rasdaemon is the modern replacement for mcelog. RAS stands for Reliability, Availability, and Serviceability. It listens to the kernel's tracing subsystem and the EDAC (Error Detection And Correction) drivers, so it reports DIMM errors, PCIe AER events, and machine checks, and stores them in an SQLite database.

sudo dnf install rasdaemon            # or apt-get install rasdaemon
sudo systemctl enable --now rasdaemon

sudo ras-mc-ctl --status              # are the EDAC drivers loaded?
sudo ras-mc-ctl --summary             # counts per memory controller / DIMM
sudo ras-mc-ctl --errors              # detailed error log
sudo ras-mc-ctl --layout              # map of DIMM slots as the driver sees them

Corrected errors (CE) that keep occurring on the same DIMM location are a reason to schedule a replacement. Uncorrected errors (UE) need urgent attention. Hooks let you send alerts; check /etc/ras/.