Constrained Application Protocol (CoAP) is a web transfer protocol designed for machine-to-machine devices. The CoAP Server origin is a multithreaded origin that listens on a CoAP endpoint and processes the contents of all authorized CoAP requests.
The CoAP Server origin can use multiple threads to enable parallel processing of data from multiple CoAP clients.
Before you configure the origin, perform additional steps to configure the CoAP clients.
When you configure the CoAP Server origin, you specify the maximum number of concurrent requests to determine how many threads to use. You also define the listening port and resource name for the origin. You can optionally override the default values of network configuration properties.
Before you run a pipeline with the CoAP Server origin, configure the CoAP clients to send data to the CoAP Server listening port and resource.
When you configure the CoAP Server origin, you define a listening port number where the origin listens for data. You also define the resource name used to pass requests to the origin. To pass data to the pipeline, configure each CoAP client to send data to a URL that includes the listening port number and resource name.
coap://<sdc_hostname>:<listening_port>/<resource_name>
The URL includes the following components:
For example: coap://localhost:5683/sdc
The CoAP Server origin performs parallel processing and enables the creation of a multithreaded pipeline.
The CoAP Server origin uses multiple concurrent threads based on the Max Concurrent Requests property. Each thread connects to the origin system and creates a batch of data, and passes the batch to an available pipeline runner.
A pipeline runner is a sourceless pipeline instance - an instance of the pipeline that includes all of the processors and destinations in the pipeline and represents all pipeline processing after the origin. Each pipeline runner processes one batch at a time, just like a pipeline that runs on a single thread. When the flow of data slows, the pipeline runners wait idly until they are needed.
Multithreaded pipelines preserve the order of records within each batch, just like a single-threaded pipeline. But since batches are processed by different pipeline instances, the order that batches are written to destinations is not ensured.
For example, say you set the Max Concurrent Requests property to 5. When you start the pipeline, the origin creates five threads, and Data Collector creates a matching number of pipeline runners. Upon receiving data, the origin passes a batch to each of the pipeline runners for processing.
At any given moment, the five pipeline runners can each process a batch, so this multithreaded pipeline processes up to five batches at a time. When incoming data slows, the pipeline runners sit idle, available for use as soon as the data flow increases.
For more information about multithreaded pipelines, see Multithreaded Pipeline Overview.
The CoAP Server origin uses the default values for network configuration properties as implemented by Eclipse Californium. If needed, you can override the default values of these properties.
For example, the origin uses the default value of 2000 for the ACK_TIMEOUT network configuration property. To override the default value, add ACK_TIMEOUT as an additional network configuration property and set the property to the desired value, such as 1000.
The CoAP Server origin processes data differently based on the data format that you select. The origin processes the following types of data:
Configure a CoAP Server origin to generate multiple threads for parallel processing of CoAP client requests.