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Older baseball players typically have plenty of power and discipline but are slow runners with lower batting averages. It’s kind of obvious: as we get older, we get bigger and more patient, but we also get slower. This characteristic even has a name, described as (you guessed it): old player skills.
Bill James, a famous baseball historian, studied these players and found that younger players that start with these skills fade away faster than than their peers. The players that have long careers are often those that have speed when they’re young and are able to adapt as the gifts of youth fade.
What does this have to do with small, self-funded, developer-run businesses like us?
James Gray, lead developer of the Scout Agent, takes a stab at the eternal question “What makes a great developer?” in the latest RailsCoach Podcast Episode.
Besides talking about Scout’s blended open-source approach to monitoring, James also talks about The Pomodoro Technique (a time management process), his time at the helm of the RubyQuiz, NoSQL, and other topics.
On Thursday, January 21st at 1pm Central I’ll be leading a webinar with Rackspace where I’ll show how Scout makes monitoring your cloud enviroment a snap. Using Scout, I’ll show how to:
monitor cloud servers automatically when they boot
update monitoring on your entire cluster in one click
In other words, you’ll learn how to get the day off the next time your monitoring infrastructure needs to be updated.
If you’re looking at deploying more of your infrastructure to the cloud and are curious about monitoring solutions this webinar is for you.
How much memory is really available on your Linux box? Don't use /proc/meminfo to find out, use free -m instead. You may have more memory available than you thought.
Here's an example. /proc/meminfo says about 330MB is free:
You'll see the "buffers" and "cached" columns, which tell you about the amount of memory that the kernel is using for filesystem buffers, etc.
This sort of cached data will be freed by the kernel when an application tries to allocate more than what is "free", which is why the "-/+ buffers/cache" line is really the important line to pay attention to when you're checking out the free memory on a system.
So in this example, 708MB is how much memory is technically available for allocation should an application need it. The "buffers" (86MB) and "cached" (288MB) will be released by the kernal if they are needed.
Just provide the paths to your Sphinx log files and Sam’s plugin reports the following data:
Queries per-minute
Average query time
Average time per rebuild
Index rebuilds
Average results returned
Like with any Scout plugin, you can plot metrics from the Sphinx Monitoring Plugin against other metrics. For example, the chart below shows the relationship between the Sphinx query rate and the server load:
With the fifth release of the Scout Agent we introduced server downtime monitoring to all of our plans. You may already use a website monitoring service like Pingdom for alerts when your website goes down. What’s the difference between website and server monitoring? Can one replace the other?
12/23 - UPDATE - Scout Agent v5 has exited the BETA phase. If you're already using Scout, upgrade instructions appear when viewing a server at scoutapp.com.
We’ve prepared a BETA release of the Scout Agent that monitors server downtime, supports SMS notifications, and makes creating your own plugins easier. We and a group of beta accounts been running it internally for some time, and now we invite you to try it out.
Get the New Agent
1) Install the Scout agent gem version 5.0.2:
sudo gem install scout
2) Change your crontab entry for Scout so it runs every minute, which is just * * * * * on Linux. Your current setup is */3, */10, or similar.
Take Advantage of New Features
Server Down Notifications
The new Agent pings Scout every minute. If Scout isn’t contacted for a 5 minute period, you can choose to receive a notification via email and/or SMS. Ensure you are receiving downtime notifications in the new ‘notifications’ section of Scout:
Note that only Ultimate Accounts have access to the SMS server down notifications.
Dual-tier SMS Alerts (Ultimate Accounts only)
When things go really wrong it’s important you find out quickly. Using Scout’s triggers, you can now specify a separate threshold for SMS alerts. For example, send an email alert if disk capacity is over 70% and an SMS alert if disk capacity is over 90%). Here’s how:
1) Enter your SMS info in the new "notifications" section of Scout:
2) Edit/create a trigger. You’ll see a new option for the SMS threshold:
When the entered threshold is crossed, you’ll receive an SMS alert. SMS alerts are currently available only on Ultimate accounts.
Easier Plugin Creation and Editing
Quicker configuration and setup: because the new Agent pings us every minute, it is much more responsive to changes you make in configurations on Scoutapp.com. Any changes you make will be picked up within 60 seconds by the new Agent, regardless of your plan level.
Easier editing of any plugin code from the Scout website: paste your plugin code directly onto Scoutapp.com. Quickly develop your custom plugins, and email us for inclusion in the plugin directory.
Explicit Checkin Times
When you upgrade to the new Agent, you'll see the "Server Contact" box on your server homepage, providing visual confirmation of most recent and next checkin times:
Summary
Get your new Agent here:
sudo gem install
We’d love your feedback on the new Agent and functionality. Leave your comment here or send an email with with any comments.
Our co-author today is Jesse Newland, CTO of RailsMachine. Jesse keeps RailsMachine customers up and running and troubleshoots their toughest problems. We’re pleased to have him share some of his expertise on Phusion Passenger tuning.
Say your Rails application is running in production and it’s getting good traffic. Performance isn’t as good you would like. You’ve already determined that your database is not the bottleneck. What’s your next move?
There is a good chance that Passenger’s PassengerMaxPoolSize needs to be adjusted. PassengerMaxPoolSize specifies how many instances of your application Passenger will spin up to service incoming requests. If you were running Mongrels back in the day, PassengerMaxPoolSize is equivalent to the number of mongrels you configured for your app. The value of PassengerMaxPoolSize has a major bearing on your application’s performance.
In less than two months, we’ve seen strong adoption of Scout’s simple cloud monitoring functionality. 1 of every 5 hosts monitored by Scout is in the cloud.
With more movement to the cloud, we’re happy to announce a new partnership with Rackspace Cloud Computing. Rackspace has an easy-to-use interface for provisioning servers backed by the fanatical support they are known for. Setting up monitoring on a Rackspace Cloud Server is trivial – install our Ruby gem and add a Cron entry.
When you get started with Scout, we try to setup sensible default triggers for events you may need to investigate on your servers.
For example, Scout generates an alert if your disk usage exceeds 85% or CPU Load over the last minute exceeds 3.
However, every server and application is different. For example, a CPU load of 3 is fine on some servers but a problem on others. We’ve made it easier to tune Scout for your setup if Scout is sending too many alerts.
Derek
Our co-author today is 
