/ 
Kafka-0.800_3
River stage one • 2 direct dependents • 2 total dependents
/ Kafka::IO

NAME

Kafka::IO - interface to network communication with the Apache Kafka server.

VERSION

This documentation refers to Kafka::IO version 0.800_3 .

SYNOPSIS

use 5.010;
use strict;
use warnings;

use Kafka::IO;

my $io = Kafka::IO->new( host => 'localhost' );

# Closes and cleans up
$io->close;

DESCRIPTION

This module is not intended to be used by end user.

In order to achieve better performance, methods of this module do not perform arguments validation.

The main features of the Kafka::IO class are:

  • Provides an object oriented API for communication with Kafka

  • This class allows you to create Kafka 0.8 clients that do not use ZooKeeper.

CONSTRUCTOR

new

Establishes TCP connection to given host and port, creates and returns Kafka::IO IO object.

An error will cause the program to return Kafka::IO object without halt.

You can use the methods of the Kafka::IO class - "last_errorcode" and "last_error" for getting the information about the error.

new() takes arguments in key-value pairs. The following arguments are currently recognized:

host => $host

$host is an Apache Kafka host to connect to. It can be a hostname or the IP-address in the "xx.xx.xx.xx" form.

port => $port

Optional, default = $KAFKA_SERVER_PORT.

$port is integer attribute denoting the port number of to access Apache Kafka.

$KAFKA_SERVER_PORT is the default Apache Kafka server port that can be imported from the Kafka module.

timeout => $timeout

Optional, default = $REQUEST_TIMEOUT.

$timeout specifies how long we wait for remote server to respond before the IO object disconnects and throws internal exception. The $timeout is specified in seconds (could be any integer or floating-point type) and supported by gethostbyname, connect, blocking receive and send calls.

$REQUEST_TIMEOUT is the default timeout that can be imported from the Kafka module.

METHODS

The following methods are provided by Kafka::IO class:

send( $message )

Sends a $message to Kafka.

The argument must be a bytes string.

Returns the number of characters sent. In case of error, returns undefined value.

receive( $length )

Receives a message up to $length size from Kafka.

Returns a reference to the received message. Returns undef in case of error.

$length argument must be a positive number.

close

Closes connection to Kafka server.

is_alive

The method verifies whether we are connected to Kafka server.

last_errorcode

Returns code of the last error.

last_error

Returns description of the last error.

DIAGNOSTICS

Use "last_errorcode" and "last_error" to get last error code & description.

Invalid argument

Invalid arguments were passed to a method.

Can't send

Message can't be sent on a Kafka::IO object socket.

Can't recv

Message can't be received.

Can't bind

TCP connection can't be established on given host and port.

SEE ALSO

The basic operation of the Kafka package modules:

Kafka - constants and messages used by the Kafka package modules.

Kafka::Connection - interface to connect to a Kafka cluster.

Kafka::Producer - interface for producing client.

Kafka::Consumer - interface for consuming client.

Kafka::Message - interface to access Kafka message properties.

Kafka::Int64 - functions to work with 64 bit elements of the protocol on 32 bit systems.

Kafka::Protocol - functions to process messages in the Apache Kafka's Protocol.

Kafka::IO - low level interface for communication with Kafka server.

Kafka::Internals - Internal constants and functions used by several package modules.

A wealth of detail about the Apache Kafka and the Kafka Protocol:

Main page at http://kafka.apache.org/

Kafka Protocol at https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol

AUTHOR

Sergey Gladkov, <sgladkov@trackingsoft.com>

CONTRIBUTORS

Alexander Solovey

Jeremy Jordan

Vlad Marchenko

COPYRIGHT AND LICENSE

Copyright (C) 2012-2013 by TrackingSoft LLC.

This package is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic at http://dev.perl.org/licenses/artistic.html.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.