Monitoring web servers don’t always follow RFCs

Posted on February 25th, 2011

Today a customer contacted me saying Overseer Network Monitoring Software gave this error when trying to monitor an RFID Reader device:

The server committed a protocol violation. Section=ResponseHeader Detail=CR must be followed by LF

As you can see, the error message is pretty clear that the server is violating RFC standards that state a carriage return(CR) must be followed by a line feed(LF). These RFCs have been around for a long time, but this is not the first time I’ve experienced firmware developers’ HTTP implementation falling short of RFC standards. I’m not a firmware developer, so there may be some good reasons for this– but at the same time, my customers need to be able to monitor any website, standards-compliant or not.

Therefore, I was able to find a work-around to let Overseer monitor a website when it experienced this sort of error. This is available in Overseer Network Monitor 4.1.24.

Overseer Released

Posted on February 25th, 2011

Today I released Overseer Network Monitor 4.1.24. This version includes a fix minor under-the-hood fixes, as well as a work-around for a customer who experience a problem monitoring web servers that are not RFC compliant.  This is a small release, but this was a critical feature for this customer to configure his network monitoring strategy.  If you experience any problems with Overseer, please let us know using the support link above so we can do our best to find a solution.  Thanks.

SQL Express Database Size Limit Notification

Posted on February 21st, 2011

Recently a customer needed to monitor MSSQL 2008 R2 Express database sizes and be notified when the size grew too large. It is quite easy to monitor SQL Express database size with Overseer Network Monitor’s Database monitoring capabilities.

As you may know, SQL Express 2008R2 is limited to 10GB databases. Older versions, such as SQL Express 2005 and 2008(R1) were limited to only 4GB. This customer needed to be notified when certain databases hit 80% of their allowed size, so they could run an archival process to keep the database size under the database size limit for SQL 2008 Express R2. To do this, we setup a DB Query resource like this for each database that needed monitoring:

We used this SQL query:

SELECT  (SUM(used_pages)*8192)/1024 FROM sys.allocation_units

This gets the size of the data+indexes in the current MSSQL Database. We then setup a simple scalar result evaluator to notify if this value exceeded 8,388,608(8GB). Now, whenever the database size grows large, the customer will receive Emails letting him know to run his archival process.

Overseer 4.1 upgrades are FREE!

Posted on February 19th, 2011

We’ve had a few people contact us asking if they have to pay to upgrade to 4.1. Just to clarify, all minor version upgrades of Overseer are free. That means 4.0.x to 4.1.x is a free upgrade. We charge for major version upgrades only(3.x->4.x). We offer special prices for 3.0 users upgrading to 4.x, and will do that someday when 5.0 is released(note that 5.0 is not currently under development– all new development is currently going into 4.x).

Overseer Released

Posted on February 15th, 2011

When we added support for the DB Query resource type in May last year, we only provided support for ODBC data sources. This was discouraging for some customers that rely on Windows authentication for MSSQL databases.

In 4.1.22, I’ve added native MSSQL support for the Database/SQL Monitoring, and included support for Windows Authentication in addition to native SQL Server authentication!

Overseer Released

Posted on February 12th, 2011

This version of Overseer Network Monitor fixes some performance problems that some people have experienced.

After some in-depth diagnosis with extremely slow computers and high resource loads, we’ve been able to re-create the issue. The problem stems from a stability fix made in May of last year.

This time, I was able to find a better fix for the problem that maintains full speed of the SQLite database system when the computer is under heavy load, and doesn’t sacrifice Overseer stability.

Overseer Released

Posted on February 5th, 2011

Sensible Software proudly announces Overseer 4.1!

This version has some big changes, so it deserved a minor version number change. As of 4.1, the version#’s will also be sequential and shorter– instead of 4.0.xxxxx, the version numbers will only be 4.1.xx, and may grow to before going to 4.2. The old version number had the date of the build in it, but we eventually found this wasn’t worthwhile to include, as it made it harder for people to write down the version# or know which one was older/newer due to the complex numbering scheme.

As for changes you’ll see in 4.1, we’ve introduced the Resource Discover Wizard! This is a very useful tool that enables you to discover resources on your network and create dozens, hundreds, or even thousands of resources in just minutes. Obviously you’ll want to be selective as to which things you select while using the wizard, but this should let you setup Overseer to monitor your network resources in minutes versus the many hours that would be required to setup monitoring for a large network otherwise.

For first time users, we’ve added the ‘First Run Wizard’. This wizard guides the user through setting up the basics, and then prompts them to run the resource discovery wizard, text file import wizard, Overseer 3.x import wizard, or to manually enter their own resources. This should make initial setup of Overseer quick and painless for all users.

Lastly, this version adds multi-selection support for pausing/unpausing and deleting resources. This is very useful if you’d like to easily enable/disable monitoring for multiple resources at once, or simply want to delete multiple resources from Overseer.

Resource Discovery Wizard

Posted on February 5th, 2011

The resource discovery wizard allows you to discover resources on your network so you don’t have to manually enter all your resources into Overseer. This wizard does require your computers to be a member of a Windows domain/active directory. It also requires a domain admin password to be used to setup the resources. This is generally the architecture most Overseer customers already use, so this shouldn’t be a significant limiting factor for most.

To run the resource discovery wizard, simply select the option under Tools, and follow the instructions:

First, you must specify a domain admin account for discovery to work reliably. You can then select the different resource types you want selected. Click the ‘Options’ button to specify resource-type-specific options.

Next, you can specify the Organizational Units(OU’s) in your domain that you’d like to discover for. This can help limit the scope of your discovery to just servers, just user’s workstations, etc. If you don’t have OU’s setup, you may see just “<<Unassigned Computers>>”– which includes all domain computers not otherwise assigned to an OU.

Next, you simply wait for discovery to complete. Overseer may take a while to connect to all computers and discover all their resources. If you have computers that are powered down in OU’s you’ve decided to discover, this may take even longer. Fortunately, Overseer discovers resources on multiple computers at once during this process.

On the next screen, pick the resources you’d like Overseer to monitor. By default, Overseer will check all the services that are in running state, all event logs, all disks, and all ping resources. This may be overkill for a good monitoring strategy– so you may want to go through and uncheck some services, if you know which ones do not need monitoring.

Next, specify the resource group, schedule, notification group, and custom text. If you’re not sure, the defaults will probably work.

Lastly, you simply let Overseer create your resources. Once that’s done, click ‘Finish’ and you should have many resources configured for you in Overseer.