This is happening on Nitrogen. Not sure for how long, as there were other issues hiding this.

On the robot side, this occasionally manifests [0] as observed data not matching the expected data.

Looking at the testtool log [1], the data do not match as two separate datastores are created:

12:57:03.218 [nioEventLoopGroup-2-1] DEBUG o.o.c.s.c.s.d.SnapshotBackedWriteTransaction - Write Tx: DOM-OPER-0 allocated with snapshot org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@14d698c6
12:57:03.218 [nioEventLoopGroup-2-1] DEBUG o.o.c.s.c.s.d.SnapshotBackedWriteTransaction - Write Tx: DOM-CFG-0 allocated with snapshot org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@4fea454c
12:57:03.219 [nioEventLoopGroup-2-4] DEBUG o.o.c.s.c.s.d.SnapshotBackedWriteTransaction - Write Tx: DOM-OPER-0 allocated with snapshot org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@2f6c84d4
12:57:03.222 [nioEventLoopGroup-2-4] DEBUG o.o.c.s.c.s.d.SnapshotBackedWriteTransaction - Write Tx: DOM-CFG-0 allocated with snapshot org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@44e2b43d

And the reason for that is two clients connecting to the same simulated device (testtool does not expect two clients for the same device):

12:56:55.897 [main] INFO o.o.n.t.tool.NetconfDeviceSimulator - All simulated devices started successfully from port 17830 to 17830
12:56:56.943 [sshd-netconf-ssh-server-nio-group-thread-1] DEBUG o.a.sshd.common.io.nio2.Nio2Session - Creating IoSession on /10.29.13.225:17830 from /10.29.14.155:54522
...
12:57:02.727 [sshd-netconf-ssh-server-nio-group-thread-2] DEBUG o.a.sshd.common.io.nio2.Nio2Session - Creating IoSession on /10.29.13.225:17830 from /10.29.14.155:54524

Looking at karaf.log [2], the first duplicity is:

2017-08-14 12:56:56,941 | INFO | n-dispatcher-105 | AbstractNetconfTopology | 126 - netconf-topology-config - 1.3.0.SNAPSHOT | Connecting RemoteDevice

{Uri [_value=netconf-test-device]}

, with config Node{getNodeId=Uri [_value=netconf-test-device], augmentations={interface org.opendaylight.yang.gen.v1.urn.opendaylight.netconf.node.topology.rev150114.NetconfNode=NetconfNode{getActorResponseWaitTime=5, getBetweenAttemptsTimeoutMillis=2000, getConcurrentRpcLimit=0, getConnectionTimeoutMillis=20000, getCredentials=LoginPassword{getPassword=topsecret, getUsername=admin, augmentations={}}, getDefaultRequestTimeoutMillis=60000, getHost=Host [_ipAddress=IpAddress [_ipv4Address=Ipv4Address [_value=10.29.13.225]]], getKeepaliveDelay=0, getMaxConnectionAttempts=0, getPort=PortNumber [_value=17830], getSchemaCacheDirectory=schema, getSleepFactor=1.5, isReconnectOnChangedSchema=false, isSchemaless=false, isTcpOnly=false}}}

followed by an equivalent line at 12:56:56,951 but from thread on-dispatcher-67.

[0] https://logs.opendaylight.org/releng/jenkins092/netconf-csit-1node-userfeatures-only-nitrogen/110/log.html.gz#s1-s4-s1-t15-k2-k1-k2-k1
[1] https://logs.opendaylight.org/releng/jenkins092/netconf-csit-1node-userfeatures-only-nitrogen/110/testtool--netconf-userfeatures-txt-CRUD-CRUD.log.gz
[2] https://logs.opendaylight.org/releng/jenkins092/netconf-csit-1node-userfeatures-only-nitrogen/110/odl1_karaf.log.gz