# Upgrading elastic search 0.9 to 2.3.4 **URL:** \ **Category:** Elasticsearch\ **Created:** [July 13, 2016, 8:26am UTC](https://discuss.elastic.co/t/upgrading-elastic-search-0-9-to-2-3-4/55383 "2016-07-13T08:26:32Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Aviad\_Sharfshtein](https://avatars.discourse-cdn.com/v4/letter/a/71c47a/32.png) [@Aviad\_Sharfshtein](https://discuss.elastic.co/u/Aviad_Sharfshtein)\ **Post date:** [July 13, 2016, 8:26am UTC](https://discuss.elastic.co/t/upgrading-elastic-search-0-9-to-2-3-4/55383/1 "2016-07-13T08:26:32Z")
I have an old production cluster running 0.9 with JVM1.6 i'm trying to upgrade it to 2.3.4, so I've started a new machine with Jre 1.7, and started elastic. I see it is looking for other machines, but doesn't seem to be able to connect. when it is trying to connect I see the following: [2016-07-13 08:16:43,054][TRACE][transport.tracer] [elastic164] [1625][internal:discovery/zen/unicast] received response from [{#zen\_unicast\_19395\_#cloud-i-914dae0e-0#}{10.168.73.88}{10.168.73.88:9300}] [2016-07-13 08:16:43,054][WARN][transport.netty] [elastic164] exception caught on transport layer [[id: 0xf027939d, /10.147.41.201:46109 =\> /10.168.73.88:9300]], closing connection java.lang.NullPointerException at org.elasticsearch.transport.netty.MessageChannelHandler.handleException(MessageChannelHandler.java:207) at org.elasticsearch.transport.netty.MessageChannelHandler.handlerResponseError(MessageChannelHandler.java:202) at org.elasticsearch.transport.netty.MessageChannelHandler.messageReceived(MessageChannelHandler.java:136) at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70) at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564) at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:791) at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:296) at org.jboss.netty.handler.codec.frame.FrameDecoder.unfoldAndFireMessageReceived(FrameDecoder.java:462) at org.jboss.netty.handler.codec.frame.FrameDecoder.callDecode(FrameDecoder.java:443) at org.jboss.netty.handler.codec.frame.FrameDecoder.messageReceived(FrameDecoder.java:303) at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:70) at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564) at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:559) at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:268) at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:255) at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:88) at org.jboss.netty.channel.socket.nio.AbstractNioWorker.process(AbstractNioWorker.java:108) at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:337) at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:89) at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:178) at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108) at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:42) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) thanks. ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [July 13, 2016, 8:29am UTC](https://discuss.elastic.co/t/upgrading-elastic-search-0-9-to-2-3-4/55383/2 "2016-07-13T08:29:18Z")
0.9 or 0.90? However you cannot jump directly from 0.X to 2.X, you need to go to 1.X first due to Lucene changes. Also, please read the breaking changes for 2.X - [https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking-changes-2.0.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking-changes-2.0.html). Specifically, see the second set for the problem you are having. ---
**Author:** ![dadoonet](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dadoonet/32/137187_2.png) [@dadoonet](https://discuss.elastic.co/u/dadoonet)\ **Post date:** [July 13, 2016, 8:40am UTC](https://discuss.elastic.co/t/upgrading-elastic-search-0-9-to-2-3-4/55383/3 "2016-07-13T08:40:30Z")
Are you trying to connect your 1.7 node to elasticsearch 0.90 node? ---
**Author:** ![Aviad\_Sharfshtein](https://avatars.discourse-cdn.com/v4/letter/a/71c47a/32.png) [@Aviad\_Sharfshtein](https://discuss.elastic.co/u/Aviad_Sharfshtein)\ **Post date:** [July 13, 2016, 12:02pm UTC](https://discuss.elastic.co/t/upgrading-elastic-search-0-9-to-2-3-4/55383/4 "2016-07-13T12:02:55Z")
oh. ok. i'll try that. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 5, 2017, 10:36pm UTC](https://discuss.elastic.co/t/upgrading-elastic-search-0-9-to-2-3-4/55383/5 "2017-07-05T22:36:05Z")