The DSB is shipped with several components which allows service invocation monitoring which are detailled below.

h2. Short view

A collection of modules routers are in charge of intercepting messages on request, response and ACK (more details on what is a router module are given here). At these different steps, the modules add some monitoring information such as timestamp and other KPIs. One module is then dedicated of collecting these data and sending reports to a monitoring layer at different message exchange phases.

h2. Implementations

The DSB has its own monitoring collectors and APIs and is totally independent from any monitoring tools. This API can be found in module dsb-monitoring-api. Different implementations are provided by default and are listed below.

h3. EasierBSM implementation

A default implementation shipped with the default distribution is based on top of [EASIERBSM|easierbsm:EasierBSM - Open source Business Service Monitoring and SLA enforcement]. At the implementation level, it means that every time an endpoint is activated in the DSB, an endpoint registry listener sends a registration query to easierBSM. Then, each time a message is exchanged between a service consumer and provider, the DSB monitoring modules will send reports to easierBSM layer, translating DSB monitoring data to easierBSM one.

* monitoring.active=BOOLEAN where BOOLEAN is true or false: Activate or not monitoring by static configuration. Note: Changing this parameter value at runtime has no effect.
* monitoring.base=TBD
* monitoring.admin=URL where URL is the URL of the monitoring management endpoint ie the one which will receive the new registration query as described above.
* monitoring.listener=

h3. Web service notification implementation

Another monitoring implementation is based on Web service notification (WSN). Each time a message is exchanged between a service consumer and provider, a report is generated and sent to the internal WSN engine. If there are some subscribers which are interested in the monitoring data, they will be notified by the WSN engine with the monitoring data inside a WSN notify message such as:

An example of subscription payload can be

{code:language=xml}<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
<soapenv:Header />
<soapenv:Body>
<wsn:Subscribe xmlns:wsn="http://docs.oasis-open.org/wsn/b-2"
xmlns:add="http://www.w3.org/2005/08/addressing" targetnamespace="http://docs.oasis-open.org/wsn/b-2">
<wsn:ConsumerReference xmlns:wsn="http://docs.oasis-open.org/wsn/b-2"
xmlns:add="http://www.w3.org/2005/08/addressing">
<add:Address>http://localhost:9001/MonitoringSubscriber</add:Address>
</wsn:ConsumerReference>
<wsn:Filter>
<wsn:TopicExpression Dialect="http://www.w3.org/TR/1999/REC-xpath-19991116"
xmlns:dsb="http://www.petalslink.org/dsb/topicsns/">
dsb:MonitoringTopic
</wsn:TopicExpression>
</wsn:Filter>
</wsn:Subscribe>