The Server Status link

When you click on the Server Status link, it opens a form that gives you a nice overview of the main configuration parameters and information about the current state of GeoServer. A table view organizes the information. Other than being informative, this view lets you perform some maintenance operations.

From top to bottom, you will find several pieces of information:

• The Data directory link (first row) shows you the location of the configuration files for GeoServer. If you managed to change the default location, here, you can check that GeoServer is using the new folder you created:

• The Locks row shows you useful information for WFS-T editing. WFS-T stands for Transactional Web Feature Service; and, using this protocol, a client can edit data. To avoid data corruption, GeoServer locks the data on which a transaction is required until it ends. If the number shown is greater than one, then there are some transactions going on with your data.
• The Free Locks button lets you reset a hung editing session, removing any orphan processes to free locks that might have been abandoned.
• Connections show you the number of vector data store connections. Vector data stores are repositories configured for the persistence of features. You will create them in Chapter 4, Adding Your Data. Consider the following screenshot:

• Memory Usage shows you how much memory GeoServer is using. You can manually run the garbage collector by clicking on the Free memory button. This will destroy the Java objects marked for deletion.
• The next three rows show information about the version of the Java Virtual Machine (JVM) that the GeoServer is using. You configured it in Chapter 2, Getting Started with GeoServer, in the installation processes. You will also see a list of the fonts seen by the JVM and GeoServer. Fonts are useful to render labels for spatial features; we will explore this in Chapter 6, Styling Your Layers.
• The rows listed in the following screenshot show settings for the Java Advanced Imaging (JAI). These libraries are used for image rendering and allow for better performance when GeoServer manipulates raster data, as with Web Coverage Service (WCS) and Web Map Service (WMS) requests. We will install native JAI support in Chapter 11, Tuning GeoServer in a Production Environment:

• The Update Sequence link shows you how many times the server configuration has been updated. It is not that informative as of the time of writing this. The developers seem to have plans to use this to let you know that your configuration file has been updated externally from the application. Possibly from a REST call.
• GeoServer caches connections to stores, feature type definitions, external graphics, font definitions, and CRS definitions as well. Storing all this information increases the amount of memory used by the server. In a developing/debugging scenario, you can press the Clear button to force GeoServer to reopen the stores and reread the image and font information. This is shown in the following screenshot:

• The Configuration and catalog (last row) allows you to update the configuration without having to restart the service. GeoServer keeps configuration data in memory. If there is an external process updating the files containing the configuration's parameters, you can force GeoServer to reload settings from the XML files.