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AnyEvent-RipeRedis-Cluster-0.32
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NAME

AnyEvent::RipeRedis::Cluster - Non-blocking Redis Cluster client

SYNOPSIS

use AnyEvent;
use AnyEvent::RipeRedis::Cluster;

my $cluster = AnyEvent::RipeRedis::Cluster->new(
  startup_nodes => [
    { host => 'localhost', port => 7000 },
    { host => 'localhost', port => 7001 },
    { host => 'localhost', port => 7002 },
  ],
);

my $cv = AE::cv;

$cluster->set( 'foo', 'bar',
  sub {
    my $err = $_[1];

    if ( defined $err ) {
      warn $err->message . "\n";
      $cv->send;

      return;
    }

    $cluster->get( 'foo',
      sub {
        my $reply = shift;
        my $err   = shift;

        if ( defined $err ) {
          warn $err->message . "\n";
          $cv->send;

          return;
        }

        print "$reply\n";
        $cv->send;
      }
    );
  }
);

$cv->recv;

DESCRIPTION

AnyEvent::RipeRedis::Cluster is non-blocking Redis Cluster client built on top of the AnyEvent::RipeRedis.

Requires Redis 3.0 or higher, and any supported event loop.

For more information about Redis Cluster see here:

CONSTRUCTOR

new( %params )

my $cluster = AnyEvent::RipeRedis::Cluster->new(
  startup_nodes => [
    { host => 'localhost', port => 7000 },
    { host => 'localhost', port => 7001 },
    { host => 'localhost', port => 7002 },
  ],
  password           => 'yourpass',
  connection_timeout => 5,
  read_timeout       => 5,
  refresh_interval   => 5,
  lazy               => 1,
  reconnect_interval => 5,

  on_node_connect => sub {
    my $host = shift;
    my $port = shift;

    # handling...
  },

  on_node_disconnect => sub {
    my $host = shift;
    my $port = shift;

    # handling...
  },

  on_node_error => sub {
    my $err = shift;
    my $host = shift;
    my $port = shift;

    # error handling...
  },

  on_error => sub {
    my $err = shift;

    # error handling...
  },
);

COMMAND EXECUTION

<command>( [ @args ] [, ( $cb->( $reply, $err ) | \%cbs ) ] )

To execute the command you must call particular method with corresponding name. The reply to the command is passed to the callback in first argument. If any error occurred during the command execution, the error object is passed to the callback in second argument. The error object is the instance of the class AnyEvent::RipeRedis::Error.

Before the command execution, the client determines the pool of nodes, on which the command can be executed. The pool can contain the one or more nodes depending on the cluster and the client configurations, and the command type. The client will try to execute the command on random node from the pool and, if the command failed on selected node, the client will try to execute it on another random node.

The command callback is optional. If it is not specified and any error occurred, the on_error callback of the client is called.

The full list of the Redis commands can be found here: http://redis.io/commands.

$cluster->get( 'foo',
  sub {
    my $reply = shift;
    my $err   = shift;

    if ( defined $err ) {
      my $err_msg  = $err->message;
      my $err_code = $err->code;

      # error handling...

      return;
    }

    print "$reply\n";
  }
);

$cluster->lrange( 'list', 0, -1,
  sub {
    my $reply = shift;
    my $err   = shift;

    if ( defined $err ) {
      my $err_msg  = $err->message;
      my $err_code = $err->code;

      # error handling...

      return;
    }

    foreach my $value ( @{$reply}  ) {
      print "$value\n";
    }
  }
);

$cluster->incr( 'counter' );

If you want to track errors on particular nodes, you must specify on_node_error callback in command method.

$cluster->get( 'foo',
  { on_reply => sub {
      my $reply = shift;
      my $err   = shift;

      if ( defined $err ) {
        my $err_msg  = $err->message;
        my $err_code = $err->code;

        # error handling...

        return;
      }

      print "$reply\n";
    },

    on_node_error => sub {
      my $err  = shift;
      my $host = shift;
      my $port = shift;

      # error handling...
    }
  }
);

execute( $command [, @args ] [, ( $cb->( $reply, $err ) | \%cbs ) ] )

An alternative method to execute commands. In some cases it can be more convenient.

$cluster->execute( 'get', 'foo',
  sub {
    my $reply = shift;
    my $err   = shift;

    if ( defined $err ) {
      my $err_msg  = $err->message;
      my $err_code = $err->code;

      # error handling...

      return;
    }

    print "$reply\n";
  }
);

TRANSACTIONS

To perform the transaction you must get the master node by the key using nodes method and then execute all commands on this node. Nodes must be discovered first.

$node = $cluster->nodes('foo');

$node->multi;
$node->set( '{foo}bar', "some\r\nstring" );
$node->set( '{foo}car', 42 );
$node->exec(
  sub {
    my $reply = shift;
    my $err   = shift;

    if ( defined $err ) {
      # error handling...

      return;
    }

    # reply handling...
  }
);

The detailed information about the Redis transactions can be found in documentation on AnyEvent::RipeRedis and here: http://redis.io/topics/transactions.

ERROR CODES

Every error object, passed to callback, contain error code, which can be used for programmatic handling of errors. AnyEvent::RipeRedis::Cluster provides constants for error codes. They can be imported and used in expressions.

use AnyEvent::RipeRedis::Cluster qw( :err_codes );

Full list of error codes see in documentation on AnyEvent::RipeRedis.

DISCONNECTION

When the connection to the cluster is no longer needed you can close it in two ways: call the method disconnect() or just "forget" any references to an AnyEvent::RipeRedis::Cluster object, but in this case the client object is destroyed without calling any callbacks, including the on_disconnect callback, to avoid an unexpected behavior.

disconnect()

The method for disconnection. All uncompleted operations will be aborted.

OTHER METHODS

nodes( [ $key ] [, $allow_slaves ] )

Gets particular nodes of the cluster. Nodes must be discovered first. In scalar context method returns the first node from the list.

Getting all master nodes of the cluster:

my @master_nodes = $cluster->nodes;

Getting all nodes of the cluster, including slave nodes:

my @nodes = $cluster->nodes( undef, 1 );

Getting master node by the key:

my $master_node = $cluster->nodes('foo');

Getting nodes by the key, including slave nodes:

my @nodes = $cluster->nodes( 'foo', 1 );

refresh_interval( [ $fractional_seconds ] )

Gets or sets the refresh_interval of the client. The undef value resets the refresh_interval to default value.

on_error( [ $callback ] )

Gets or sets the on_error callback.

SERVICE FUNCTIONS

Service functions provided by AnyEvent::RipeRedis::Cluster can be imported.

use AnyEvent::RipeRedis::Cluster qw( crc16 hash_slot );

crc16( $data )

Compute CRC16 for the specified data as defined in Redis Cluster specification.

hash_slot( $key );

Returns slot number by the key.

SEE ALSO

AnyEvent::RipeRedis

AUTHOR

Eugene Ponizovsky, ponizovsky@gmail.com

Sponsored by SMS Online, dev.opensource@sms-online.com

COPYRIGHT AND LICENSE

Copyright (c) 2016-2017, Eugene Ponizovsky, SMS Online. All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.