On: Don’t break the Internet with your Javascript

[dredmorbius]

Our java engine (Jetty) logs 200s even when it's generating 500s.

Learn me to trust my own fucking logs, will you.

One of the more useful monitoring tools I've got is a simple shell-wrapped "HEAD" script that polls our cluster and reports an "OK" or "ERR" (slow responses trigger a "Hrm..", along with the current, median, and standard deviation of the response, and total error counts. That sits in an omnipresent, always-on-top small-font terminal window.

Something like:

      2012-03-30 12:03   i=9948
    Host    Status  Cur   Med   sd     Err
    www     OK      0.22  0.24  0.44    6

[rhizome → dredmorbius]

That is the basic mechanism behind load-balancer healthchecks.

[dredmorbius → rhizome]

That and connection tracking.