udplistener

Overview ¶

Package udplistener implements a UDP listener. Given a target list, it listens for packets from each of the targets and reports number of packets successfully received in order, lost or delayed. It also uses the probe interval as an indicator for the number of packets we expect from each target. Use the "udp" probe as the counterpart with the same targets list and probe interval as the sender.

Notes:

Each probe has 3 goroutines:

• A recvLoop that keeps handling incoming packets and updates metrics.
• An outputLoop that ticks twice every statsExportInterval and outputs metrics.
• An echoLoop that receives incoming packets from recvLoop over a channel and echos back the packets.

• Targets list determines which packet sources are valid sources. It is updated in the outputLoop routine.
• We use the probe interval to determine the estimated number of packets that should be received. This number is the lower bound of the total number of packets "sent" by each source.