Server Density Beta Update #5 – No data alerts

We have just pushed out a relatively major update to our server monitoring application, Server Density.

This update will be one of the last of the beta testing period – we are still on track for the full launch later this month.

No data received alerts

The most important update for users is the new “No data received” alert. Once configured, you can receive an e-mail or SMS when Server Density has received no monitoring data from your server for x minutes. This is primarily to alert you if the agent crashes or there is a problem with external communications from your server to our systems.

When you add a new server, a “no data received” alert will automatically be configured to be sent by e-mail after 10 minutes. You will need to manually add the alert for existing servers, which can be done from the Alerts tab.

Since the first release, we have improved the stability of the agent to try and catch all possible crashes but there is still the possibility that the agent process might be terminated for an unknown reason, and this new alert allows you to be notified when that happens.

A side effect of this check is you could configure it as a “down” alert so you can be notified within 1 minute of your server stopping responding. Whilst this is a legitimate use, we advise against relying solely on this check for that kind of alerting because we do not monitor your server from multiple locations as is done by the likes of Pingdom and other up/down monitoring services.

Many bug fixes / enhancements

Since the beta #4 release at the beginning of April we have made quite a few bug fixes and enhancements. These include fixes to the timezone support, handling of special characters in user names and tweaked images and styling.

We have also been working on improving performance by reducing application memory usage and improving query times. These are very small modifications but do make a difference to the responsiveness of the application overall.

Behind the scenes

A lot of work has gone on behind the scenes to prepare the product for the commercial launch which is still planned, and on track, for this month. This includes billing and invoicing. We use an internal API to handle centralised billing so much of the development has been hooking that up to the Account tab which, although hidden for now, is ready to display your account balance, invoices and allow purchase of SMS credits.

A future weekend technical post will go into more detail about how our internal API works.

sd-agent

Although the agent is very lightweight, we are currently testing a new data collection mechanism in the agent to reduce the overhead even further. Currently, checks are done using system specific calls to commands like memstat and ps. This is being replaced with parsing of the /proc filesystem which is both standard across many platforms and has none of the additional memory and CPU requirements of running system commands.

If you have not updated your agent recently, beta update #5 may break compatibility with the agent you have installed. Check this post for details. If you have installed / updated the agent since 2nd April then you do not need to do anything.

If you have any feedback or questions about this update, please get in touch.