title: Cassandra Nodes Going Down
body: <p>I have a 3 node Cassandra cluster setup (replication set to 2) with Solr installed, each node having RHEL, 32 GB Ram, 1 TB HDD and DSE 4.8.3. There are lots of writes happening on my nodes and also my web application reads from my nodes.</p>
  
  <ol>
  <li>I have observed that all the nodes go down after every 3-4 days. I have to do a restart of every node and then they function quite well till the next 3-4 days and again the same problem repeats. I checked the server logs but they do not show any error even when the server goes down. I am unable to figure out why is this happening.</li>
  <li>In my application, sometimes when I connect to the nodes through the C# Cassandra driver, I get the following error
  
  <blockquote>
    <p>Cassandra.NoHostAvailableException: None of the hosts tried for query are available (tried: 'node-ip':9042) at Cassandra.Tasks.TaskHelper.WaitToComplete(Task task, Int32 timeout) at Cassandra.Tasks.TaskHelper.WaitToComplete[T](Task``1 task, Int32 timeout) at Cassandra.ControlConnection.Init() at Cassandra.Cluster.Init()`</p>
  </blockquote></li>
  </ol>
  
  <p>But when I check the OpsCenter, none of the nodes are down. All nodes status show perfectly fine. Could this be a problem with the driver? Earlier I was using Cassandra C# driver version 2.5.0 installed from nuget, but now I updated even that to version 3.0.3 still this errors persists.</p>
  
  <p>Any help on this would be appreciated. Thanks in advance.</p>