logger_lib_dpdk

Basic Purpose:

This is a logger library built on top of DPDK for use in 5G applications. Its main purpose is to create a logger class capable of handling all the logging related utilities in the 3GPP TS 38.314 V16.2.0 (2020-12) technical specifications. Library uses meson to configure itself and adds dpdk as system dependency. Current meson configuration also creates a .so file so it can be added as a library easily.

Usage:

Class uses rte_metrics and rte_timer libraries in the background and handles interaction with these libraries. All these libraries require initialization in a primary process so logger library should be initialized after EAL is initialized.

Example:

    ret = rte_eal_init(argc, argv);
	if (ret < 0)
		rte_panic("Cannot init EAL\n");
	logger = new LoggerLib(rte_socket_id());

Class also provides a convenient Tick function to be called to handle necessary timer callbacks. This callback internally uses callbacks from the rte_timer library. This means calling this function handles all timer callbacks for all registered timers inside or outside of the logger class.

    static int lcore_task(void *arg){
        // Handle Task related initializations
        ...
        while (1)
	    {
	        // Handle other recurring tasks
	        ...
	        // Handle Timer Callbacks
		    logger->LoggerTick();
	    }
	}

Current Capabilities

Class is now able to handle PRACH request made to each SSB or cell. It is section 4.2.2.1 and 4.2.2.2 in the technical specifications. There is only a single interface for SSB's in the API but cell functionality is exactly the same so they can be used interchangibly. Functions to handle these logging activities can be found at the logger_lib.h header file. Sampling of these values are fixed at 1Hz and a callback is triggered every second to generate the logged data. User can access the last sampled data or current data if needed but specifications only mentions the sampled data.

Library also has a prototype for handling logging of UE contexes per DRB per cell. This is section 4.2.1.3 in the technical specification. Library currently handles the metric registration and adding new active or inactive UE contexes. It does not handle deletion and timer callback still has couple of things more to handle.

Metric Interface Class

Library uses an adapter class called MetricInterface to handle any requests to raw metric storage. logger_lib handles the access to raw metric storage and extracts necessary data from stored information. Right now, a metric interface for rte_metrics library is implemented. This library is a wrapper around rte_mempool provided by dpdk and simplifies memory access for metric handling. Using this library however, results in a larger memory footprint and in the future, implementing a metric interface directly on top of rte_mempool can be considered.