The best practice is to check flow data on you flow server application. But sometimes you don’t need a flow server! Especially during troubleshooting. You can also check it from device cache. Because the device caches the data according to timers before exporting it to the server.
It's so basic and useful.
show flow monitor <monitor_map> cache location <location_lc>
And all other show commands are below
show flow exporter-map ..
show flow monitor-map ..
show sampler-map ..
show processes memory location <0/0/CPU0> | inc nfsvr
show flow monitor .. cache internal location <0/0/CPU0>
show flow exporter .. location <0/1/CPU0>
show flow platform producer statistics location <0/0/CPU0>
show flow platform nfea policer np <np_num> loc
<node-id>
show controller np ports all location <0/Y/CPU0>
show controller np count np<number> loc <0/Y/CPU0>