title: Caused by: org.apache.solr.common.SolrException: Index locked for write for core
body: <p>We are using solr4.3 with master/slave setup, today I got the following error and solr stopped responding. What could be causing this,</p>
  
  <pre><code> Caused by: org.apache.solr.common.SolrException: Index locked for write for core XXX
      at org.apache.solr.core.SolrCore.&lt;init&gt;(SolrCore.java:821)
      at org.apache.solr.core.SolrCore.&lt;init&gt;(SolrCore.java:618)
      at org.apache.solr.core.CoreContainer.createFromLocal(CoreContainer.java:949)
      at org.apache.solr.core.CoreContainer.create(CoreContainer.java:984)
      at org.apache.solr.core.CoreContainer$2.call(CoreContainer.java:597)
      at org.apache.solr.core.CoreContainer$2.call(CoreContainer.java:592)
      at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
      at java.util.concurrent.FutureTask.run(FutureTask.java:138)
      at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439)
      at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
      at java.util.concurrent.FutureTask.run(FutureTask.java:138)
      at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
      ... 1 more
  Caused by: org.apache.lucene.store.LockObtainFailedException: Index locked for write for core XX        at org.apache.solr.core.SolrCore.initIndex(SolrCore.java:484)
      at org.apache.solr.core.SolrCore.&lt;init&gt;(SolrCore.java:745)
      ... 13 more
  </code></pre>