Verification of Elasticsearch service

To verify of Elasticsearch service you can use following command:

• Control of the Elastisearch system service via systemd: # sysetmctl status elasticsearch output:

    `elasticsearch.service - Elasticsearch`
    `Loaded: loaded (/usr/lib/systemd/system/elasticsearch.service; enabled; vendor preset: disabled)`
    `Active: active (running) since Fri 2017-09-01 10:36:52 CEST; 3h 7min ago`
     `Docs: http://www.elastic.co`
    `Main PID: 8362 (java)`
    `CGroup: /system.slice/elasticsearch.service`
           `└─8362 /bin/java -Xms256m -Xmx1g -Djava.awt.headless=true`
  

• Control of Elasticsearch instance via tcp port:

# curl -XGET '127.0.0.1:9200/'

output:

`{`
`  "name" : "Henry Peter Gyrich",`
 ` "cluster_name" : "elasticsearch",`
  `"version" : {`
   ` "number" : "2.3.5",`
    `"build_hash" : "90f439ff60a3c0f497f91663701e64ccd01edbb4",`
    `"build_timestamp" : "2016-07-27T10:36:52Z",`
    `"build_snapshot" : false,`
    `"lucene_version" : "5.5.0"`
  `},`
  `"tagline" : "You Know, for Search"`
`}`

• Control of Elasticsearch instance via log file:

  # tail -f /var/log/elasticsearch/elasticsearch.log

• other control commands via curl application:

    `curl -xGET "http://localhost:9200/_cat/health?v"`
    `curl -XGET "http://localhost:9200/_cat/nodes?v"`
    `curl -XGET "http://localhost:9200/_cat/indicates"`