PrintUsedCIs(8)

Name

PrintUsedCIs - print the current set of allocated cache indecies for the Vesta-2 cache daemon

Synopsis

PrintUsedCIs [ -verbose ]

Description

Each cache entry stored by the Vesta-2 cache daemon VCache(1) has a cache index number (of "CI") which uniquely identifies it. When an entry is added to the cache, a new cache index is allocated for it. Weeding makes the cache indecies of deleted entreis available for re-allocation. This inspection utility will display the current set of allocated cache indecies. (This information is primarily of interest to maintainers who need to debug the cache daemon's behavior.)

By default, the program displays the full set of currently allocated CIs. If -verbose is specified, it prints more details about how the used CI set is stored. Specifically, when CIs are allocated or freed an entry recording this is added to a transaction log (to facilitate restoring the current state in the event of a server failure). Using -verbose will print the initial state before the transaction log, all the transaction log entries for cache index allocation/free operations, and the final set of used CIs.

Example

The following is an example of the output (without using -verbose):

>>>>>> Used CIs <<<<<<

    0-78151, 78463-78700, 78706-78817, 79287-79291, 100103-100104, 
    100343-100350, 100353, 100355-100367, 101704, 102209, 
    102225-102226 

  (78535 total)

Note that the size of the currently allocated CI set (printed at the end) corresponds to the "NUM ENTS" column in the output of VCacheMonitor(1).

Configuration Variables

PrintUsedCIs locates the allocated cache index transaction log by reading site-specific configuration information from a Vesta-2 configuration file.

The configuration file is divided into a number of sections, denoted in the file by [SectionName]. The variables used by the PrintCacheLog are in the section denoted by [CacheServer]. Here are the variables it uses and their meanings; the types of the variables are shown in parentheses:

MetaDataRoot (string)

The pathname of the directory in which the Vesta system's metadata is stored. If this variable is undefined, the current directory is used. If defined, this path should end in a slash (/) character. Other configuration variables are interpreted relative to this path.

MetaDataDir (string)

The directory (relative to the MetaDataRoot) in which the cache server's metadata is stored. This directory should end in a slash (/) character.

CILogDir (string)

The directory (relative to the MetaDataRoot/MetaDataDir) in which the cache server stores the cache index transaction log.

Files

$MetaDataRoot/$MetatDataDir/$CILogDir/*.ckp

Periodically (currently after the cache daemon finishes processing deletions), the complete set of currently allocated CIs is written out to a checkpoint file.

$MetaDataRoot/$MetatDataDir/$CILogDir/*.log

Where the transactions of cache indecies allocated and freed are stored.

See Also

VCache(1), VCacheImpl(7), VCacheMonitor(1)

Author

Kenneth C. Schalk <ken AT xorian DOT net>