Identifying slow nodes in distributed applications

A network interface controller (NIC) of a node, comprising:

• a traffic-monitoring circuit to monitor traffic through the NIC by measuring durations of one or more non-paused idle periods in response to receiving a trigger signal;
• a plurality of counters corresponding to a plurality of idle-period duration ranges, a respective counter to be incremented in response to the traffic-monitoring circuit determining that a duration of a non-paused idle period falls within a corresponding idle-period duration range;
• and
• a histogram-generation circuit to generate a histogram for the node based on counter values corresponding to a plurality of idle-period duration ranges, the histogram to facilitate identification of one or more slow nodes within a plurality of nodes executing a distributed application.

A non-transitory machine-readable storage medium storing instructions executable by a processing resource to:

• configure a network interface controller (NIC) of a compute node to, in response to receiving a trigger signal, monitor traffic to or from the compute node by measuring durations of one or more non-paused idle periods;
• configure the NIC to increment a counter in response to determining that a duration of a non-paused idle period falls within a corresponding idle-period duration range;
• configure the NIC to generate a histogram for the compute node based on counter values corresponding to a plurality of idle-period duration ranges;
• and
• identify one or more slow nodes among a plurality of compute nodes executing a distributed application based on histograms associated with the plurality of compute nodes.