title: Elasticsearch 503 error when checking server status
body: <p>I've been using elasticsearch as a search engine for my Rails application, however it stopped working properly due to a reason i can't understand. When making a curl request to elasticsearch server i get a 503 error.</p>
  
  <pre><code>curl -XGET http://localhost:9200
  {
    "ok" : true,
    "status" : 503,
    "name" : "Killpower",
    "version" : {
      "number" : "0.90.3",
      "build_hash" : "5c38d6076448b899d758f29443329571e2522410",
      "build_timestamp" : "2013-08-06T13:18:31Z",
      "build_snapshot" : false,
      "lucene_version" : "4.4"
    },
    "tagline" : "You Know, for Search"
  }
  </code></pre>
  
  <p>I've tried to solve the problem with reloading elasticsearch service and installing a new version without any success.</p>
  
  <p>Here is what I found in logs</p>
  
  <pre><code>[2013-09-03 12:31:45,320][INFO ][node                     ] [Killpower] version[0.90.3], 
  pid[4222], build[5c38d60/2013-08-06T13:18:31Z]
  [2013-09-03 12:31:45,321][INFO ][node                     ] [Killpower] initializing ...
  [2013-09-03 12:31:45,327][INFO ][plugins                  ] [Killpower] loaded [], sites []
  [2013-09-03 12:31:47,248][INFO ][node                     ] [Killpower] initialized
  [2013-09-03 12:31:47,248][INFO ][node                     ] [Killpower] starting ...
  [2013-09-03 12:31:47,313][INFO ][transport                ] [Killpower] bound_address {inet[/0:0:0:0:0:0:0:0:9300]}, publish_address {inet[/172.20.46.32:9300]}
  [2013-09-03 12:31:51,443][INFO ][discovery.zen            ] [Killpower] master_left [[Amphibion][IMB4uACSTyOx3MO2u-FsWg][inet[/fe80:0:0:0:52e5:49ff:fec2:9718%2:9300]]], reason [do not exists on master, act as master failure]
  [2013-09-03 12:31:51,446][INFO ][discovery                ] [Killpower] elasticsearch/iavpGrMtRHmWLHMTNpscGQ
  [2013-09-03 12:31:51,483][INFO ][http                     ] [Killpower] bound_address {inet[/0:0:0:0:0:0:0:0:9200]}, publish_address {inet[/172.20.46.32:9200]}
  [2013-09-03 12:31:51,484][INFO ][node                     ] [Killpower] started
  [2013-09-03 12:31:54,712][WARN ][transport.netty          ] [Killpower] exception caught on transport layer [[id: 0xa929f24d, /127.0.0.1:50456 =&gt; /127.0.0.1:9300]], closing connection
  </code></pre>
  
  <p>After that also follows a long java stacktrace. How can i fix the problem?</p>