NAME
Catmandu::Store::ElasticSearch - A searchable store backed by Elasticsearch
SYNOPSIS
# From the command line
# Import data into ElasticSearch
$ catmandu import JSON to ElasticSearch --index-name 'catmandu' < data.json
# Export data from ElasticSearch
$ catmandu export ElasticSearch --index-name 'catmandu' to JSON > data.json
# Export only one record
$ catmandu export ElasticSearch --index-name 'catmandu' --id 1234
# Export using an ElasticSearch query
$ catmandu export ElasticSearch --index-name 'catmandu' --query "name:Recruitment OR name:college"
# Export using a CQL query (needs a CQL mapping)
$ catmandu export ElasticSearch --index-name 'catmandu' --q "name any college"
# You need to specify the client version if your Elasticsearch server version is
# not the same as your default Search::Elasticsearch client version
$ catmandu import JSON to ElasticSearch --index-name 'catmandu' --client '5_0::Direct' < data.json
# From Perl
use Catmandu;
my $store = Catmandu->store('ElasticSearch', index_name => 'catmandu');
my $obj1 = $store->bag->add({ name => 'Patrick' });
printf "obj1 stored as %s\n" , $obj1->{_id};
# Force an id in the store
my $obj2 = $store->bag->add({ _id => 'test123' , name => 'Nicolas' });
# Commit all changes
$store->bag->commit;
$store->bag->delete('test123');
$store->bag->delete_all;
# All bags are iterators
$store->bag->each(sub { ... });
$store->bag->take(10)->each(sub { ... });
# Query the store using a simple ElasticSearch query
my $hits = $store->bag->search(query => '(content:this OR name:this) AND (content:that OR name:that)');
# Native queries are also supported by providing a hash of terms
# See the ElasticSearch manual for more examples
my $hits = $store->bag->search(
query => {
# All name.exact fields that start with 'test'
prefix => {
'name.exact' => 'test'
}
} ,
limit => 1000);
# Catmandu::Store::ElasticSearch supports CQL...
my $hits = $store->bag->search(cql_query => 'name any "Patrick"');METHODS
new(index_name => $name, [...])
new(index_name => $name , index_mapping => \%map, [...])
new(index_name => $name , ... , bags => { data => { cql_mapping => \%map } })
Create a new Catmandu::Store::ElasticSearch store connected to index $name. Optional extra ElasticSearch connection parameters will be passed on to the backend database.
Optionally provide an index_mapping which contains a ElasticSearch schema for each field in the index (See below).
Optionally provide for each bag a cql_mapping to map fields to CQL indexes.
drop
Deletes the Elasticsearch index backing this store. Calling functions after this may fail until this class is reinstantiated, creating a new index.
INHERITED METHODS
This Catmandu::Store implements:
Each Catmandu::Bag in this Catmandu::Store implements:
INDEX MAP
The index_mapping contains a Elasticsearch schema mappings for each bag defined in the index. E.g.
{
data => {
properties => {
_id => {
type => 'string',
include_in_all => 'true',
index => 'not_analyzed'
} ,
title => {
type => 'string'
}
}
}
}In the example above the default 'data' bag of the ElasticSearch contains an '_id' field of type 'string' which is stored automatically also in the '_all' search field. The '_id' is not analyzed. The bag also contains a 'title' field of type string.
See https://www.elastic.co/guide/en/elasticsearch/reference/2.2/mapping.html for more information on mappings.
These mappings can be passed inside a Perl program, or be written into a Catmandu 'catmandu.yml' configuration file. E.g.
# catmandu.yml
store:
search:
package: ElasticSearch
options:
index_name: catmandu
index_mappings
data:
properties:
_id:
type: string
include_in_all: true
index: not_analyzed
title:
type: stringVia the command line these configuration parameters can be read in by using the name of the store, search in this case:
$ catmandu import JSON to search < data.json
$ catmandu export search to JSON > data.jsonCQL MAP
Catmandu::Store::ElasticSearch supports CQL searches when a cql_mapping is provided for each bag. This hash contains a translation of CQL fields into Elasticsearch searchable fields.
# Example mapping
{
indexes => {
title => {
op => {
'any' => 1 ,
'all' => 1 ,
'=' => 1 ,
'<>' => 1 ,
'exact' => {field => [qw(mytitle.exact myalttitle.exact)]}
} ,
field => 'mytitle',
sort => 1,
cb => ['Biblio::Search', 'normalize_title']
}
}
}The CQL mapping above will support for the 'title' field the CQL operators: any, all, =, <> and exact.
The 'title' field will be mapping into the Elasticsearch field 'mytitle', except for the 'exact' operator. In case of 'exact' we will search both the 'mytitle.exact' and 'myalttitle.exact' fields.
The CQL mapping allows for sorting on the 'title' field. If, for instance, we would like to use a special ElasticSearch field for sorting we could have written "sort => { field => 'mytitle.sort' }".
The callback field cb contains a reference to subroutines to rewrite or augment a search query. In this case, the Biblio::Search package contains a normalize_title subroutine which returns a string or an ARRAY of strings with augmented title(s). E.g.
package Biblio::Search;
sub normalize_title {
my ($self,$title) = @_;
my $new_title =~ s{[^A-Z0-9]+}{}g;
$new_title;
}
1;Also this configuration can be added to a catmandu.yml configuration file like:
# catmandu.yml
store:
search:
package: ElasticSearch
options:
client: 6_0::Direct
index_name: catmandu
index_mappings:
data:
properties:
title:
type: text
bags:
data:
cql_mapping:
indexes:
title:
op:
'any': true
'all': true
'=': true
'<>': true
'exact':
field: [ 'mytitle.exact' , 'myalttitle.exact' ]
field: mytitle
sort: true
cb: [ 'Biblio::Search' , 'normalize_title' ]
}Via the command line these configuration parameters can be read in by using the name of the store, search in this case:
$ catmandu export search -q 'title any blablabla' to JSON > data.jsonCOMPATIBILITY
The appropriate client should be installed:
# Elasticsearch 6.x
cpanm Search::Elasticsearch::Client::6_0::Direct
# Elasticsearch 1.x
cpanm Search::Elasticsearch::Client::1_0::DirectAnd specified in the options:
Catmandu::Store::ElasticSearch->new(index_name => 'myindex', client => '1_0::Direct')If you want to use the delete_by_query method with Elasticsearch >= 2.0 you have to install the delete by query plugin.
ERROR HANDLING
Error handling can be activated by specifying an error handling callback for index when creating a store. E.g. to create an error handler for the bag 'data' index use:
my $error_handler = sub {
my ($action, $response, $i) = @_;
do_something_with_error($response);
};
my $store = Catmandu::Store::ElasticSearch->new(
index_name => 'catmandu'
bags => { data => { on_error => $error_handler } }
});Instead of a callback, the following shortcuts are also accepted for on_error:
log: log the response
throw: throw the response as an error
ignore: do nothing
my $store = Catmandu::Store::ElasticSearch->new(
index_name => 'catmandu'
bags => { data => { on_error => 'log' } }
});SEE ALSO
AUTHOR
Nicolas Steenlant, <nicolas.steenlant at ugent.be>
CONTRIBUTORS
- Dave Sherohman,
dave.sherohman at ub.lu.se - Robin Sheat,
robin at kallisti.net.nz - Patrick Hochstenbach,
patrick.hochstenbach at ugent.be
LICENSE AND COPYRIGHT
This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.