Ask HN: What do you use to monitor your web application?

https://news.ycombinator.com/item?id=1123172

by boundlessdreamz • 16 years ago

37 18 16 years ago

news.ycombinator.com

What do you use to monitor

1. Requests/second

2. Average Request Time

3. Exceptions

3. Background Queues

4. Mysql/Postgres servers

5. Uptime

6. Memory usage

7. Disk usage

If you have any tips/scripts/tutorials, please share :)

spooneybarger• 16 years ago

Our primary means of monitoring is to do fullpage requests to different parts of the application every 5 minutes and check the results. We have a historical record from multiple locations around the world that we can use to see if changes were made that had a negative impact as well as automated alerts when the full page load takes longer than expected.

We then have secondary monitoring that can allow use to isolate issues within different areas if primary monitoring indicates a problem.

dpritchett• 16 years ago

I have trouble imagining something more useful than Munin for a *nix server. Check out this screenshot - it only shows four of the tens of graphs available at any given time: http://dpritchett.posterous.com/test-driving-munin-service-s...

Edit: Munin profiles services and responsiveness. You'll probably want to complement it with Nagios to monitor service/hardware failures.

aw3c2• 16 years ago

I use Munin even on my local work computer.

And vnstat for realtime and aggregated network traffic. Conky for volatile realtime cpu/ram/etc.

dangrossman• 16 years ago

A Windows 7/Vista desktop gadget. Actually, the gadget is just a tiny (400x300ish) iframe showing a webpage with some small text. It sits in the corner of one of my monitors where I can always see it.

This webpage is a list of servers (front and back end) and their load averages.

At least for all the webapps I run, which serve hundreds of requests per second to tens of thousands of users, load average is a good enough proxy for all the metrics that matter.

When CPU usage on the front end servers is getting high enough that it impacts response times and throughput, that shows up in the increasing load averages. When disk IO on the database servers is getting high enough that it impacts response times and thoughput, that shows up in the increasing load averages.

The web servers each have a webpage on them that has the load average as its only output. I wrote up a little script for the database servers to query the load remotely on the DB servers. The webpage I use as the desktop gadget polls those webpages/scripts and prints out the server names and their current load as its output.

As for uptime monitoring when I'm not around, I used to use AreMySitesUp.com. Nice, simple service that does what it's supposed to. Even with a free plan it seems to check every 15 minutes or more often, and if a site goes down, it checks again much more often until it comes back up. It'll also tell you the exact status code if it's not in the 200-300 range, so you can tell a server is 500'ing out but online, and will notify you of timeouts.

I built my own uptime monitoring service, though, so I don't need that anymore. I run it using VPS accounts at different providers so I don't get stuck with the sites and the service monitoring them going down at the same time. Twilio just added SMS to their API, so adding SMS alerts to any custom monitoring scripts is dead easy now.

fseek• 16 years ago

I would say all of them. Generally top + atop + the log files should be enough.

rajuvegesna• 16 years ago

If you are looking for some commercial solutions, there are ton of them like AppManager (appmanager.com). But then, some of these solutions monitor what you expose from your application.

I don't know if there are any hosted solutions though.

dmytton• 16 years ago

These are all important metrics but they're available from different things.

You will have application specific metrics - errors, user counts, message queue sizes. These will help you understand what is happening in the app itself, let you fix problems and ensure that things are running smoothly. For this we use FogBugz to report errors and have various user metrics store in a database.

The next level is the daemons and services used by the application. Apache will report the number of req/s and MySQL can tell you about the number of connections, or the status of replication. These are important for planning growth and ensuring your server capacity is sufficient.

Then there's the servers themselves. This is CPU load, memory usage, disk usage, etc. This ties closely to the services above.

There are a lot of tools for doing these things, but in the end you have to tie everything together yourself. You might start with simple website response monitoring with something like http://www.pingdom.com then move on to having it triggering your own check scripts to alert you when custom stuff goes wrong (e.g. queue sizes).

And of course I'd recommend my company's server monitoring product http://www.serverdensity.com ;) but you could spend some time setting up a bigger, more flexible (and thus more complex) tool such as Nagios to pull all the metrics in.

dryicerx• 16 years ago

If you're addicted to every statistic possible, check out collectd http://collectd.org/ . It's a tiny daemon that polls every couple of seconds pretty much every server and services stat imaginable (cpu, mem, disk, snmp from routers, get vals over http from your app, apache, *sql, etc) without really any noticeable performance hit. You can output it all RRD files and view it in a variety of ways. You can also use use cacti, munin (by them selves to collect and graph, or use collectd to collect and use either of these to graph as well)

imagetic• 16 years ago

http://newrelic.com has been pretty critical, but we're a Rails only shop.

briandoll• 16 years ago

+1 for New Relic

I wouldn't consider building a production Rails app without it.

boundlessdreamz• 16 years ago

I've testing scout as well. Was easy to setup. Interface could use a bit of work though.

sunkencity• 16 years ago

Nagios - measuring that the application and database is up, and that disk and load are ok. (also ping but that is redundant).

I use exception notifier for rails. Simple, but it works. Might switch to newrelic.

From time to time I also use pingdom.com to see that the site is available from different networks around the globe.

ianmcgowan• 16 years ago

It's early development (pre-alpha), but http://www.leemba.com/ looks promising.

mrj• 16 years ago

Check out the demo (it's currently on a virtual host so it might get destroyed :-)

http://demo.leemba.com/

doriang• 16 years ago

ScriptCanary - monitors Javascript errors

wooster• 16 years ago

For stats, I use Ganglia. The newest versions, which sadly have to be installed from source on most Linux variants, have support for Python modules. So, in addition to the out of the box stuff, I monitor a whole bunch of other stuff related to how my applications are doing (signups, item counts, etc).

For daemon monitoring and watchdog-ing, I use monit. It emails me if there are problems with the server, and can automatically restart processes if they fail or get out of control.

chuhnk• 16 years ago

1. I dont actively use Apache extended status or req/sec monitoring because it slows down serving requests. Instead I look in the logs every minute and feed the count into ganglia.

2. Again apache logs into ganglia. New Relic for rails. Firebug and yslow when testing.

3. Exception notifier in rails, ErrorDocument in apache that triggers a php script which notifies by email. Log4j in java.

4. Redis, OpenMQ for queueing, Resque for background jobs

5. MySQL only because at the time postgres did not support replication.

6. AlertSite

7. Monit

8. Monit

I am always on the look out for better ways to monitor the servers at work. I never really liked nagios. Monit is extremely easy to use and is very good at what it does. MMonit is a management console that can centralize the monitoring of all servers. Ganglia is great for metrics, flickr can vouch for that one.

JangoSteve• 16 years ago

For all of my Rails apps, I use a combination of Munin (for trending and profiling over time), NewRelic (for daily and weekly profiling and optimization) and AreMySitesUp (for 15-min pinging).

Ask HN: What do you use to monitor your web application?

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