deployment instructions<\/a> in a separate tutorial.<\/p>\n\n\n\nInstalling Elasticsearch<\/h2>\n\n\n\n
Once your Cloud Server is up and running, connect to it using SSH. Afterwards, you can get started by adding the Elasticsearch repository.<\/p>\n\n\n\n
wget -qO - https:\/\/artifacts.elastic.co\/GPG-KEY-elasticsearch | sudo apt-key add -<\/pre>\n\n\n\necho \"deb https:\/\/artifacts.elastic.co\/packages\/7.x\/apt stable main\" | sudo tee -a \/etc\/apt\/sources.list.d\/elastic-7.x.list<\/pre>\n\n\n\nNext, update the repo lists to include the new source.<\/p>\n\n\n\n
sudo apt update<\/pre>\n\n\n\nThen install Elasticsearch with the command below.<\/p>\n\n\n\n
sudo apt install elasticsearch<\/pre>\n\n\n\nWhen the installation is done, you will likely want to configure Elasticsearch for your use case. Head over to the next section to continue.<\/p>\n\n\n\n
Configuring Elasticsearch<\/h2>\n\n\n\n
After installing Elasticsearch, you are almost ready to get cracking. However, depending on your use case and requirements, you might want to have a look at the settings.<\/p>\n\n\n\n
Open the elasticsearch.yml<\/em> file in a text editor.<\/p>\n\n\n\nsudo nano \/etc\/elasticsearch\/elasticsearch.yml<\/pre>\n\n\n\nFirst things first, you should name your cluster and the node you are configuring.<\/p>\n\n\n\n
A node can only join a cluster if it shares the cluster.name<\/em> with all the other nodes in the cluster. You should name your cluster appropriately to describe the purpose of the cluster.<\/p>\n\n\n\n# -------------------------------- Cluster ----------------------------------\n#\n# Use a descriptive name for your cluster:\n#\ncluster.name: example-cluster\n#<\/pre>\n\n\n\nThe node.name<\/em> is used as a human-readable identifier for the nodes in the Elasticsearch cluster. By default, the node.name<\/em> is set to the hostname of the server but can be configured manually.<\/p>\n\n\n\n# --------------------------------- Node ------------------------------------\n#\n# Use a descriptive name for the node:\n#\nnode.name: node-1\n#\n<\/pre>\n\n\n\nBy default, Elasticsearch is only accessible from localhost or the IP address 127.0.0.1. If you want to query it from another server or your local computer, you\u2019ll need to set the network.host<\/em> to an appropriate IP address.<\/p>\n\n\n\n# -------------------------------- Network ----------------------------------\n#\n# By default Elasticsearch is only accessible on localhost. Set a different\n# address here to expose this node on the network:\n#\n#network.host: 192.168.0.1\n#<\/pre>\n\n\n\nYou also have the option to change the default port 9200 according to your preferences. If you do set a custom port, remember to configure your firewall accordingly.<\/p>\n\n\n\n
# By default Elasticsearch listens for HTTP traffic on the first free port it\n# finds starting at 9200. Set a specific HTTP port here:\n#\n#http.port: 9200\n#\n# For more information, consult the network module documentation.<\/pre>\n\n\n\nOnce you are done with the settings, save the file and exit the editor.<\/p>\n\n\n\n
Then start the Elasticsearch service and enable it to start at boot.<\/p>\n\n\n\n
sudo systemctl start elasticsearch\nsudo systemctl enable elasticsearch<\/pre>\n\n\n\nThe startup might take a few seconds but should complete without issue or output. Afterwards, you can check the status of the service with the following command.<\/p>\n\n\n\n
sudo systemctl status elasticsearch<\/pre>\n\n\n\nWith the Elasticsearch service running, continue with firewall configuration before getting to testing the search.<\/p>\n\n\n\n
Configuring firewall rules<\/h2>\n\n\n\n
If you enabled Elasticsearch on a public network, you should restrict access to the HTTP query port 9200 to just your IP addresses.<\/p>\n\n\n\n
Replace the <your-ip-address><\/em> in the following command with your public IP or the public IP of another server.<\/p>\n\n\n\nsudo ufw allow from <your-ip-address> to any port 9200<\/pre>\n\n\n\nRepeat the above allow command to include other IP addresses from where you want to have access.<\/p>\n\n\n\n
Also, make sure to allow SSH connections to make sure you are not locked out from your server.<\/p>\n\n\n\n
sudo ufw allow ssh<\/pre>\n\n\n\nThen enable the firewall and verify the enabled rules by checking the firewall status.<\/p>\n\n\n\n
sudo ufw enable<\/pre>\n\n\n\nsudo ufw status<\/pre>\n\n\n\nStatus: active\n\nTo Action From\n-- ------ ----\n9200 ALLOW <your-ip-address>\n22 ALLOW Anywhere\n22 (v6) ALLOW Anywhere (v6)<\/pre>\n\n\n\nWith the firewall configured, you can be sure unauthorised access attempts won\u2019t get through.<\/p>\n\n\n\n
Follow up by testing the Elasticsearch yourself.<\/p>\n\n\n\n
Testing the connection<\/h2>\n\n\n\n
The simplest way to query the Elasticsearch server is to use curl or another similar command-line HTTP tool.<\/p>\n\n\n\n
The following example command allows you to get the server details. Note that localhost is only accessible from within the Cloud Server itself. Replace the localhost with the public IP of the Cloud Server if you want to query Elasticsearch from an external source.<\/p>\n\n\n\n
curl -X GET 'http:\/\/localhost:9200'<\/pre>\n\n\n\n{\n \"name\" : \"elastic.example.com\",\n \"cluster_name\" : \"elasticsearch\",\n \"cluster_uuid\" : \"NCY3941lRtWECJTI_fASlw\",\n \"version\" : {\n \"number\" : \"7.12.1\",\n \"build_flavor\" : \"default\",\n \"build_type\" : \"deb\",\n \"build_hash\" : \"3186837139b9c6b6d23c3200870651f10d3343b7\",\n \"build_date\" : \"2021-04-20T20:56:39.040728659Z\",\n \"build_snapshot\" : false,\n \"lucene_version\" : \"8.8.0\",\n \"minimum_wire_compatibility_version\" : \"6.8.0\",\n \"minimum_index_compatibility_version\" : \"6.0.0-beta1\"\n },\n \"tagline\" : \"You Know, for Search\"\n}<\/pre>\n\n\n\nYou can also make further queries using the indexes.<\/p>\n\n\n\n
curl -X GET 'http:\/\/localhost:9200\/_nodes\/node-1\/name?pretty'<\/pre>\n\n\n\nNote the ?pretty<\/em> parameter at the end which is used to format the output making it easier to read on the command line. Without that, all output will be printed into a single line.<\/p>\n\n\n\nQuerying the database<\/h2>\n\n\n\n
Now that we have a working Elasticsearch node up and running, let\u2019s input some data we can use to test it.<\/p>\n\n\n\n
Create a new index<\/strong> with an attached message using the following command.<\/p>\n\n\n\ncurl -X POST -H 'Content-Type: application\/json' 'localhost:9200\/example\/helloworld\/1?pretty' -d '{ \"message\": \"Hello world!\" }'<\/pre>\n\n\n\nYou should get an output similar to the one below to confirm.<\/p>\n\n\n\n
{\n \"_index\" : \"example\",\n \"_type\" : \"helloworld\",\n \"_id\" : \"1\",\n \"_version\" : 1,\n \"result\" : \"created\",\n \"_shards\" : {\n \"total\" : 2,\n \"successful\" : 1,\n \"failed\" : 0\n },\n \"_seq_no\" : 0,\n \"_primary_term\" : 1\n}<\/pre>\n\n\n\nQuery the index<\/strong> directly for the input we just made by using the command below.<\/p>\n\n\n\ncurl -X GET -H 'Content-Type: application\/json' 'localhost:9200\/example\/helloworld\/1?pretty'<\/pre>\n\n\n\n{\n \"_index\" : \"example\",\n \"_type\" : \"helloworld\",\n \"_id\" : \"1\",\n \"_version\" : 1,\n \"_seq_no\" : 0,\n \"_primary_term\" : 1,\n \"found\" : true,\n \"_source\" : {\n \"message\" : \"Hello World!\"\n }\n}<\/pre>\n\n\n\nSearch the database<\/strong> for the same data using the query below. The command is split between multiple lines for legibility, copy the whole thing as a single command.<\/p>\n\n\n\ncurl -X POST -H 'Content-Type: application\/json' 'localhost:9200\/_search?pretty' -d'\n{\n \"query\": {\n \"match\": {\n \"_type\": \"helloworld\"\n }\n }\n}'<\/pre>\n\n\n\n{\n \"took\" : 25,\n \"timed_out\" : false,\n \"_shards\" : {\n \"total\" : 1,\n \"successful\" : 1,\n \"skipped\" : 0,\n \"failed\" : 0\n },\n \"hits\" : {\n \"total\" : {\n \"value\" : 1,\n \"relation\" : \"eq\"\n },\n \"max_score\" : 1.0,\n \"hits\" : [\n {\n \"_index\" : \"example\",\n \"_type\" : \"helloworld\",\n \"_id\" : \"1\",\n \"_score\" : 1.0,\n \"_source\" : {\n \"message\" : \"Hello world!\"\n }\n }\n ]\n }\n}<\/pre>\n\n\n\nThe output of the search shows the number of hits your search had and lists the results.<\/p>\n\n\n\n
You can also make changes to the data in the previous index.<\/p>\n\n\n\n
Edit the index<\/strong> by changing the message with the next command.<\/p>\n\n\n\ncurl -X PUT -H \"Content-Type: application\/json\" 'localhost:9200\/example\/helloworld\/1?pretty' -d '{ \"message\": \"Hello again!\" }'<\/pre>\n\n\n\n{\n \"_index\" : \"example\",\n \"_type\" : \"helloworld\",\n \"_id\" : \"1\",\n \"_version\" : 2,\n \"result\" : \"updated\",\n \"_shards\" : {\n \"total\" : 2,\n \"successful\" : 1,\n \"failed\" : 0\n },\n \"_seq_no\" : 2,\n \"_primary_term\" : 1\n}<\/pre>\n\n\n\nThen check that the changes were saved by querying the index again. E.g. with the following command.<\/p>\n\n\n\n
curl -X GET -H \"Content-Type: application\/json\" 'localhost:9200\/example\/helloworld\/1?pretty'<\/pre>\n\n\n\n{\n \"_index\" : \"example\",\n \"_type\" : \"helloworld\",\n \"_id\" : \"1\",\n \"_version\" : 2,\n \"_seq_no\" : 1,\n \"_primary_term\" : 1,\n \"found\" : true,\n \"_source\" : {\n \"message\" : \"Hello again!\"\n }\n}<\/pre>\n\n\n\nIf you want to remove the example data, you can remove the index it was stored in.<\/p>\n\n\n\n
Delete the index<\/strong> with the command below.<\/p>\n\n\n\ncurl -X DELETE 'localhost:9200\/example'<\/pre>\n\n\n\nAll done! Elasticsearch is working great and you should have an idea of the basic queries. Feel free to test the command further to get a better grasp of the search and indexes.<\/p>\n\n\n\n
Summary<\/h2>\n\n\n\n
Congratulations! You should now have a fully working Elasticsearch node up and running. A simple single-node setup is a quick way to get started with Elasticsearch which then offers the possibility to scale up with ease. In practice, interacting with Elasticsearch works the same regardless of the number of nodes thanks to the automated rebalancing and routing.<\/p>\n\n\n\n
Elasticsearch scale effortlessly across a cluster of any size making it able to easily handle even millions of events per second. It\u2019s capable of distributing data by dividing indices into shards with optional replicas. Each node hosts one or more shards and acts as a coordinator to delegate operations to an appropriate shard.<\/p>\n","protected":false},"author":3,"featured_media":28480,"comment_status":"open","ping_status":"closed","template":"","community-category":[223],"class_list":["post-2062","tutorial","type-tutorial","status-publish","has-post-thumbnail","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/tutorial\/2062","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/tutorial"}],"about":[{"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/types\/tutorial"}],"author":[{"embeddable":true,"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/comments?post=2062"}],"version-history":[{"count":1,"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/tutorial\/2062\/revisions"}],"predecessor-version":[{"id":6447,"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/tutorial\/2062\/revisions\/6447"}],"wp:attachment":[{"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/media?parent=2062"}],"wp:term":[{"taxonomy":"community-category","embeddable":true,"href":"https:\/\/upcloud.com\/global\/wp-json\/wp\/v2\/community-category?post=2062"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}