Ask most engineers familiar with JunOS, and they will tout the benefits of a modular operating system. All too many forget this though, when it comes to actual operation of the device. In production networks, sometimes processes fail, and a simple restart of the process can help to prevent having to reboot the device. I have had quite a bit of success restarting some processes in order to avoid having to restart a device, especially with the EX switch product line. The syntax looks like:
autoinstallation Autoinstallation process chassis-control Chassis control process class-of-service Class-of-service process database-replication Database Replication process dhcp Dynamic Host Configuration Protocol process dhcp-service Dynamic Host Configuration Protocol process diameter-service Diameter process dot1x-protocol Port based Network Access Control ethernet-link-fault-management Ethernet OAM Link-Fault-Management process ethernet-switching Ethernet Switching Process event-processing Event processing process firewall Firewall process general-authentication-service General authentication process gracefully Gracefully restart the process immediately Immediately restart (SIGKILL) the process interface-control Interface control process kernel-replication Kernel replication process l2-learning Layer 2 address flooding and learning process lacp Link Aggregation Control Protocol process license-service Feature license management process link-management Link management process lldpd-service Link Layer Discovery Protocol mib-process Management Information Base II process mountd-service Service for NFS mounts requests multicast-snooping Multicast Snooping process pgm Pragmatic General Multicast process redundancy-interface-process Redundancy interface management process remote-operations Remote operations process routing Routing protocol process secure-neighbor-discovery Secure Neighbor Discovery Protocol process service-deployment Service Deployment System (SDX) process sflow-service Flow Sampling (Sflow) Daemon snmp Simple Network Management Protocol process soft Soft reset (SIGHUP) the process vrrp Virtual Router Redundancy Protocol process web-management Web management process
Examples of processes I have successfully restarted to fix problems are:
Not always ideal to have to do this, but in the event that you do, it can be the difference between fixing things quickly, and a true user-perceptible outage.