Resolving Problems Downloading New Forecast Data within HURREVAC
HURREVAC Tech Note 5 - updated 5/15/2012
Firewalls, HTTP Proxy settings, restrictive folders permissions, and local file caches are some common culprits when HURREVAC fails to update properly. This technical note describes the program's methods of updating and how to troubleshoot if you are having problems downloading new forecast data.
Update Methods - Automatic or Manual Polling
HURREVAC uses HTTP to download new forecast data from the Internet. All in-program data is drawn from http://data.hurrevac.com. Polling for new data occurs automatically beginning just a few seconds after program startup. You can set a polling interval of as often as every 5 minutes or as infrequent as every 3 hours. 10 minutes is the default selection on HURREVAC's Download tab of the Setup panel. You can also opt to turn off the autopolling and rely instead on the manual 'Update Now' button near the top of the program.
Autopolling in HURREVAC is not taxing to either your network bandwidth or computer's hard drive. The storm files, text advisories, and other live data downloaded through the program are all quite small....on the order of visiting a basic web page with a few small images. With the exception of the text advisories which are uniquely named, most files overwrite older versions of the same so that the Hurrevac2010 Application Data directory under your user profile will not grow very large (i.e. the tide file will always be called latest.tid).
If HURREVAC's download attempt generates an error message
If HURREVAC fails to complete a download session, either through automatic or manual polling, an error message will appear describing the problem as a download issue. Various error messages can follow throughout the program if the program was unsuccessful in retrieving all files from the server.
To troubleshoot, go through the following list to identify the cause of the problem:
- Check through your browser to see if you have Internet access. Specifically, can you reach the data.hurrevac.com web site? If you can't reach this web site, ask your IT administrator about possible network-wide blocks.
- Temporarily disable your computer's firewall and check to see if HURREVAC can download data. If it works, add a permissions entry to the firewall software allowing the program to go through.
- Check your browser's settings to see if HTTP Proxy is configured. If it is, copy the settings you see in the browser to the 'Connection Settings' tab of HURREVAC's Setup panel. Ask your IT administrator for help if you are unsure of the proxy server details.
- If a network-wide firewall is in place, ask the network administrator add exclusions for HURREVAC's main server (126.96.36.199), backup server (188.8.131.52), and SSL Certificate Host (geotrust.com).
- Check permissions on the Current User's Application Data folder. The user must have full permissions in this directory. See Tech Note 4 for more details.
- Perform a 'clean boot' as described by this Microsoft Article to see if some unknown third-party service is interfering with HURREVAC's connection.
If HURREVAC's downloads are error-free but don't reliably produce the latest forecast information
HURREVAC will continue to present stale forecast information if your network (or computer) is returning old, cached versions of certain files rather than retrieving up-to-date versions from data.hurrevac.com. This cache behavior can seem quite random...certain files can be outdated for hours or days while others continue to be refreshed. If caching is occurring, often times the main filesizes.txt polling file is involved. You can view its contents by using a web browser to visit http://data.hurrevac.com/filesizes.txt. The dates and times in this file are recorded in Eastern time and should closely match the product issuance times of the National Hurricane Center, Central Pacific Hurricane Center, and Joint Typhoon Warning Center.
Option 1 - Discontinuing the Caching Rule on Your Local Network
To resolve this issue you will need to identify, clear, and turn off the source of the cache for data.hurrevac.com...either on your computer, a proxy server within your local network, or a server further up the Internet relay (at the ISP, for instance). For ease of testing purposes, you will want to have HURREVAC/Hurrevac2010 version 1.0.485 or higher since this version added the capability of RIGHT-CLICKING on the Update Now button to force a fresh download of all the latest data files.
If the cache source is your computer, then you may be able to correct this yourself. Under your computer's Control Panel...Internet Options, press the Delete Files button to clear your local cache of Temporary Internet Files. Then click the Settings button in Temporary Internet files and select 'Every visit to the page' from the option for when to check for newer versions of stored pages. Right-click the Update Now button in Hurrevac2010 to see if the program is updated after clearing your local cache.
See your network administrators for assistance if you continue to get stale files in HURREVAC and ask that they make all files coming from data.hurrevac.com non-cacheable.
Option 2 - Enforcing No-Caching with HTTPS Setting
An alternate option for dealing with this caching problem has been added to Hurrevac2010 version 1.1.11. Switching from HTTP to encrypted (HTTPS) transmission within the Setup Panel should signal your network not to cache files.
Check the box for HTTPS and press the Save button to exit Setup. RIGHT-CLICK on the Update Now button to force a fresh download of all current forecast files. Regular polling should bring in the latest information thereafter.