Elasticsearch Backup And Restore

How To Take Elasticsearch Backup (Snapshot) And Restore

This post is about "How to take Elasticsearch backup and restore it back".

Video Tutorial:

Elasticsearch Installation

brew is a tool on mac to install stuff. As Elasticsearch requires Java, we need to install java first and than Elasticsearch.

brew update
brew cask install java
brew search elasticsearch


elasticsearch                    

homebrew/versions/elasticsearch24

homebrew/versions/elasticsearch17

brew install homebrew/versions/elasticsearch17

Check if elasticsearch has installed or not.

brew info elasticsearch

Creating first document with index

nameindex - name of the index

names - The "type" having similar data/info

myid - The id for the data

pretty - Simply means we want well-formatted output

curl -XPOST 'localhost:9200/nameindex/names/myid?pretty' -d '
{
    "name": "Ajeet",
    "email_address": "ajeet@example.com"
}'







If you insert another record with the same id "myid" than existing record will get updated.

Creating A Document without "id"

curl -XPOST 'localhost:9200/nameindex/names?pretty' -d '
{
    "name": "no_id",
    "email_address": "no_id@example.com"
}'





As you can see it has automatically generated the "id".

Backup & Resotre

For Backup we need to create two repository (logical and physical).
Let's create the physical repository

mkdir es_backup

This would be the parent directory which will have all backups.

Now we will tell elasticsearch, the path of our repository in config file.

vi /usr/local/Cellar/elasticsearch17/1.7.5/config/elasticsearch.yml

add the repository path:

path.repo: /Users/zombie/es_bakcup

save and exit.
Check if any snapshot is present 

curl localhost:9200/_snapshot

The output would be blank as we have not taken any snapshot yet.

Snapshot can be taken for few or a particular index or of the whole cluster. To take backup index-wise create sub-directory inside the parent repository.




Now we will create logical repository. Here we will take snapshot of particular index "nameindex"




Restart elasticsearch to take path.repo changes and run the following to register the repository:

curl -XPUT 'localhost:9200/_snapshot/nameindexbackup' -d '{
    "type": "fs",
    "settings": {
        "location": "nameindex",
        "compress": "true"
    }
}'


No need to specify the full path in "location" as we have already specified it in the config file path.repo.

This will create the logical repository which you can check in the parent folder. A sub directory must have been created with name "nameindex".






Now we will take the backup

CURL -XPUT 'localhost:9200/_snapshot/nameindexbackup/12nov16' -d '{
    "indices": "nameindex",
    "ignore_unavailable": true,
    "include_global_state": false
}'

indices field may have multiple index with comma separated values.
ignore_unavailable means don't stop the snapshot process if any shards is not available.
include_global_state means take snapshot of cluster status also. If the status is yellow than while restore the yellow status will be there. If you don't want this than set it to false.






To check if snapshot is completed or not fire a GET request



curl localhost:9200/_snapshot/nameindexbackup/12nov16





Restore the Snapshot

First delete the data from elasticsearch



curl -XDELETE localhost:9200/nameindex

Now if you throw a GET request you will get 404. 
Let's restore the index now.

curl -XPOST localhost:9200/_snapshot/nameindexbackup/12nov16/_restore



Now do a GET request if data is restored or not.






We have successfully restored the elasticsearch data.

During restore you can also provide certain information 

curl -XPOST 'localhost:9200/_snapshot/nameindexbackup/12nov16/_restore' -d '{
    "indices": "index_1,index_2",
    "ignore_unavailable": true,
    "include_global_state": true,
    "rename_pattern": "index_(.+)",
    "rename_replacement": "restored_index_$1"
}'
This is how snapshot and restore works in Elasticsearch. Any doubts or suggestions are welcome in the comment box.