Found that the real-time data stream hasn't been alive for the last 24 hours. No raw_data/isfs_ data files since 2022 01 05 04 00 and data_stats failed. This also caused webplots to fail. dsm_server was running, so check_cfact_procs didn't do anything. I just killed dsm_server and reran check_cfact_procs, which seems to have brought everything back to life.
As user isfs on barolo:
ps -ef | grep dsm (look for the process id of the dsmpgrep dsm_server process)
kill -9 <pid>
check_cfact_procs
...