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 installation instructions specifically refer to the WSO2 Application Server version 5.x.x. Similar instructions apply to any other service-hosting WSO2 server based on Carbon 4.0.x.
The following sections are covered:
Installing the Feature (This feature is packaged default with WSO2 AS. If required for other servers follow this section.)
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,
3. To start the server,
- on Linux 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.
Then click "Add".
5. Go to "Available Features" tab and select the repository added above. The, click on "Find Features" button. From the list of features that appears, select "BAM Service Data Agent Aggregate" feature and click "Install."
6. Click "Next" and accept the license agreement.
7. Restart the WSO2 AS server. (Go to "Shutdown/restart" sub menu of the "Main" menu in the management console).
Configuring Service Data Agent
1. Go to <WSO2 Application Server home>/repository/conf/etc and open bam.xml file and enable ServiceDataPublishing as follows:
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.
2. 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.
Enable Activity Service: This enables message tracing with BAM. Typically, a request is sent to an endpoint after being passed through some intermediate stages. Messaging tracing enables to track each messages and visualize the message body in each of these intermediate stages.
Enable Activity Service feature will be implemented from the next release of BAM.
Stream Definition Configuration:
- Strea m Na me: 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 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.
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. BAM Data Agent will send the message from the service hosting product to the column family with the given "Stream Name" in key-space, "EVENT_KS" in the Cassandra database. Data in the Cassandra database can be seen from the "Cassandra Explorer" in the BAM server using the management console. (Main -> Cassandra Explorer -> List Keyspaces)
What does Service Statistics Tell?
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.
|Event Property Name||Type||Description|
Content type of the incoming request for the axis2 service deployed in WSO2 server (Eg: WSO2 AS)
Host name of the service hosting server (Eg: WSO2 AS)
It's the HTTP header field that indicates from which the request came to the axis2 service deployed in the WSO2 server (Eg: WSO2 AS)
|Meta Data||The remote address of the axis2 service deployed WSO2 server (Eg: WSO2 AS)|
|Meta Data||Service Endpoint of the axis2 service, for which the request came.|
|Meta Data||It is a HTTP header field which represents the software program used by the original client. (Eg: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:11.0) Gecko/20100101 Firefox/11.0)|
|Payload Data||If the message has been encountered any fault when serving the request, then this will be incremented as 1. If request successfully served, this count will be 0.|
|Payload Data||The operation name for which the request has been made to, in the axis2 service.|
|Payload Data||The request count will be incremented to 1, if the request has been reached the WSO2 service hosting server. (Eg: WSO2 AS)|
|Payload Data||The response count will be incremented by 1, if the refer axis2 service request is successfully served without any error and returned the response to the client. Else it will remain 0.|
|payload_response_time||Payload Data||The time taken for the axis2 service to serve the request and send back a response.|
|payload_service_name||Payload Data||The service name for which the request came in.|
|payload_timestamp||Payload Data||The time of when the request came into WSO2 service hosting server (WSO2 AS), not the time which the event was received by BAM server.|