How to monitor your site from the console

Quite often I find myself with nothing but a console as access into any new Unix / Linux machine. Granted they are bad for some things but you will quickly find out that they are still the quickest and easiest way to get certain information from a system. You might be surprised to find that there are a load of great network and site monitoring tools out there that will run nicely over the console, take up no space and work like a charm. So to kick off Let me introduce the first one…

iftop

As the name might suggest to you ‘top’ but for interfaces (network interfaces). The simplest layout of them all – a monochrome readout telling you all of the hosts connected to the current interface (or another interface, use the -i option on the command line), how fast they are pulling information from the machine and the overall transmit and receive. Use this one if you have a site with some traffic and you want to see who are the biggest bandwidth hogs connected. This can be a useful one for debugging a site if it gets slow periodically (can be cron / load based or it can also be bot / hits based).

http://www.ex-parrot.com/pdw/iftop/

iptraf

This one is a little more involved than iptop. A full blown network statistics utility. If you have been using tcpdump in the past then you might want to give this one a shot also. You can monitor (in glorious console colour) traffic to the machine, interface statistics, statistical breakdowns and more. Add to this a really nice filter (with IP as one of the options) and you are onto a winner. Use this one if you want to get some more detail or check out traffic from a specific IP.

http://iptraf.seul.org/

apachetop

Whilst Google Analytics and other packages have made collecting information about your sites visitors super simple it is nice sometime to check out the hits as you are getting them. This is particularly interesting and useful in the optimisation process for any site. You can see what’s being called and in near realtime since apachetop keeps a track of all your logfiles. Click on the ‘h’ key whilst in there and you will get to see some interesting options such as how to get some detailed information about any of the requests. One of the most useful options is ‘n’ to switch from the bytes statistic to the HTTP return code value. Great for seeing where those 2xx, 3xx, 4xx and 5xx requests are coming from. Use this one also to check out what’s hot in realtime on your site, what pages are transmitting most frequently and which assets might be worth optimising.

http://code.google.com/p/apachetop/