A note to myself on Caching

In Perl, a good module to use is CHI, a wrapper around specific data storage. This means there is one API to access the cache and the particular data store is hidden from the application.

• Local system

    use CHI;

    # Choose a driver
    
    my $cache = CHI->new( driver     => 'FastMmap',
                          root_dir   => '/path/to/cache',
                          cache_size => '1k'
    );

    my $cache = CHI->new( driver  => 'Memcached::libmemcached',
                          servers => [ "10.0.0.15:11211",

                                       "10.0.0.15:11212" ],
                          l1_cache => { driver   => 'FastMmap', 

                                        root_dir => '/path/to/cache' }
    );
    my $cache = CHI->new( driver   => 'BerkeleyDB',
                          root_dir => '/path/to/cache'
    );

    my $cache = CHI->new( driver => 'Memory',    global => 1 );
    my $cache = CHI->new( driver => 'RawMemory', global => 1 );

---


CHI::Driver::FastMmap          Shared memory inter-process cache via mmaped files
CHI::Driver::BerkeleyDB        Shared memory inter-process cache via Berkeley DB
                                                  environment using the Concurrent Data Store (CDS), making it
                                                  safe for multiple processes to read and write the cache without
                                                  explicit locking
CHI::Driver::Memory               In-process memory based cache
CHI::Driver::RawMemory        In-process memory based cache that stores references
                                                  directly instead of serializing/deep-copying)

• Distributed systems

    use CHI;

    my $cache = CHI->new(
        driver => 'Memcached',   # or 'Memcached::Fast', 

                                   or 'Memcached::libmemcached'
        namespace => 'products',
        servers => [ "10.0.0.15:11211", "10.0.0.15:11212", 

                     "/var/sock/memcached",
                     "10.0.0.17:11211", 

                     [ "10.0.0.17:11211", 3 ] 

                   ],
        debug => 0,
        compress_threshold => 10_000,
    );

Code examples taken from: CHI module on CPAN