Six test cases are failing frequently from AUG 30 builds under Vtn Pathmap Pathpolicy

The above failure is in the below link of jenkins releng,
https://logs.opendaylight.org/releng/jenkins092/vtn-csit-1node-manager-all-nitrogen/123/log.html.gz#s1-s1-s8

karaf.log for the above failure is in below link,
https://logs.opendaylight.org/releng/jenkins092/vtn-csit-1node-manager-all-nitrogen/123/odl1_karaf.log.gz

when connection flapping happens, observed in karaf logs there are WARN messages

2017-08-30 07:58:05,563 | WARN | ntLoopGroup-11-6 | HandshakeListenerImpl | 285 - org.opendaylight.openflowplugin.impl - 0.5.0.SNAPSHOT | initial processing failed for device openflow:1
java.lang.NullPointerException
at org.opendaylight.openflowplugin.impl.lifecycle.ContextChainHolderImpl.deviceConnected(ContextChainHolderImpl.java:150)[285:org.opendaylight.openflowplugin.impl:0.5.0.SNAPSHOT]
at org.opendaylight.openflowplugin.impl.connection.listener.HandshakeListenerImpl$1.onSuccess(HandshakeListenerImpl.java:75)[285:org.opendaylight.openflowplugin.impl:0.5.0.SNAPSHOT]
at org.opendaylight.openflowplugin.impl.connection.listener.HandshakeListenerImpl$1.onSuccess(HandshakeListenerImpl.java:68)[285:org.opendaylight.openflowplugin.impl:0.5.0.SNAPSHOT]
at com.google.common.util.concurrent.Futures$CallbackListener.run(Futures.java:1237)[27:com.google.guava:22.0.0]
at com.google.common.util.concurrent.MoreExecutors$DirectExecutor.execute(MoreExecutors.java:399)[27:com.google.guava:22.0.0]
at com.google.common.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:911)[27:com.google.guava:22.0.0]
at com.google.common.util.concurrent.AbstractFuture.complete(AbstractFuture.java:822)[27:com.google.guava:22.0.0]
at com.google.common.util.concurrent.AbstractFuture.set(AbstractFuture.java:664)[27:com.google.guava:22.0.0]
at com.google.common.util.concurrent.SettableFuture.set(SettableFuture.java:48)[27:com.google.guava:22.0.0]
at org.opendaylight.openflowjava.protocol.impl.core.connection.AbstractRpcListener.successfulRpc(AbstractRpcListener.java:88)[291:org.opendaylight.openflowplugin.openflowjava.openflow-protocol-impl:0.5.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ResponseExpectedRpcListener.completed(ResponseExpectedRpcListener.java:38)[291:org.opendaylight.openflowplugin.openflowjava.openflow-protocol-impl:0.5.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ConnectionAdapterImpl.consumeDeviceMessage(ConnectionAdapterImpl.java:149)[291:org.opendaylight.openflowplugin.openflowjava.openflow-protocol-impl:0.5.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.AbstractConnectionAdapterStatistics.consume(AbstractConnectionAdapterStatistics.java:66)[291:org.opendaylight.openflowplugin.openflowjava.openflow-protocol-impl:0.5.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.connection.ConnectionAdapterImpl.consume(ConnectionAdapterImpl.java:44)[291:org.opendaylight.openflowplugin.openflowjava.openflow-protocol-impl:0.5.0.SNAPSHOT]
at org.opendaylight.openflowjava.protocol.impl.core.DelegatingInboundHandler.channelRead(DelegatingInboundHandler.java:43)[291:org.opendaylight.openflowplugin.openflowjava.openflow-protocol-impl:0.5.0.SNAPSHOT]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341)[55:io.netty.transport:4.1.8.Final]
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102)[50:io.netty.codec:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341)[55:io.netty.transport:4.1.8.Final]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:293)[50:io.netty.codec:4.1.8.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:267)[50:io.netty.codec:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341)[55:io.netty.transport:4.1.8.Final]
at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:293)[50:io.netty.codec:4.1.8.Final]
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:267)[50:io.netty.codec:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341)[55:io.netty.transport:4.1.8.Final]
at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:287)[53:io.netty.handler:4.1.8.Final]
at org.opendaylight.openflowjava.protocol.impl.core.IdleHandler.channelRead(IdleHandler.java:39)[291:org.opendaylight.openflowplugin.openflowjava.openflow-protocol-impl:0.5.0.SNAPSHOT]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:341)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:349)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926)[55:io.netty.transport:4.1.8.Final]
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:1018)[56:io.netty.transport-native-epoll:4.1.8.Final]
at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:394)[56:io.netty.transport-native-epoll:4.1.8.Final]
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:288)[56:io.netty.transport-native-epoll:4.1.8.Final]
at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)[52:io.netty.common:4.1.8.Final]
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)[52:io.netty.common:4.1.8.Final]
at java.lang.Thread.run(Thread.java:748)[:1.8.0_141]

under model dumps operational/vtn-inventory:vtn-nodes

there are no nodes present
{
"vtn-nodes": {}
}