Hi Anil, Make sure you're not sharing the same Connection between multiple threads as it's not thread safe. Thanks, James
On Sunday, October 2, 2016, anil gupta <anilgupt...@gmail.com> wrote: > Hi, > > We are running HDP2.3.4(HBase 1.1 and Phoenix 4.4). I have a MapReduce job > thats writing data to a very simple Phoenix table. We intermittently get > and due to this our job fails: > java.util.ConcurrentModificationException at java.util.HashMap$ > HashIterator.remove(HashMap.java:944) at org.apache.phoenix.execute. > MutationState.commit(MutationState.java:472) at org.apache.phoenix.jdbc. > PhoenixConnection$3.call(PhoenixConnection.java:461) at > org.apache.phoenix.jdbc.PhoenixConnection$3.call(PhoenixConnection.java:458) > at org.apache.phoenix.call.CallRunner.run(CallRunner.java:53) at > org.apache.phoenix.jdbc.PhoenixConnection.commit(PhoenixConnection.java:458) > at org.apache.phoenix.jdbc.PhoenixStatement$2.call(PhoenixStatement.java:308) > at org.apache.phoenix.jdbc.PhoenixStatement$2.call(PhoenixStatement.java:297) > at org.apache.phoenix.call.CallRunner.run(CallRunner.java:53) at > org.apache.phoenix.jdbc.PhoenixStatement.executeMutation(PhoenixStatement.java:295) > at org.apache.phoenix.jdbc.PhoenixPreparedStatement.executeUpdate( > PhoenixPreparedStatement.java:200) > > We are running these upserts as part of code in Mapper that executes as > part of ChainReducer. One problem i noticed that we were instantiating > PreparedStatment everytime(conn == Connection object) we were doing an > upsert : > > conn.prepareStatement(TcErrorWritable.buildUpsertNewRowStatement(TC_DOWNLOAD_ERRORS_TABLE)); > > This is the only line that seems awkward to me in that code. We have other > projects writing to Phoenix at a much higher throughput and volume of data > but we never ran into this problem. Can anyone provide me more details on > why we are getting ConcurrentModificationException while doing upserts? > > -- > Thanks & Regards, > Anil Gupta >
