Delete transactions fail in MinMaxElementsValidation under load

In OVSDB we're seeing transaction failures from MinMaxElementsValidation under load; the log is (with the extra info from 30247 and 30249):

2015-11-26 15:40:12,794 | ERROR | lt-dispatcher-24 | LocalThreePhaseCommitCohort | 178 - org.opendaylight.controller.sal-distributed-datastore - 1.3.0.SNAPSHOT | Failed to prepare transaction member-1-chn-1-txn-38 on backend
com.google.common.base.VerifyException: Total child count is -1 (from NodeModification [identifier=(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node, modificationType=TOUCH, childModification={(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node[

{(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node-id=ovsdb://127.0.0.1:6640/bridge/br-int}

]=NodeModification [identifier=(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node[

{(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node-id=ovsdb://127.0.0.1:6640/bridge/br-int}

], modificationType=DELETE, childModification={}], (urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node[

{(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node-id=ovsdb://127.0.0.1:6640}

]=NodeModification [identifier=(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node[

{(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node-id=ovsdb://127.0.0.1:6640}

], modificationType=DELETE, childModification={}]}] and Optional.of(MaterializedContainerNode{subtreeVersion=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@7cb06828, children={(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node[

{(urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node-id=ovsdb://127.0.0.1:6640/bridge/br-int}

]=LazyContainerNode{subtreeVersion=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@398378c4, children={AugmentationIdentifier

{childNames=[(urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)controller-entry, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-external-ids, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-other-configs, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)datapath-id, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)fail-mode, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)protocol-entry, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)flow-node, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-uuid, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-name, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-openflow-node-ref, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)managed-by, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)datapath-type]}

=LazyContainerNode{subtreeVersion=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@398378c4, children={(urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-external-ids=MaterializedContainerNode{subtreeVersion=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@398378c4, children={(urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-external-ids[

{(urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-external-id-key=opendaylight-iid}

]=MaterializedContainerNode{subtreeVersion=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@398378c4, children={(urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-external-id-value=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@6e9ea50b, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-external-id-key=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@74c4f53a}}}}, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-other-configs=MaterializedContainerNode{subtreeVersion=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@398378c4, children={(urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-other-configs[

{(urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-other-config-key=disable-in-band}

]=MaterializedContainerNode{subtreeVersion=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.Version@398378c4, children={(urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-other-config-value=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@bca32a2, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-other-config-key=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@29ad2e47}}}}, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-name=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@32806084, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)fail-mode=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@613e3ecb, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)bridge-uuid=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@3b3b4f6c, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)managed-by=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@7ba4815a, (urn:opendaylight:params:xml:ns:yang:ovsdb?revision=2015-01-05)datapath-type=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@4a914aea}}, (urn:TBD:params:xml:ns:yang:network-topology?revision=2013-10-21)node-id=org.opendaylight.yangtools.yang.data.api.schema.tree.spi.ValueNode@5ac9fd15}}}}))
at com.google.common.base.Verify.verify(Verify.java:123)[79:com.google.guava:18.0.0]
at org.opendaylight.yangtools.yang.data.impl.schema.tree.MinMaxElementsValidation.checkMinMaxElements(MinMaxElementsValidation.java:86)[95:org.opendaylight.yangtools.yang-data-impl:0.8.0.SNAPSHOT]
at org.opendaylight.yangtools.yang.data.impl.schema.tree.MinMaxElementsValidation.checkTouchApplicable(MinMaxElementsValidation.java:146)[95:org.opendaylight.yangtools.yang-data-impl:0.8.0.SNAPSHOT]

Regards,

Stephen