HYPERCACHING

   

Virtual Machine  

Trail: PROIV Documentation > Administration > Managing Virtual Machine > Hypercaching

Caching mechanism improves performance and scalability by reducing the runtime execution time. In PROIV, the following PROISAM files are repeatedly accessed during execution. Thus caching the records improves the overall execution time by reducing the record’s access time. This enhances overall system performance.

Note: Currently Hypercaching feature is available only for UNIX platforms and is controlled by the environment variable RUNTIME_CACHE.

The version 7 caching model is referred as 'AUTO' and version 8 caching model is referred as 'FAST'. AUTO model retains the internal caches up-to-date against any modifications happening to pro-isam files, whereas the FAST model is 'cache and forget'. PROIV v8 FAST model does not support cache invalidation and is more suitable for read only boots. Similarly AUTO model is more suitable for developers.

PROIV Hypercaching (FAST) in version 8 increases the performance and scalability of the system by caching the file records in internally maintained caches. On first read the records are read from the file and placed in respective cache. The LRU (least recently used) algorithm is used to clear cache items when the cache gets full. You can set the cache size for each PROISAM file through environment variables in the PROIV Control Panel.

CACHE ENVIRONMENT VARIABLES

Following are the environment variables which define the runtime caching model. The runtime setting of one cache has no effect on the other cache.

You can set the size limit for each cache using size related cache size limit environment variables.

RUNTIME_CACHE

This environment variable determines the cache model  in effect. It sets the cache(s) initial value unless over-ridden explicitly. You can change the value of the RUNTIME_CACHE environment variable in PROIV Control Panel.

Set RUNTIME_CACHE to either of the following values:

OFF:   Caching environment is disabled for all file types unless it is overridden explicitly by individual cache environment variable.

AUTO: Caching environment is enabled and PROIV Version 7 caching model takes effect unless it is overridden explicitly by individual cache environment variable.

FAST:  Caching environment is enabled and PROIV Version 8 caching model takes effect unless it is overridden explicitly by individual cache environment variable.

The default value for RUNTIME_CACHE is AUTO.

 

GENFILE_RUNTIME_CACHE

This environment variable controls the runtime cache model for genfile records.

Set GENFILE_RUNTIME_CACHE to either of the following values:

OFF:   Caching environment is disabled for genfile cache.

AUTO: Use version 7 caching model for genfile cache.

FAST:  Use version 8 caching model for genfile cache.

The default value for GENFILE_RUNTIME_CACHE is AUTO unless RUNTIME_CACHE is set. The RUNTIME_CACHE value will be used in case GENFILE_RUNTIME_CACHE value is not set.

 

FUNCTION_RUNTIME_CACHE


This environment variable controls the runtime cache setting for functdef records.

Set FUNCTION_RUNTIME_CACHE to either of the following values:

OFF:   Caching environment is disabled for functdef cache.

AUTO: Use version 7 caching model for functdef cache.

FAST:  Use version 8 caching model for functdef cache.

The default value for FUNCTION_RUNTIME_CACHE is AUTO unless RUNTIME_CACHE is set. The RUNTIME_CACHE value will be used in case FUNCTION_RUNTIME_CACHE value is not set.

 

MSGF_RUNTIME_CACHE


This environment variable controls the runtime cache setting for msgf records.

Set MSGF_RUNTIME_CACHE to either of the following values:

OFF:   Caching environment is disabled for msgf cache.

AUTO: Use version 7 caching model for msgf cache.

FAST:  Use version 8 caching model for msgf cache.

The default value for MSGF_RUNTIME_CACHE is AUTO unless RUNTIME_CACHE is set. The RUNTIME_CACHE value will be used in case MSGF_RUNTIME_CACHE value is not set.

 

VARDEF_RUNTIME_CACHE

This environment variable controls the runtime cache setting for vardef records.

Set VARDEF_RUNTIME_CACHE to either of the following values:

OFF:   Caching environment is disabled for vardef cache.

AUTO: Use version 7 caching model for vardef cache.

FAST:  Use version 8 caching model for vardef cache.

The default value for VARDEF_RUNTIME_CACHE is AUTO unless RUNTIME_CACHE is set. The RUNTIME_CACHE value will be used in case VARDEF_RUNTIME_CACHE value is not set.

 

SECURITY_RUNTIME_CACHE

This environment variable controls the runtime cache setting for security records.

Set SECURITY_RUNTIME_CACHE to either of the following values:

OFF:   Caching environment is disabled for security cache.

AUTO: Use version 7 caching model for security cache.

FAST:  Use version 8 caching model for security cache.

The default value for SECURITY_RUNTIME_CACHE is AUTO unless RUNTIME_CACHE is set. The RUNTIME_CACHE value will be used in case SECURITY_RUNTIME_CACHE value is not set.

Note: The cache environment variable settings are effective for entire session. You must restart PROIV kernel for any change in the value of the runtime cache environment variables to take effect.  

 

Related Topics:

Configuring Cache Variables

Cache Statistics

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Topic ID: 700054