AC-Yenta

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META.yml  view on Meta::CPAN

--- #YAML:1.0
name:               AC-Yenta
version:            1.1
abstract:           eventually-consistent distributed key/value data store. et al.
author:
    - AdCopy <http://www.adcopy.com>
license:            perl
distribution_type:  module
configure_requires:
    ExtUtils::MakeMaker:  0
requires:
    AC::DC:               0
    BerkeleyDB:           0
    Crypt::Rijndael:      0
    Digest::SHA:          0
    Google::ProtocolBuffers:  0
    JSON:                 0
    POSIX:                0
    Sys::Hostname:        0

lib/AC/Yenta.pm  view on Meta::CPAN

=head2 Kibitzing

Each yenta kibitzes (gossips) with the other yentas in the network
to exchange status information, distribute key-value data, and
detect and correct inconsistent data.

=head2 Eventual Consistency

Key-value data is versioned with timestamps. By default, newest wins.
Maps can be configured to keep and return multiple versions and client
code can use other conflict resolution mechanisms.

Lost, missing or otherwise inconsistent data is detected
by kibitzing merkle tree hash values.

=head2 Topological awareness

Yentas can take network topology into account when tranferring
data around to minimize long-distance transfers. You will need to
write a custom C<MySelf> class with a C<my_datacenter> function.

lib/AC/Yenta.pm  view on Meta::CPAN

    syslog local5

=item debug

enable debugging for a particular section

    debug map

=item map

configure a map (a collection of key-value data). you do not need
to configure the same set of maps on all servers. maps should be
configured similarly on all servers that they are on.

    map users {
	backend	    bdb
        dbfile      /home/acdata/users.ydb
        history     4
    }

=back

=head1 BUGS

lib/AC/Yenta/D.pm  view on Meta::CPAN

    return bless \$class, $class;
}

sub daemon {
    my $me    = shift;
    my $cfile = shift;
    my $opt   = shift;	# foreground, debugall, persistent_id, argv

    die "no config file specified\n" unless $cfile;

    # configure
    $AC::Yenta::CONF = AC::Yenta::Config->new(
        $cfile, onreload => sub {
            AC::Yenta::Store::configure();
        });


    initlog( 'yenta', (conf_value('syslog') || 'local5'), $opt->{debugall} );

    AC::Yenta::Debug->init( $opt->{debugall}, $AC::Yenta::CONF);
    daemonize(5, 'yentad', $opt->{argv}) unless $opt->{foreground};
    verbose("starting.");


    $SIG{CHLD} = $SIG{PIPE} = sub{};        				# ignore
    $SIG{INT}  = $SIG{TERM} = $SIG{QUIT} = \&AC::DC::IO::request_exit;  # abort

    # initialize subsystems
    my $port = $opt->{port} || conf_value('port');

    AC::Yenta::MySelf->init( $port, $opt->{persistent_id} );
    AC::Yenta::Store::configure();
    AC::Yenta::Status::init( $port );
    AC::Yenta::Monitor::init();
    AC::Yenta::NetMon::init();
    AC::DC::IO::TCP::Server->new( $port, 'AC::Yenta::Server' );
    verbose("server started on tcp/$port");


    # start "cronjobs"
    AC::DC::Sched->new(
        info	=> 'check config files',

lib/AC/Yenta/Status.pm  view on Meta::CPAN

    if( $DATA->{allpeer}{$id} ){
        # already known
        delete $DATA->{sceptical}{$id};
        return;
    }

    debug("rcvd update (sceptical) about $id from $io->{peerip}");

    # only accept updates from the server itself
    # no 3rd party updates. no misconfigured serevrs.
    problem("server misconfigured $id != $io->{peerip}")
      unless grep { inet_atoi($io->{peerip}) == $_->{ipv4}  } @{$up->{ip}};

    $up->{id} = $id;
    delete $up->{lastup};
    $DATA->{sceptical}{$id} = $up;
}

sub update {
    my $class = shift;
    my $id    = shift;	# -> server_id

lib/AC/Yenta/Store.pm  view on Meta::CPAN

use AC::Yenta::Store::AE;
use AC::Yenta::Store::Expire;
use strict;

our @EXPORT = qw(store_get store_put store_want store_get_merkle store_get_internal store_set_internal store_expire store_remove);

my %STORE;


# create maps from config
sub configure {

    my $maps = $AC::Yenta::CONF->{config}{map};

    my %remove = %STORE;
    for my $map (keys %{$maps}){
        debug("configuring map $map");

        my $conf = $maps->{$map};
        my $sharded = $conf->{sharded};
        my $c  = $sharded ? 'AC::Yenta::Store::Sharded' : 'AC::Yenta::Store::Map';