Overview
The following sections describe operational issues that should be anticipated prior to installing and running Urchin. Some of the information is required to operate Urchin successfully. Other items are important for getting the most out of Urchin depending on your particular needs once the software is installed. This document is an overview of the pertinent topics. Complete implementation of some items may require review of other appropriate detailed sections within the Document Center.
Basic Urchin Installation Considerations
- On Windows you must install while logged in as the Administrator.
- On UNIX-type systems you may install as any user, but if you do not install as the superuser, you will be restricted in what areas of the file system you may install.
- Urchin comes bundled with an Apache webserver binary for configuration and report delivery. Your systems administrators should be aware that this new web service will be running after Urchin is installed.
- Although the Urchin distribution itself is small, taking up only about 10 megabytes, you should install in a disk location that has plenty of room (e.g. several hundred megabytes at least) to allow for the growth of the Urchin databases over time. See the Performance and Management Issues section for additional considerations.
- If you are upgrading from Urchin 3, you will need to import your databases into Urchin 4 using the u3importer utility. There is no direct upgrade of Urchin 3 to Urchin 4 simply by running the Urchin 4 installer. See Upgrades in the Getting Started section of the Document Center.
Basic Urchin Processing Considerations
- Access to webserver logs - you must know the path to the log files for a given site, and you must have permission to access these files. If the logs are on a remote system, then you will also need an account name and password to use when retrieving the logs.
- Properly configured log format - although Urchin can process custom log formats, you will simplify the management requirements if you configure your webserver as appropriate to log in either Extended Combined Log Format (e.g. NCSA or Apache logs), or W3C Extended Log Format WITHOUT Process Accounting turned on (e.g. IIS logs). See the Advanced Configuration section for additonal considerations.
- The network address of a local DNS server - this is necessary to translate incoming network addresses in the logfiles into logical domains. See your network administrator if you are not sure about this information.
- Unique user account for Urchin processes - On UNIX-type systems it is desirable to enhance security by having Urchin programs run as a special user id that is used exclusively for Urchin and has only limited privileges. Setting up such an account will require that you have elevated or superuser privileges on the system in question.
Advanced Urchin Processing Considerations
- If you desire Unique Visitor tracking then you will have to
perform
the following basic steps:
- Install the UTM sensor code in the web pages on your site
- Activate cookie logging in the log format for your webserver
- Set the tracking methodology in the Urchin Profile for the website to be UTM
- If you choose not to use Unique Visitor tracking then you should consider what level of granularity you desire for visitor or session reporting, and select the appropriate alternative Visitor Tracking Method for each site. Besides UTM the choices are IP only, IP/User-Agent (the default), or Session ID.
Performance and Management Issues
- Log rotation - if you do not have some external mechanism for archiving or removing webserver logs after they have been processed by Urchin, you can configure Urchin to perform this task in the Advanced Settings for each Log Source.
- Retaining past Urchin databases for historical reporting - once the databases for a given month are created they are available from then on for historical analysis. Users should consider how far back they need to keep historical data so they can plan for purging unnecessary data to save disk space.
- Memory requirements - Urchin has configuration controls to limit the amount of RAM it utilizes when processing logs. The default is set to 20Mb, which may be too conservative for sites with logs greater than 10Mb in size. Plan to have sufficient system RAM so that you may up Urchin memory usage as needed and tune the software's memory settings for maximum processing performance.
- Location of Urchin data storage - utilizing the etc/urchin.conf file, Urchin can be configured so that the report databases are stored in a file system area outside the Urchin distribution. This allows you to allocate dedicated sufficient file system space for database growth where it's most convenient.
Remote Access and Integration Issues
- Using SSL for Urchin administration and reporting - the webserver that is bundled with Urchin is compiled with support for SSL. The configuration does not have SSL activated by default, however this can be turned on as desired by the user.
- Firewall configuration - if your network topology includes firewalls, proxy servers, and other elements that will be in between the Urchin processing server and users trying to view reports or systems that hold logs that need to be retrieved, then those devices will have to be configured so that they don't interfere with Urchin's remote access. This typically can be done without subverting the security that such a topology is intended to provide.