Configuring Scan Cache

This task allows you to configure file system scan cache. By default, the cache is enabled and is cleared after every scan. The cache is shared by different scan types. Disabling the cache impacts scan performance. The task is applicable only on computers where the scanner is installed.

To resolve issues with disk space, change the location of the cache folder to Fixlet Change Scanner Cache folder. To check the current scanner cache settings, activate the Scanner Information analysis.

Available configuration options

File system cache settings

There are two options available:

  1. Invalidate cache after 24 hours – cache is preserved after scan and can be used with next BigFix Inventory scan within 24 hours
  2. Empty cache after every scan – cache is removed at the end of the scan

10.0.8 Use experimental CIT Scanner Cache3

From version 10.0.8, Cache 3, a new mechanism for caching information has been introduced. CIT Scanner Cache3 is optimized for lower CPU and memory footprint compared to default Cache2. It is recommended to use Cache3 on computers that experience scanning problems.

Cache 3 features

  • Cache optimization is supported on Windows, Linux and AIX.
  • Use CIT Scanner Cache3 if supported.
  • Cache3 is not yet supported on shared disk. Cache2 is used for remote disk scan.
  • Cache3 does not support the CPU threshold setting through Initiate Software Scan fixlet. The threshold is not considered and the scan uses 1 core without self-limiting it’s use.
  • Status of Cache3 enablement can be checked through Scanner Information Analysis: Property: Cache Optimization: adjusted to report ENABLED when Cache3 in use and property Cache3 State: ENABLED / DISABLED. Enabled when cache3 is activated and CIT Scanner in version 9.2.26.0000 or higher.

Cache 3 limitations

Functionalities not yet supported:
  1. Wildcard values, such as (*) (?) for “includeDirectory” are not supported.
  2. $local, $remote and $all media types are not supported and are not considered. These parameters are considered as local.
  3. Short Windows file names are not supported.
  4. UTF-8 encoding in file names is not supported.
  5. Timeout setting is not supported.
  6. File checksums and attributes other than file size are not cached.
  7. Cache is not rebuilt when a scan configuration changes. For example, when the catalog or a list of exclude directories or extensionToCache values changes. Perform cache reset using wscanfs -reset for the cache to be rebuilt after subsequent scan.

Changes

10.0.8 The option to 'disable cache' is discontinued.

10.0.8 The option to 'optimize the scanner cache' is discontinued.

To set the scanner optimization, either upgrade the scanner using fixlet provided in BigFix Inventory version 10.0.8 or manually change the Computer Setting CIT_Scan_Provider to provider_cache2.

9.2.24 Optimize the scanner cache

Cache 2 was introduced in BigFix Inventory Scanner and from version  the option also optimizes remote shared file systems.
Important: Starting from application update 9.2.6, new installations have the optimization enabled. Scanner cache settings is not changed until version 10.0.8.

Storage of configuration of Cache

Handling of cache is controlled per endpoint using computer settings:

  • CIT_Empty_Cache_After_Scan - when set to true then cache is removed at the end of scan. Otherwise is kept.
  • CIT_Scan_Provider – overrides default in action for type of cache to be used. Recommended value: provider_cache2

To enable cache optimization without upgrading the Scanner on a particular computer, perform these steps:

  1. Log in to BigFix Console.
  2. Navigate to Computer Management > Computers and select the computer.
  3. Check the value of the CIT_Scan_Provider parameter.
    Result:
    • If the value is provider_cache, the optimization is not enabled.
    • If the value is provider_cache2, the optimization is enabled.
    • If the value is provider_cache3 [10.0.8 CIT Scanner 9.2.26], the optimization is enabled.

When you enable the scan optimization (cache2), the cache that is created during the software scan includes only files that are relevant for the types of software scans that you are running. The size of the cache is reduced.