occur even if you proceed with the rest of the steps if not explicitly enabled.

8. Restart the WSO2 AS server. (Go to "Shutdown/restart" sub menu of the "Main" menu in the management console).  

Configuring Service Data Agent

Follow the instructions below to setup service data publishing in a running WSO2 AS Carbon instance.

Using on-premise deployment of WSO2 AS

If you are using an on-premise deployment of WSO2 AS, follow the below steps to configure the service data publishing capability, which is provided in the WSO2 feature repository:

1. Log in to the Application Server management console and select "Service Data Publishing" from the "Configure" menu.

3. The "Service Data Publisher Configuration" window opens. Fill it appropriately. For example,

Enable Service stats: Tick to get the activity statistics. 

Stream Definition Configuration:

• Stream Name: Stream Name can be any string with alpha-numeric characters
• Version: Stream Version distinguishes different streams with the same Stream Name. Default version should be 1.0.0 . If the service statistics toolbox is installed, the version should be different to 1.0.0 since the default toolbox uses version 1.0.0 for the stream definition to enable service statistics only.
  
• Nick Name: This is a user preferred nick name to the Stream Name in alpha-numeric characters
• Description: A description describing about the particular stream defined by Stream Name, Stream Version pair. Description should also consists of alpha-numeric characters.

BAM Credentials:

• BAM URL: Enter the IP address of the BAM server. And the port should be the thrift port ( ex: tcp://127.0.0.1:7611 ). You can add a comma-separated list of server URLs to ensure that load is distributed among many servers and to minimize effects of a failure of one server node. This load balancing feature is an enhancement of the BAM 2.0.1 release onwards.
• Username: Put the BAM Thrift log-in user name. Default value is admin.
• Password: Put the BAM Thrift log-in password. Default value is admin.

Properties: A BAM deployment can receive events from different data agents. In order to uniquely identify events triggering from one agent, a property can be associated it. This feature is particularly useful in clustered environment.

Click the "Update" button once done.

Using Cloud deployment of WSO2 AS

In a cloud deployment of WSO2 AS, it is not required to enable data publishing to BAM using the 'BAM Service Data Agent Aggregate' feature as explained above. Instead, you can simply add the BAM url to the <AS_HOME>/repository/conf/carbon.xml file as shown below.

<BamServerURL>https://bamhost:bamport/services/</BamServerURL> 

Note that cloud deployment is enabled by the following setting in the <AS_HOME>/repository/conf/carbon.xml file:

<IsCloudDeployment>true</IsCloudDeployment>

Monitoring a sample Web service

1. Log in to the Application Server management console and select "Services -> List" in the "Main" menu.
   
2. In the "Deployed Services" window that opens, click the "TryIt" option of the "HelloService".
   
3. In the Try It UI, add a sample string as "name" and click the "Send" button.
   
4. To view data in the Cassandra database using the Cassandra Explorer, in the management console click Tools, and then click Connect to Cluster in the Cassandra Explorer menu.
5. Enter the connection details as shown below, and click Connect.
   
   
   • Connection Url: connection url of the Cassandra cluster with ip and port. For example, localhost:9160 if you didn't set a port offset, and 10.8.99.101:9161 if you have set a port offset of one. This field is mandatory.
   • Username: username of the Cassandra cluster. 
   • Password: password of the Cassandra cluster. 
   • Maximum Result Count: maximum results retrieved from the Cassandra cluster. The default value is 1000.
6. BAM data agent sends the message  from the service hosting product to the column family with the given stream name in  the EVENT_KS  key-space of the Cassandra database as shown below.
   

Analyzing service statistics

BAM service statistics data agent extracts the statistics information about the request came for a Axis2 service in WSO2 server, and publishes the statistics information to BAM. In service statistics each request will publish the event to BAM along with it's statistical data. With default configuration of BAM service statistics data agent the following measures are published. As mentioned above,  BAM service statistics agent will send event for every request. Therefore the the below event meta, payload data of service statistics belongs to per service request.