Have a long running Linux process open in a SSH terminal window and need to shutdown your computer without killing it? I run into this on a regular basis and never spent the time looking into a solution but this past weekend I actually decided to look and came up with a cool solution called reptyr. The reptyr application allows you to open screen and migrate the process to the screen terminal and away from the terminal connection opened without screen. This allows you to detach from the window without killing the process. Below is a quick overview of installing reptyr and how to use it.
I always forget the ps command arguments to see the length of time that a Linux process has been running so I am writing it out here in hopes of remembering it in the future without having to read the ps manpage. I also will know I can easily search this later to find the solution. Below I describe what command to use from a Linux terminal window to display the length of time a specific process or set of processes has been running.
A couple days ago I was printing a bunch of pictures from my laptop to my HP Photosmart 5100c for my father in-law. At one point I had run out of paper and other point had some other minor problem with the printer. After awhile I noticed that my computers CPU appeared to be fairly active even when I wasn’t doing anything so I started troubleshooting a bit to see what was going on.
Nagios is an awesome open source application that provides a way to monitor pretty much anything that you can think of on your network. There are tons of plugins written for Nagios that will monitor anything from PostgreSQL database size to the number of users logged into a server. Today I needed to start monitoring the size of a Ruby process that has been growing out of hand so the below is what I came up with being the best solution. Follow the directions below to deploy a Perl script that will use SNMP to retrieve Linux server process size.
A friend contacted me the other day because he was having an issue starting his development environment which consists of Ruby, PostgreSQL, and Mongrel. Ruby communicates with PostgreSQL using the postgres-pr gem version 0.6.1. Starting things using “ruby script/server” from within his Ruby project had been working for months without issue and there had been no confguration changes to Ruby, Postgres, or Mongrel so it appeared to not be configuration related. After getting a brief explanation of the issue I logged into his laptop and attempted to start the server. Below is the error received when attempting to start the server using “ruby script/server” via a terminal window on the Macbook Pro.