LVSmon

A cluster monitoring daemon, originally meant to replace tools like ldirectord and mon for maintaining LVS tables. Secure, reliable, scalable: it won't run away, won't give false output, and won't let anyone take over the system. Low CPU, small footprint, scales well despite running single-threaded.

Although built for Linux Virtual Servers, it runs on any POSIX platform with an ANSI C compiler.

Features

Edge-triggered status notification
Runs in a single non-blocking thread
Doesn't need to run as root
No dynamic allocation after entering the main loop
Very little memory (about 60 bytes per service monitored)
Scales reasonably well (poll-driven)
Provably correct design — will never run away with resources
Pauses 500ms before exiting on errors, to stop runaway interactions
Portable (ANSI C/POSIX)
Timeouts enforced on connect and receive events
Reports the nature of failures (e.g. connection refused)
HTTP plugin, checks responses per RFC 1945
Banner-checker plugin — works for SSH, SMTP, POP3, etc.

Downloads

The latest version is 0.0.2 (ChangeLog).
Version 0.0.2 — source
Version 0.0.1 — source

TODO

Better event reporting mechanism
Failure timeouts (e.g. 3 strikes and you're out)
Failure timeouts (e.g. no success for 5 minutes)
Support plugins that don't use TCP
More accurate timing
Support complex transactions
Make plugins actually pluggable
http: use getopt in plugins for option passing
Drop root privileges and chroot if started as root

Features

Downloads

TODO

License