"HowTo" Posts


Slow Server? This is the Flow Chart You're Looking For

By Andre Bullet_white Posted in HowTo Bullet_white Comments Comments

Your high-powered server is suddenly running dog slow, and you need to remember the troubleshooting steps again. Bookmark this page for a ready reminder the next time you need to diagnose a slow server.

Get on "top" of it

Linux's top command provides a wealth of troubleshooting information, but you have to know what you're looking for. Reference this diagram as you go through the steps below:

top output

Read More →

 

Scout is Hiring! Come Build the Future of Monitoring as Developer #2

By Andre Bullet_white Posted in HowTo Bullet_white Comments Comments

We take pride in building a server monitoring product our customers love with a lean, flat team. We're looking to add the fourth human to our close-knit group.

So, what's special about being a Ruby dev @ Scout?

First, great people! Second, great tech: come build beautiful realtime monitoring visualizations in d3 and Ruby. There won't be an LDAP integration in sight, we promise. Third, you'll have a tremendous impact as developer #2.

About you

Please be comfortable with Ruby and a framework like Rails or Sinatra. You should have some Javascript chops. Experience with high-throughput, data-heavy apps will give you a leg up.

Beyond the technical chops, the single most important thing is your initiative. Will you dive into a problem unprompted? Point out problems and give suggestions on fixing it? Given a high-level goal, can you break it actionable chunks, ask for help when you need it, and see everything through to completion? We're a flat organization, and we won't micro-manage your work.

Benefits

Competitive salary, health care reimbursement, and unlimited vacation time.

Location

We'll consider great remote candidates, but we'd love for you to join us in Fort Collins, Colorado.

A few things about Fort Collins: best place to live (Money Magazine), ranked 3rd on the Best Bicycle Cities list, one of the Ten Best Vacation Cities for Beer Lovers, and 300 days of sunshine! Our office is located minutes from Old Town, the heart of Fort Collins.

How to apply

Email us at punch.the.clock@scoutapp.com. Resumes are fine, but a more personal email is better.

 

Understanding CPU Steal Time - when should you be worried?

By Derek Bullet_white Posted in HowTo Bullet_white Comments Comments

A big thanks to Eric Lindvall of Papertrail for adding steal time to Scout's CPU Usage Plugin and helping out on this blog post!

Netflix tracks CPU Steal Time closely. In fact, if steal time exceeds their chosen threshold, they shut down the virtual machine and restart on a different physical server.

If you deploy to a virtualized environment (for example, Amazon EC2), steal time is a metric you'll want to watch. If this number is high, performance can suffer significantly. What is steal time? What causes high steal time? When should you be worried (and what should you do)?

Read More →

 

Omnibus Tutorial: Package a standalone Ruby gem

By Derek Bullet_white Posted in HowTo Bullet_white Comments Comments

stack o pancakes

A couple of years ago I visited Argentina. I have trouble enough pronouncing my limited English vocabulary and I don't speak Spanish, but after a bit of time, it was pretty easy to order food, buy groceries, and use a taxi. However, occasional hangups that happen during my regular life in the states would throw me out of sorts in Spanish: a taxi driver trying to explain he doesn't have enough change would send me off the rails.

Ruby is my English when it comes to writing software, so when I hit hangups installing something Ruby-related, I can usually work my way out of them. Our monitoring agent at Scout is a Ruby gem, and while most of our customers already have Ruby installed, for those that don't a seemingly small hangup to me can be frustrating for them.

Now, thanks to Omnibus, there's an easy way to distribute your Ruby gems as standalone, full-stack program. This means folks without Ruby can have as smooth of an experience with your hip new gem as a hardened Rubyist.

Here's how I've built a full-stack installer for our scout Ruby Gem.

Read More →

 

RVM, Bundler and Cron in Production: Round 2

By Derek Bullet_white Posted in HowTo Bullet_white Comments Comments

Back in 2010, we suggested using /bin/bash -l -c to run scout via Cron when using RVM. However, this was a brute approach: /bin/bash -l -c tells bash to behave as a login, interactive process. However, as Daniel Szmulewicz elequently stated in the comments for the original blog post, "Cron jobs are by nature non-login, non-interactive processes".

Fast-forward to today: RVM usage is continuing in production, and to make things more complicated, Cron jobs often need to account for both RVM and Bundler. So, what's our preferred approach when running Ruby executables via Cron in an RVM, RVM+Bundler, or Bundler environment? A shell script.

Cron Shell Script: RVM + Bundler

Lets say we want to run a Ruby executable (scout [KEY]) via Cron with (1) Ruby 1.9.2 and (2) my Rails App's Gem bundle:

Make the shell script executable: chmod +x FILE.sh.

Add the Cron job:

* * * * * shell_script.sh

But that's a lot of typing...

It's tempting to use /bin/bash -l -c when you are busy/lazy. To get around this, the scout install [KEY] command will detect if you are using (1) RVM and/or (2) Bundler. If so, we generate the shell script for you and make it executable.

scout install BNrIneEBMwE8h6VlhO4Bw4WmOVSLmnygSFZEPCfi
=== Scout Installation Wizard ===

It looks like you've installed Scout under RVM and/or Bundler. 
We've generated a shell script for you.

Run `crontab -e`, pasting the line below into your Crontab file:

* * * * * /Users/dlite/.scout/scout_cron.sh

How do we detect RVM and Bundler? We've encapsulated it into an Environment class:

 

The nuts and bolts of our Ruby-based realtime charts solution

By Derek Bullet_white Posted in Development, HowTo Bullet_white Comments Comments

Scout’s realtime charts have been a big hit. Once you start using them for major deploys or performance incidents, going back to ten terminal windows running “top” feels like the dark ages.

Realtime was a lot of fun to implement and it’s been rock-solid so far. A big reason it was so much fun? We were able to implement all of it in Ruby (outside the Javascript used to handle websockets in the browser) and didn’t need to deploy any infrastructure .

So, how did we go about it?

Read More →

 

Older posts: 1 2 3 4 5 6