Catmandu::Store::ElasticSearch - A searchable store backed by Elasticsearch
# 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"
# 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"');
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.
Deletes the Elasticsearch index backing this store. Calling functions after this may fail until this class is reinstantiated, creating a new index.
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: string
Via 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.json
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:
index_name: catmandu
index_mappings
data:
properties:
_id:
type: string
include_in_all: true
index: not_analyzed
title:
type: string
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.json
This store expects version 1.0 or higher of the Elasticsearch server.
To talk to older versions of Elasticsearch the approriate client should be installed.
# Elasticsearch 2.x
cpanm Search::Elasticsearch::Client::2_0::Direct
# Elasticsearch 1.x
cpanm Search::Elasticsearch::Client::1_0::Direct
And the client version should be specified in the options:
Catmandu::Store::ElasticSearch->new(index_name => 'myindex', client => '1_0::Direct')
Note that Elasticsearch >= 2.0 doesn't allow keys that start with an underscore such as
_id. You can use the key_prefix option at store level or id_prefix at
bag level to handle this.
# in your catmandu.yml
store:
yourstore:
package: ElasticSearch
options:
# use my_id instead of _id
key_prefix: my_
If you want to use the delete_by_query method with Elasticsearch >= 2.0 you
need have to install the delete by query plugin.
1. backup your data as JSON
catmandu export yourstore --bag yourbag to --file /path/to/yourbag.json -v
2. drop the store
catmandu drop yourstore
3. upgrade the Elasticsearch server
4. update your catmandu.yml with a key_prefix or id_prefix (see COMPATIBILITY)
5. import your data using the new keys specified in your catmandu.yml
catmandu import --file /path/to/yourbag.json --fix 'move_field(_id, my_id)' \
to yourstore --bag yourbag -v
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 $store = Catmandu::Store::ElasticSearch->new(
index_name => 'catmandu'
bags => { data => { on_error => \&error_handler } }
});
sub error_handler {
my ($action, $response, $i) = @_;
}
Nicolas Steenlant, <nicolas.steenlant at ugent.be>
- Dave Sherohman,
dave.sherohman at ub.lu.se - Robin Sheat,
robin at kallisti.net.nz - Patrick Hochstenbach,
patrick.hochstenbach at ugent.be
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.