Provided by: libsearch-elasticsearch-client-2-0-perl_6.81-1_all 
NAME
Search::Elasticsearch::Client::2_0::Bulk - A helper module for the Bulk API and for reindexing
VERSION
version 6.81
SYNOPSIS
use Search::Elasticsearch;
my $es = Search::Elasticsearch->new;
my $bulk = $es->bulk_helper(
index => 'my_index',
type => 'my_type'
);
# Index docs:
$bulk->index({ id => 1, source => { foo => 'bar' }});
$bulk->add_action( index => { id => 1, source => { foo=> 'bar' }});
# Create docs:
$bulk->create({ id => 1, source => { foo => 'bar' }});
$bulk->add_action( create => { id => 1, source => { foo=> 'bar' }});
$bulk->create_docs({ foo => 'bar' })
# Delete docs:
$bulk->delete({ id => 1});
$bulk->add_action( delete => { id => 1 });
$bulk->delete_ids(1,2,3)
# Update docs:
$bulk->update({ id => 1, script => '...' });
$bulk->add_action( update => { id => 1, script => '...' });
# Manual flush
$bulk->flush;
# Reindex docs:
my $bulk = $es->bulk_helper(
index => 'new_index',
verbose => 1
);
$bulk->reindex( source => { index => 'old_index' });
DESCRIPTION
This module provides a wrapper for the "bulk()" in Search::Elasticsearch::Client::2_0::Direct method
which makes it easier to run multiple create, index, update or delete actions in a single request. It
also provides a simple interface for reindexing documents.
The Search::Elasticsearch::Client::2_0::Bulk module acts as a queue, buffering up actions until it
reaches a maximum count of actions, or a maximum size of JSON request body, at which point it issues a
"bulk()" request.
Once you have finished adding actions, call "flush()" to force the final "bulk()" request on the items
left in the queue.
This class does Search::Elasticsearch::Client::2_0::Role::Bulk and Search::Elasticsearch::Role::Is_Sync.
CREATING A NEW INSTANCE
"new()"
my $bulk = $es->bulk_helper(
index => 'default_index', # optional
type => 'default_type', # optional
%other_bulk_params # optional
max_count => 1_000, # optional
max_size => 1_000_000, # optional
max_time => 5, # optional
verbose => 0 | 1, # optional
on_success => sub {...}, # optional
on_error => sub {...}, # optional
on_conflict => sub {...}, # optional
);
The "new()" method returns a new $bulk object. You must pass your Search::Elasticsearch client as the
"es" argument.
The "index" and "type" parameters provide default values for "index" and "type", which can be overridden
in each action. You can also pass any other values which are accepted by the bulk() method.
See "flush()" for more information about the other parameters.
FLUSHING THE BUFFER
"flush()"
$result = $bulk->flush;
The "flush()" method sends all buffered actions to Elasticsearch using a bulk() request.
Auto-flushing
An automatic "flush()" is triggered whenever the "max_count", "max_size", or "max_time" threshold is
breached. This causes all actions in the buffer to be sent to Elasticsearch.
• "max_count"
The maximum number of actions to allow before triggering a "flush()". This can be disabled by
setting "max_count" to 0. Defaults to "1,000".
• "max_size"
The maximum size of JSON request body to allow before triggering a "flush()". This can be disabled
by setting "max_size" to 0. Defaults to "1_000,000" bytes.
• "max_time"
The maximum number of seconds to wait before triggering a flush. Defaults to 0 seconds, which means
that it is disabled. Note: This timeout is only triggered when new items are added to the queue, not
in the background.
Errors when flushing
There are two types of error which can be thrown when "flush()" is called, either manually or
automatically.
• Temporary Elasticsearch errors
A "Cxn" error like a "NoNodes" error which indicates that your cluster is down. These errors do not
clear the buffer, as they can be retried later on.
• Action errors
Individual actions may fail. For instance, a "create" action will fail if a document with the same
"index", "type" and "id" already exists. These action errors are reported via callbacks.
Using callbacks
By default, any Action errors (see above) cause warnings to be written to "STDERR". However, you can use
the "on_error", "on_conflict" and "on_success" callbacks for more fine-grained control.
All callbacks receive the following arguments:
$action
The name of the action, ie "index", "create", "update" or "delete".
$response
The response that Elasticsearch returned for this action.
$i The index of the action, ie the first action in the flush request will have $i set to 0, the second
will have $i set to 1 etc.
"on_success"
my $bulk = $es->bulk_helper(
on_success => sub {
my ($action,$response,$i) = @_;
# do something
},
);
The "on_success" callback is called for every action that has a successful response.
"on_conflict"
my $bulk = $es->bulk_helper(
on_conflict => sub {
my ($action,$response,$i,$version) = @_;
# do something
},
);
The "on_conflict" callback is called for actions that have triggered a "Conflict" error, eg trying to
"create" a document which already exists. The $version argument will contain the version number of the
document currently stored in Elasticsearch (if found).
"on_error"
my $bulk = $es->bulk_helper(
on_error => sub {
my ($action,$response,$i) = @_;
# do something
},
);
The "on_error" callback is called for any error (unless the "on_conflict") callback has already been
called).
Disabling callbacks and autoflush
If you want to be in control of flushing, and you just want to receive the raw response that
Elasticsearch sends instead of using callbacks, then you can do so as follows:
my $bulk = $es->bulk_helper(
max_count => 0,
max_size => 0,
on_error => undef
);
$bulk->add_actions(....);
$response = $bulk->flush;
CREATE, INDEX, UPDATE, DELETE
"add_action()"
$bulk->add_action(
create => { ...params... },
index => { ...params... },
update => { ...params... },
delete => { ...params... }
);
The "add_action()" method allows you to add multiple "create", "index", "update" and "delete" actions to
the queue. The first value is the action type, and the second value is the parameters that describe that
action. See the individual helper methods below for details.
Note: Parameters like "index" or "type" can be specified as "index" or as "_index", so the following two
lines are equivalent:
index => { index => 'index', type => 'type', id => 1, source => {...}},
index => { _index => 'index', _type => 'type', _id => 1, _source => {...}},
Note: The "index" and "type" parameters can be specified in the params for any action, but if not
specified, will default to the "index" and "type" values specified in "new()". These are required
parameters: they must be specified either in "new()" or in every action.
"create()"
$bulk->create(
{ index => 'custom_index', source => { doc body }},
{ type => 'custom_type', id => 1, source => { doc body }},
...
);
The "create()" helper method allows you to add multiple "create" actions. It accepts the same parameters
as "create()" in Search::Elasticsearch::Client::2_0::Direct except that the document body should be
passed as the "source" or "_source" parameter, instead of as "body".
"create_docs()"
$bulk->create_docs(
{ doc body },
{ doc body },
...
);
The "create_docs()" helper is a shorter form of "create()" which can be used when you are using the
default "index" and "type" as set in "new()" and you are not specifying a custom "id" per document. In
this case, you can just pass the individual document bodies.
"index()"
$bulk->index(
{ index => 'custom_index', source => { doc body }},
{ type => 'custom_type', id => 1, source => { doc body }},
...
);
The "index()" helper method allows you to add multiple "index" actions. It accepts the same parameters
as "index()" in Search::Elasticsearch::Client::2_0::Direct except that the document body should be passed
as the "source" or "_source" parameter, instead of as "body".
"delete()"
$bulk->delete(
{ index => 'custom_index', id => 1},
{ type => 'custom_type', id => 2},
...
);
The "delete()" helper method allows you to add multiple "delete" actions. It accepts the same parameters
as "delete()" in Search::Elasticsearch::Client::2_0::Direct.
"delete_ids()"
$bulk->delete_ids(1,2,3...)
The "delete_ids()" helper method can be used when all of the documents you want to delete have the
default "index" and "type" as set in "new()". In this case, all you have to do is to pass in a list of
IDs.
"update()"
$bulk->update(
{ id => 1,
doc => { partial doc },
doc_as_upsert => 1
},
{ id => 2,
lang => 'mvel',
script => { script }
upsert => { upsert doc }
},
...
);
The "update()" helper method allows you to add multiple "update" actions. It accepts the same parameters
as "update()" in Search::Elasticsearch::Client::2_0::Direct. An update can either use a partial doc
which gets merged with an existing doc (example 1 above), or can use a "script" to update an existing doc
(example 2 above). More information on "script" can be found here: "update()" in
Search::Elasticsearch::Client::2_0::Direct.
REINDEXING DOCUMENTS
A common use case for bulk indexing is to reindex a whole index when changing the type mappings or
analysis chain. This typically combines bulk indexing with scrolled searches: the scrolled search pulls
all of the data from the source index, and the bulk indexer indexes the data into the new index.
"reindex()"
$bulk->reindex(
source => $source, # required
transform => \&transform, # optional
version_type => 'external|internal', # optional
);
The "reindex()" method requires a $source parameter, which provides the source for the documents which
are to be reindexed.
Reindexing from another index
If the "source" argument is a HASH ref, then the hash is passed to "new()" in
Search::Elasticsearch::Client::2_0::Scroll to create a new scrolled search.
my $bulk = $es->bulk_helper(
index => 'new_index',
verbose => 1
);
$bulk->reindex(
source => {
index => 'old_index',
size => 500, # default
search_type => 'scan' # default
}
);
If a default "index" or "type" has been specified in the call to "new()", then it will replace the
"index" and "type" values for the docs returned from the scrolled search. In the example above, all docs
will be retrieved from "old_index" and will be bulk indexed into "new_index".
Reindexing from a generic source
The "source" parameter also accepts a coderef or an anonymous sub, which should return one or more new
documents every time it is executed. This allows you to pass any iterator, wrapped in an anonymous sub:
my $iter = get_iterator_from_somewhere();
$bulk->reindex(
source => sub { $iter->next }
);
Transforming docs on the fly
The "transform" parameter allows you to change documents on the fly, using a callback. The callback
receives the document as the only argument, and should return the updated document, or "undef" if the
document should not be indexed:
$bulk->reindex(
source => { index => 'old_index' },
transform => sub {
my $doc = shift;
# don't index doc marked as valid:false
return undef unless $doc->{_source}{valid};
# convert $tag to @tags
$doc->{_source}{tags} = [ delete $doc->{_source}{tag}];
return $doc
}
);
Reindexing from another cluster
By default, "reindex()" expects the source and destination indices to be in the same cluster. To pull
data from one cluster and index it into another, you can use two separate $es objects:
$es_target = Search::Elasticsearch->new( nodes => 'localhost:9200' );
$es_source = Search::Elasticsearch->new( nodes => 'search1:9200' );
my $bulk = $es_targert->bulk_helper(
verbose => 1
)
-> reindex(
source => {
es => $es_source,
index => 'my_index'
}
);
Parents and routing
If you are using parent-child relationships or custom "routing" values, and you want to preserve these
when you reindex your documents, then you will need to request these values specifically, as follows:
$bulk->reindex(
source => {
index => 'old_index',
fields => ['_source','_parent','_routing']
}
);
Working with version numbers
Every document in Elasticsearch has a current "version" number, which is used for optimistic concurrency
control <http://en.wikipedia.org/wiki/Optimistic_concurrency_control>, that is, to ensure that you don't
overwrite changes that have been made by another process.
All CRUD operations accept a "version" parameter and a "version_type" parameter which tells Elasticsearch
that the change should only be made if the current document corresponds to these parameters. The
"version_type" parameter can have the following values:
• "internal"
Use Elasticsearch version numbers. Documents are only changed if the document in Elasticsearch has
the same "version" number that is specified in the CRUD operation. After the change, the new version
number is "version+1".
• "external"
Use an external versioning system, such as timestamps or version numbers from an external database.
Documents are only changed if the document in Elasticsearch has a lower "version" number than the one
specified in the CRUD operation. After the change, the new version number is "version".
If you would like to reindex documents from one index to another, preserving the "version" numbers from
the original index, then you need the following:
$bulk->reindex(
source => {
index => 'old_index',
version => 1, # retrieve version numbers in search
},
version_type => 'external' # use these "external" version numbers
);
AUTHOR
Enrico Zimuel <enrico.zimuel@elastic.co>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2020 by Elasticsearch BV.
This is free software, licensed under:
The Apache License, Version 2.0, January 2004
perl v5.32.0 2020-11-25 Search::Elastic...ient::2_0::Bulk(3pm)