A really useful Juniper Engineering command that takes a snapshot and adds it to your syslog. The following is a command for cpu and memory monitor.
From the command line:
2010-09-01 12:00:15 CPU Memory Monitor: CPU: 45% free Memory: 30000000 bytes free
To enable logging of the CPU and memory usage, enter the following CLI commands (disabled by default):
configure cpu-memory-monitor set enable [duration <minutes>]
The duration of the logging interval defaults to 30 minutes (10 is the minimum).
To disable logging of the CPU and memory usage:
configure cpu-memory-monitor set disable