I am trying to retrieve the mapping for an index as follows:
GET /twitter/_mapping/_doc
However there is no dynamic field for me to check whether the dynamic mapping type applied (strict / false / true).
How can I verify my dynamic mapping type?
As explained in the documentation on dynamic field mappings, if the dynamic setting is not specified (hence not returned by the _mapping call), the default value is true, which means that new fields will be created in the mapping if they don't exist yet.
Related
I have an index created by ElasticSearch 6.8.7. I query against some fields which don't correspond to document's fields, because they are merged copies of document's ones. At index creation their store value was set to false. Now I need to get highlights, but the query fields content is not stored. Can I update mapping and set store to true? Index's _source is enabled.
The docs don't mention this ability, and I can't try to update store on my production cluster.
No, it's not.
In general, the mapping for existing fields cannot be updated. There
are some exceptions to this rule. For instance:
new properties can be added to Object datatype fields.
new multi-fields can be added to existing fields.
the ignore_above parameter can be updated.
Source.
Also, I tried to update mapping on a sample index, and ES didn't allow me to update store value of an existing field.
That is understandable, but still sad.
i am running Packet-beat in my server.
i'm disabled dynamic field in index mapping . it mean if new data coming . don't create new fields.
in my mapping there is not extra field but when i send a request from postman for show records . there is a new field in my result but i'm sure its not in my mapping.
how is possible?
I'm founding the answer.
in elasticsearch when set dynamic:false its mean:
The dynamic setting controls whether new fields can be added dynamically or not. It accepts three settings:
true : Newly detected fields are added to the mapping. (default)
false : Newly detected fields are ignored. These fields will not be indexed so will not be searchable but will still appear in the _source field of returned hits. These fields will not be added to the mapping, new fields must be added explicitly.
strict : If new fields are detected, an exception is thrown and the document is rejected. New fields must be explicitly added to the mapping.
extra description in this link
Currently, I've been defining the tokenizer analyzer upon index creation settings/mapping. Would it be possible to just define the tokenizer on class property attribute and let automap do the work?
An analyzer can be defined on a TextAttribute applied to a string property, and a tokenizer is one component in an analyzer, so it doesn't make sense to apply on a mapping attribute outside of the context of an analyzer.
A tokenizer has to be defined in the index in which it will be used, so is supplied upon index creation, or when updating the index settings. The important bit is that what is in the index settings in Elasticsearch matches what is defined on your POCO in your application. You might implement some logic that gets the index settings on startup and compares the analysis settings and mappings against the index and mapping settings defined in the application, and take some action if they are different.
I was wondering what is the recommended approach to filter out some of the fields that are sent to Elasticsearch from Store and Index?
I want to filter our some fields from getting indexed in Elasticsearch. You may ask why you are sending them to Elasticsearch from the first place. Unfortunately, it is sent via another application that doesn't accept any filtering mechanism. Hence, filtering should be addressed at the time of indexing. Here is what we have done, but I am not sure what would be the consequences of these steps:
1- Disable dynamic mapping ("dynamic": "false" ) in ES templates.
2- Including only the required fields in _source and excluding the rest.
According to ES website, some of the ES functionalities will be disabled by disabling _source fields. Given I don't need the filtered fields at all, I was wondering whether the mentioned solution will break anything regarding the remaining fields or not?
There are a few mapping parameters that allow you to do what you want:
index: true/false: if true the field value is indexed in order to be searched later on (default: true)
store: true/false: if true the field values are stored in addition to being indexed. Usually, the field values are stored in the source already, but you can choose to not store the source but store the field value itself (default: false)
enabled: true/false: only for the mapping type as a whole or for object types. you can decide whether to only store the value but not index it
So you can use any combination of the above parameters if you don't want to modify the source documents and simple let ES do it for you.
I have a document whose structure changes often, how can I index nested documents inside it without changing the mapping on ElasticSearch?
You can index documents in Elasticsearch without providing a mapping yes.
However, Elasticsearch makes a decision about the type of a field when the first document contains a value for that field. If you add document 1 and it has a field called item_code, and in document 1 item_code is a string, Elasticsearch will set the type of field "item_code" to be string. If document 2 has an integer value in item_code Elasticsearch will have already set the type as string.
Basically, field type is index dependant, not document dependant.
This is mainly because of Apache Lucene and the way it handles this information.
If you're having a case where some data structure changes, while other doesn't, you could use an object type, http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/mapping-object-type.html.
You can even go as far as to use "enabled": false on it, which makes elasticsearch just store the data. You couldn't search it anymore, but maybe you actually don't even want that?