Question - How do I delete shards in Elasticsearch?

Answered by: Betty Coleman  |  Category: General  |  Last Updated: 07-09-2021  |  Views: 1081  |  Total Questions: 13

There is no “delete shard” API call in Elasticsearch, but there is a command to allocate an empty primary shard on a particular data node, which is effectively the same thing, except that you need to tell Elasticsearch which node the new shard should be assigned to. You can also delete the index using DELETE action in 'elasticsearch head' (Chrome plugin ). Add it to your chrome and connect it to your host. There you will find all your indices and if you click on actions button below the index you want to delete, you will find a DELETE option in the drop down. Technically speaking, a shard is an index in Lucene which is the core component Elasticsearch is built upon. When you are indexing data into an Elasticsearch(ES) index, ES will distribute the data into multiple lucene indexes. In this scenario, you have to decide how to proceed: try to get the original node to recover and rejoin the cluster (and do not force allocate the primary shard), or force allocate the shard using the Cluster Reroute API and reindex the missing data using the original data source, or from a backup. A good rule-of-thumb is to ensure you keep the number of shards per node below 20 per GB heap it has configured. A node with a 30GB heap should therefore have a maximum of 600 shards, but the further below this limit you can keep it the better. This will generally help the cluster stay in good health.

https://stackoverflow.com/questions/33303786/where-does-elastic-search-store-its-data

7 Answers. If you're on Windows or if you've simply extracted ES from the ZIP/TGZ file, then you should have a data sub-folder in the extraction folder. According to the documentation the data is stored in a folder called "data" in the elastic search root directory.

https://marutitech.com/elasticsearch-can-helpful-business/

ES (Elasticsearch) is a document-oriented database, designed to store, retrieve and manage document oriented or semi-structured data. When you use Elasticsearch you store data in JSON document form. Then you query them for retrieval.

https://docs.microsoft.com/en-us/sql/relational-databases/indexes/delete-an-index

To delete an index by using Object Explorer In Object Explorer, expand the database that contains the table on which you want to delete an index. Expand the Tables folder. Expand the table that contains the index you want to delete. Expand the Indexes folder. Right-click the index you want to delete and select Delete.

https://postmarkapp.com/blog/tools-we-use-curator-for-elasticsearch

Curator is a tool from Elastic (the company behind Elasticsearch) to help manage your Elasticsearch cluster. Installation is a breeze with a pip install elasticsearch-curator. That provides you with the curator command that you can use.

https://www.elastic.co/guide/en/elasticsearch/reference/current/getting-started-search.html

Start searchingedit. Once you have ingested some data into an Elasticsearch index, you can search it by sending requests to the _search endpoint. To access the full suite of search capabilities, you use the Elasticsearch Query DSL to specify the search criteria in the request body.

https://note.nkmk.me/en/python-list-clear-pop-remove-del/

Remove items by index or slice: del Specify the item to be deleted by index. The first index is 0, and the last index is -1. Using slice, you can delete multiple items at once. It is also possible to delete all items by specifying the entire range.

https://www.roseindia.net/answers/viewqa/bigdata/33024-rename-index-in-elasticsearch.html

Elasticsearch does not allow to rename the index. But you can copy index into another index and then delete old index.

https://medium.com/@manis.eren/elasticsearch-issue-unassigned-shards-because-of-max-retry-24421c1d7f

Elasticsearch issue: Unassigned shards because of max_retry. When we create index, or have one of our nodes crashed, shards may go into unassigned state. Meaning, data is there but it is not assigned/replicated to a node to enable processing that shard.

https://aws.amazon.com/premiumsupport/knowledge-center/elasticsearch-red-yellow-status/

Red status: A red cluster status means that at least one primary shard and its replicas aren't allocated to a node. For more information, see Red Cluster Status. Yellow status: A yellow cluster status means that replica shards for at least one index aren't allocated to nodes.

http://blog.ruanbekker.com/blog/2019/04/06/shrink-your-elasticsearch-index-by-reducing-the-shard-cou

Steps on Shrinking: Create the target index with the same definition as the source index, but with a smaller number of primary shards. Then it hard-links segments from the source index into the target index. Finally, it recovers the target index as though it were a closed index which had just been re-opened.

https://medium.com/hipages-engineering/scaling-elasticsearch-b63fa400ee9e

One of the great features of Elasticsearch is that it's designed from the ground up to be horizontally scalable, meaning that by adding more nodes to the cluster you're capable to grow the capacity of the cluster (as opposed to vertical scalability that requires you to have bigger machines to be able to grow your

https://stackoverflow.com/questions/15694724/shards-and-replicas-in-elasticsearch

An index is broken into shards in order to distribute them and scale. Replicas are copies of the shards. A node is a running instance of elastic search which belongs to a cluster. A cluster consists of one or more nodes which share the same cluster name.