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Automatically clearing WRS/URL cache in InterScan Web Security Virtual Appliance

    • Updated:
    • 5 Nov 2018
    • Product/Version:
    • InterScan Web Security Virtual Appliance 6.5
    • Platform:
    • N/A N/A
Summary

The WRS/URL cache keeps the frequently accessed URLs in cache for quick retrieval; building the local WRS/URL cache with this database information reduces the overhead on InterScan Web Security Virtual Appliance (IWSVA) and improves performance.

It is recommended to clear the cache only if a new URL query is necessary or if the cache size is affecting performance. This can be done via web console by navigating to HTTP > Configuration > WRS/URL Cache. However, it is also possible to schedule or automate the WRS/URL cache clearing function on a regular basis using the procedure in this article.

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There are two (2) options to clear the cache. Do any of the following:

Option A. Create a cron job

You can set up a cron job to clear the URL filtering cache on a regular basis. The script for clearing the URL filtering cache is the following:

/etc/iscan/clearURLCache.sh /etc/iscan/tmufe

 
Running this script will restart the HTTP daemon, which is the main scanning service.
This will interrupt internet access for the users.

To set up a cron job, add a line to the crontab file for the user iscan:

  1. Log on to IWSVA either directly or with SSH as "root".
  2. Open the crontab file for the user iscan:

    crontab -e -u iscan

  3. Add a line to the crontab file. The crontab editor works analogue to vim. Refer to this article for further instructions.
    1. Assuming that you would like to clear the cache once a day at 2:15 AM, you need to add the following line at the bottom of the file:

      15 2 * * * /etc/iscan/clearURLCache.sh /etc/iscan/tmufe > /dev/null 2>&1

    2. Save the changes and close the file.
  4. Run the command below to check that the job was added:

    crontab -l -u iscan

Option B. Set the lifetime for the cache entries

You can define the lifetime for the entries in the URL filtering cache on IWSVA. By default, IWSVA does not limit the lifetime of an entry. Instead, the lifetime of an entry is set by the rating server and may vary for different URLs.

To manually set the lifetime for the entries in URL filtering cache:

  1. Log on to IWSVA either directly or with SSH as "root".
  2. Open and edit the file /etc/iscan/urlfcIFX.ini as described in this article.
    1. Change the value of the parameter "SetCacheLife" from "no" to "yes".
    2. Edit the value of the parameter "CacheLife". The value is in minutes.
    3. Save the changes and close the file.
  3. Restart the HTTP daemon for the changes to take effect.
     
    Restarting the HTTP daemon will cause service interruption so schedule appropriately.

    /etc/iscan/S99ISproxy stop && /etc/iscan/S99ISproxy start

Premium
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Rating:
Category:
Configure
Solution Id:
1121463
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