Environments are becoming ever more heterogeneous with the integration of new equipment with legacy systems. As the complexity of the environment increases, so does the variety of the monitoring requirements. It may be necessary to not only monitor processes, but to monitor CPU and RAM usage on older systems, disk space on systems that generate large log files, and the availability of databases, all spread across a variety of platforms.

The company in our case study has recently updated their phone system to handle increased demand on their call-center services. The servers for the new system provide everything from voicemail to voice response to outbound calling for the collections department, and most of them are running Unix or Linux. This has become a critical application, but the current monitoring solution does not provide for Linux or Unix systems.

In addition to making sure processes are running, several of the Windows servers provide shared network storage for users. On the older file servers, disk space is constantly at a premium, and because these servers also have other functions such as print server or web server, it is important that the administrators be notified promptly if the free space reaches specified minimum levels. One of the Unix systems also writes large log files that need to be moved off the server when lack of free space reaches critical levels.

Due to previous compatibility issues with their last monitoring solution and increased work to maintain it, the company would prefer to avoid client-side software that needs to be run on each system they wish to monitor.

Servers Alive performs all it's checks without requiring software to be run on the client. Instead, it initiates connections to the servers. The highly configurable interface includes standard protocols such as HTTP, FTP, SSH, Telnet, and SMTP, among others for TCP. It is also able to check UDP services (particularly useful for Citrix servers), DNS queries, and Radius servers.

The pre-configured checks meet most common requirements, including the ability to check Microsoft SQL and Oracle databases, and there is an external check available for MySQL. Servers Alive also includes Netware, HTTP, and RTSP checks, in addition to Windows NT service, process, and resource monitoring.

The Protocols configuration allows the user to modify the existing entries and add new ones. The interface also allows the user to send specific information in packets and to check packets received from the target system against user entered information. This means that if the user is looking for a specific response from the monitored machine, they can send the packets necessary to elicit that response and check what is received in reply.

Through plugins, Servers Alive can provide additional monitoring for both Windows and Unix or Linux systems. While some functionality may be missing or limited in the base package, plugins are freely available for download on the Woodstone site. Some plugins are developed by Woodstone and others are created by Servers Alive users looking to add functionality for monitoring in their own environments.

Plugins available include the PS Com and DF Com components that allow the monitoring of processes and disk space on Linux or Unix systems. Also available are plugins that allow the checking of file sizes or existence, check the Windows event log for specific entries, and a Telnet scripting add on that will allow specific commands to be sent through Telnet. Users of Servers Alive can create custom checks, as well.

Another service the company provides to it's clients is hosting and maintaining their web sites. Often these sites allow the client's customers to service their own accounts, make payments, and update personal information. Currently they are only able to make sure the IIS servers are available. Recently they have added Apache servers, but are unable to monitor them.

Servers Alive can not only monitor both IIS and Apache web servers to make sure they are up and running, but it can also check page content by matching text or comparing time stamps. If your pages are displaying incorrectly or even in event of a security breach resulting in web site defacement, this can provide notification before there has been much public impact.

Overall, Servers Alive can provide monitoring and alert notification for Unix and Linux servers as well as Windows servers, becoming more important as the number Linux systems in formerly Windows-only environments increase. Plugins and customizable features allow great flexibility in what types of services and resources can be monitored, as well.