NAME
    Elasticsearch - The official client for Elasticsearch

VERSION
    version 0.74

SYNOPSIS
        use Elasticsearch;

    Connect to "localhost:9200":

        my $e = Elasticsearch->new();

    Round-robin between two nodes:

        my $e = Elasticsearch->new(
            nodes => [
                'search1:9200',
                'search2:9200'
            ]
        );

    Connect to cluster at "search1:9200", sniff all nodes and round-robin
    between them:

        my $e = Elasticsearch->new(
            nodes    => 'search1:9200',
            cxn_pool => 'Sniff'
        );

    Index a document:

        $e->index(
            index   => 'my_app',
            type    => 'blog_post',
            id      => 1,
            body    => {
                title   => 'Elasticsearch clients',
                content => 'Interesting content...',
                date    => '2013-09-24'
            }
        );

    Get the document:

        my $doc = $e->get(
            index   => 'my_app',
            type    => 'blog_post',
            id      => 1
        );

    Search:

        my $results = $e->search(
            index => 'my_app',
            body  => {
                query => {
                    match => { title => 'elasticsearch' }
                }
            }
        );

DESCRIPTION
    Elasticsearch is the official Perl client for Elasticsearch, supported
    by elasticsearch.com <http://www.elasticsearch.com>. Elasticsearch
    itself is a flexible and powerful open source, distributed real-time
    search and analytics engine for the cloud. You can read more about it on
    elasticsearch.org <http://www.elasticsearch.org>.

  Motivation
        *The greatest deception men suffer is from their own opinions.*

        Leonardo da Vinci

    All of us have opinions, especially when it comes to designing APIs.
    Unfortunately, the opinions of programmers seldom coincide. The
    intention of this client, and of the officially supported clients
    available for other languages, is to provide robust support for the full
    native Elasticsearch API with as few opinions as possible: you should be
    able to read the Elasticsearch reference documentation
    <http://www.elasticsearch.org/guide> and understand how to use this
    client, or any of the other official clients.

    Should you decide that you want to customize the API, then this client
    provides the basis for your code. It does the hard stuff for you,
    allowing you to build on top of it.

  Features
    This client provides:

    *   Full support for all Elasticsearch APIs

    *   HTTP backend (currently synchronous only - Any::Event support will
        be added later)

    *   Robust networking support which handles load balancing, failure
        detection and failover

    *   Good defaults

    *   Helper utilities for more complex operations, such as bulk indexing,
        scrolled searches and reindexing.

    *   Logging support via Log::Any

    *   Compatibility with the official clients for Python, Ruby, PHP and
        Javascript

    *   Easy extensibility

INSTALLING ELASTICSEARCH
    You can download the latest version of Elasticsearch from
    <http://www.elasticsearch.org/download>. See the installation
    instructions
    <http://www.elasticsearch.org/guide/reference/setup/installation/> for
    details. You will need to have a recent version of Java installed,
    preferably the Java v7 from Sun.

CREATING A NEW INSTANCE
    The "new()" method returns a new client which can be used to run
    requests against the Elasticsearch cluster.

        use Elasticsearch;
        my $e = Elasticsearch->new( %params );

    The most important arguments to "new()" are the following:

  "nodes"
    The "nodes" parameter tells the client which Elasticsearch nodes it
    should talk to. It can be a single node, multiples nodes or, if not
    specified, will default to "localhost:9200":

        # default: localhost:9200
        $e = Elasticsearch->new();

        # single
        $e = Elasticsearch->new( nodes => 'search_1:9200');

        # multiple
        $e = Elasticsearch->new(
            nodes => [
                'search_1:9200',
                'search_2:9200'
            ]
        );

    Each "node" can be a URL including a scheme, host, port, path and
    userinfo (for authentication). For instance, this would be a valid node:

        https://username:password@search.domain.com:443/prefix/path

    See "node" in Elasticsearch::Role::Cxn::HTTP for more on node
    specification.

  "cxn_pool"
    The CxnPool modules manage connections to nodes in the Elasticsearch
    cluster. They handle the load balancing between nodes and failover when
    nodes fail. Which "CxnPool" you should use depends on where your cluster
    is. There are three choices:

    *   "Static"

            $e = Elasticsearch->new(
                cxn_pool => 'Static'     # default
                nodes    => [
                    'search1.domain.com:9200',
                    'search2.domain.com:9200'
                ],
            );

        The Static connection pool, which is the default, should be used
        when you don't have direct access to the Elasticsearch cluster, eg
        when you are accessing the cluster through a proxy. See
        Elasticsearch::CxnPool::Static for more.

    *   "Sniff"

            $e = Elasticsearch->new(
                cxn_pool => 'Sniff',
                nodes    => [
                    'search1:9200',
                    'search2:9200'
                ],
            );

        The Sniff connection pool should be used when you do have direct
        access to the Elasticsearch cluster, eg when your web servers and
        Elasticsearch servers are on the same network. The nodes that you
        specify are used to *discover* the cluster, which is then *sniffed*
        to find the current list of live nodes that the cluster knows about.
        See Elasticsearch::CxnPool::Sniff.

    *   "Static::NoPing"

            $e = Elasticsearch->new(
                cxn_pool => 'Static::NoPing'
                nodes    => [
                    'proxy1.domain.com:80',
                    'proxy2.domain.com:80'
                ],
            );

        The Static::NoPing connection pool should be used when your access
        to a remote cluster is so limited that you cannot ping individual
        nodes with a "HEAD /" request.

        See Elasticsearch::CxnPool::Static::NoPing for more.

  "trace_to"
    For debugging purposes, it is useful to be able to dump the actual HTTP
    requests which are sent to the cluster, and the response that is
    received. This can be enabled with the "trace_to" parametere, as
    follows:

        # To STDERR
        $e = Elasticsearch->new(
            trace_to => 'Stderr'
        );

        # To a file
        $e = Elasticsearch->new(
            trace_to => ['File','/path/to/filename']
        );

    Logging is handled by Log::Any. See Elasticsearch::Logger::LogAny for
    more information.

  Other
    Other arguments are explained in the respective module docs.

RUNNING REQUESTS
    When you create a new instance of Elasticsearch, it returns a client
    object, which can be used for running requests.

        use Elasticsearch;
        my $e = Elasticsearch->new( %params );

        # create an index
        $e->indices->create( index => 'my_index' );

        # index a document
        $e->index(
            index   => 'my_index',
            type    => 'blog_post',
            id      => 1,
            body    => {
                title   => 'Elasticsearch clients',
                content => 'Interesting content...',
                date    => '2013-09-24'
            }
        );

    See Elasticsearch::Client::Direct for more details about the requests
    that can be run.

MODULES
    Each chunk of functionality is handled by a different module, which can
    be specified in the call to new() as shown in cxn_pool above. For
    instance, the following will use the Elasticsearch::CxnPool::Sniff
    module for the connection pool.

        $e = Elasticsearch->new(
            cxn_pool => 'Sniff'
        );

    Custom modules can be named with the appropriate prefix, eg
    "Elasticsearch::CxnPool::", or by prefixing the full class name with
    "+":

        $e = Elasticsearch->new(
            cxn_pool => '+My::Custom::CxnClass'
        );

    The modules that you can override are specfied with the following
    arguments to "new()":

  "client"
    The class to use for the client functionality, which provides methods
    that can be called to execute requests, such as "search()", "index()" or
    "delete()". The client parses the user's requests and passes them to the
    "transport" class to be executed. See :

    *   Elasticsearch::Client::Direct (default)

    *   Elasticsearch::Client::Compat (for migration from the old
        ElasticSearch module)

  "transport"
    The Transport class accepts a parsed request from the "client" class,
    fetches a "cxn" from its "cxn_pool" and tries to execute the request,
    retrying after failure where appropriate. See:

    *   Elasticsearch::Transport

  "cxn"
    The class which handles raw requests to Elasticsearch nodes. See:

    *   Elasticsearch::Cxn::LWP (default)

    *   Elasticsearch::Cxn::HTTPTiny

    *   Elasticsearch::Cxn::NetCurl

  "cxn_factory"
    The class which the "cxn_pool" uses to create new "cxn" objects. See:

    *   Elasticsearch::Cxn::Factory

  "cxn_pool" (2)
    The class to use for the connection pool functionality. It calls the
    "cxn_factory" class to create new "cxn" objects when appropriate. See:

    *   Elasticsearch::CxnPool::Static (default)

    *   Elasticsearch::CxnPool::Sniff

    *   Elasticsearch::CxnPool::Static::NoPing

  "logger"
    The class the use for logging events and tracing HTTP
    requests/responses. See:

    *   Elasticsearch::Logger::LogAny

  "serializer"
    The class to use for serializing request bodies and deserializing
    response bodies. See:

    *   Elasticsearch::Serializer::JSON

MIGRATING FROM ElasticSearch.pm
    See Elasticsearch::Compat, which allows you to run your old
    ElasticSearch code with the new Elasticsearch module.

    The Elasticseach API is pretty similar to the old ElasticSearch API, but
    there are a few differences. The most notable are:

  "hosts" vs "servers"
    When instantiating a new Elasticsearch instance, use "nodes" instead of
    "servers":

        $e = Elasticsearch->new(
            nodes => [ 'search1:9200', 'search2:9200' ]
        );

  "no_refresh"
    By default, the new client does not sniff the cluster to discover nodes.
    To enable sniffing, use:

        $e = Elasticsearch->new(
            cxn_pool => 'Sniff',
            nodes    => [ 'search1:9200', 'search2:9200' ]
        );

    To disable sniffing (the equivalent of setting "no_refresh" to "true"),
    do:

        $e = Elasticsearch->new(
            nodes    => [ 'search1:9200', 'search2:9200' ]
        );

  Request parameters
    In the old client, you could specify query string and body parameters at
    the same level, eg:

        $e->search(
            search_type => 'count',
            query       => {
                match_all => {}
            }
        );

    In the new client, body parameters should be passed in a "body" element:

        $e->search(
            search_type => 'count',
            body        => {
                query       => {
                    match_all => {}
                }
            }
        );

  "trace_calls"
    The new client uses Log::Any for event logging and request tracing. To
    trace requests/responses in "curl" format, do:

        # To STDERR
        $e = Elasticsearch->new (trace_to => 'Stderr');

        # To a file
        $e = Elasticsearch->new (trace_to => ['File','/path/to/file.log']);

  SearchBuilder
    The old API integrated ElasticSearch::SearchBuilder for an SQL::Abstract
    style of writing queries and filters in Elasticsearch. This integration
    does not exist in the new client, but will be added in a future module.

  Bulk methods and "scrolled_search()"
    Bulk indexing has changed a lot in the new client. The helper methods,
    eg "bulk_index()" and "reindex()" have been removed from the main
    client, and the "bulk()" method itself now simply returns the response
    from Elasticsearch. It doesn't interfere with processing at all.

    These helper methods have been replaced by the Elasticsearch::Bulk
    class. Similarly, "scrolled_search()" has been replaced by the
    Elasticsearch::Scroll.

TODO
    *   Async support

        Add async support using Promises for AnyEvent and perhaps Mojo.

    *   New frontend

        Add a new client with a similar less verbose interface to
        ElasticSearch and integration with ElasticSearch::SearchBuilder.

BUGS
    This is a stable API but this implemenation is new. Watch this space for
    new releases.

    If you have any suggestions for improvements, or find any bugs, please
    report them to
    <http://github.com/elasticsearch/elasticsearch-perl/issues>. I will be
    notified, and then you'll automatically be notified of progress on your
    bug as I make changes.

SUPPORT
    You can find documentation for this module with the perldoc command.

        perldoc Elasticsearch

    You can also look for information at:

    *   GitHub

        <http://github.com/elasticsearch/elasticsearch-perl>

    *   CPAN Ratings

        <http://cpanratings.perl.org/d/Elasticsearch>

    *   Search MetaCPAN

        <https://metacpan.org/module/Elasticsearch>

    *   IRC

        The #elasticsearch <irc://irc.freenode.net/elasticsearch> channel on
        "irc.freenode.net".

    *   Mailing list

        The main Elasticsearch mailing list
        <http://www.elasticsearch.org/community/forum/>.

TEST SUITE
    The full test suite requires a live Elasticsearch node to run, and
    should be run as :

        perl Makefile.PL
        ES=localhost:9200 make test

    TESTS RUN IN THIS WAY ARE DESTRUCTIVE! DO NOT RUN AGAINST A CLUSTER WITH
    DATA YOU WANT TO KEEP!

    You can change the Cxn class which is used by setting the "ES_CXN"
    environment variable:

        ES_CXN=HTTPTiny ES=localhost:9200 make test

AUTHOR
    Clinton Gormley <drtech@cpan.org>

COPYRIGHT AND LICENSE
    This software is Copyright (c) 2013 by Elasticsearch BV.

    This is free software, licensed under:

      The Apache License, Version 2.0, January 2004

