CHI::Stats(3pm) User Contributed Perl Documentation CHI::Stats(3pm)
NAME
CHI::Stats - Record and report per-namespace cache statistics
VERSION
version 0.54
SYNOPSIS
# Turn on statistics collection
CHI->stats->enable();
# Perform cache operations
# Flush statistics to logs
CHI->stats->flush();
...
# Parse logged statistics
my $results = CHI->stats->parse_stats_logs($file1, ...);
DESCRIPTION
CHI can record statistics, such as number of hits, misses and sets, on a per-namespace basis and log the results to your Log::Any logger.
You can then parse the logs to get a combined summary.
A single CHI::Stats object is maintained for each CHI root class, and tallies statistics over any number of CHI::Driver objects.
Statistics are reported when you call the "flush" method. You can choose to do this once at process end, or on a periodic basis.
STATISTICS
The following statistics are tracked:
o absent_misses - Number of gets that failed due to item not being in the cache
o compute_time_ms - Total time spent computing missed results in compute, in ms (divide by number of computes to get average). i.e. the
amount of time spent in the code reference passed as the third argument to compute().
o computes - Number of compute calls
o expired_misses - Number of gets that failed due to item expiring
o get_errors - Number of caught runtime errors during gets
o get_time_ms - Total time spent in get operation, in ms (divide by number of gets to get average)
o hits - Number of gets that succeeded
o set_key_size - Number of bytes in set keys (divide by number of sets to get average)
o set_value_size - Number of bytes in set values (divide by number of sets to get average)
o set_time_ms - Total time spent in set operation, in ms (divide by number of sets to get average)
o sets - Number of sets
o set_errors - Number of caught runtime errors during sets
METHODS
enable
disable
enabled
Enable, disable, and query the current enabled status.
When stats are enabled, each new cache object will collect statistics. Enabling and disabling does not affect existing cache objects.
e.g.
my $cache1 = CHI->new(...);
CHI->stats->enable();
# $cache1 will not collect statistics
my $cache2 = CHI->new(...);
CHI->stats->disable();
# $cache2 will continue to collect statistics
flush
Log all statistics to Log::Any (at Info level in the CHI::Stats category), then clear statistics from memory. There is one log message
for each distinct triplet of root class, cache label, and namespace. Each log message contains the string "CHI stats:" followed by a
JSON encoded hash of statistics. e.g.
CHI stats: {"absent_misses":1,"label":"File","end_time":1338410398,"get_time_ms":5,
"namespace":"Foo","root_class":"CHI","set_key_size":6,"set_time_ms":23,
"set_value_size":20,"sets":1,"start_time":1338409391}
parse_stats_logs (log1, log2, ...)
Parses logs output by "CHI::Stats" and returns a listref of stats totals by root class, cache label, and namespace. e.g.
[
{
root_class => 'CHI',
label => 'File',
namespace => 'Foo',
absent_misses => 100,
expired_misses => 200,
...
},
{
root_class => 'CHI',
label => 'File',
namespace => 'Bar',
...
},
]
Lines with the same root class, cache label, and namespace are summed together.
Non-stats lines are ignored. The parser will ignore anything on the line before the "CHI stats:" string, e.g. a timestamp.
Each parameter to this method may be a filename or a reference to an open filehandle.
SEE ALSO
CHI
AUTHOR
Jonathan Swartz <swartz@pobox.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2011 by Jonathan Swartz.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
perl v5.14.2 2012-05-30 CHI::Stats(3pm)