active pulse
heartbeats
h-signal
data pulse
Answer is Wrong!
Answer is Right!
The correct answer is: B. heartbeats
NameNode and DataNode do communicate using heartbeats. Heartbeats are a way for the NameNode to keep track of the DataNodes in the cluster. The NameNode sends out heartbeats to the DataNodes at regular intervals, and the
124.1c-6.3-23.7-24.8-42.3-48.3-48.6C458.8 64 288 64 288 64S117.2 64 74.6 75.5c-23.5 6.3-42 24.9-48.3 48.6-11.4 42.9-11.4 132.3-11.4 132.3s0 89.4 11.4 132.3c6.3 23.7 24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.2 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z"/>
Subscribe on YouTube
DataNodes respond with heartbeats to acknowledge that they are alive. If the NameNode does not receive a heartbeat from a DataNode for a certain period of time, it will assume that the DataNode is dead and will remove it from the cluster.
Active pulse is a term used in electronics to describe a signal that is constantly on. This is in contrast to a passive pulse, which is a signal that is only on for a short period of time. H-signal is a term used in telecommunications to describe a signal that is used to carry data. Data pulse is a term used in computer science to describe a signal that is used to carry data.
In conclusion, the correct answer is: B. heartbeats.