PCEP request occasionally not found in outstanding DB

When doing performance test, sometimes the situation described by the following log fragments happens, during add-lsp:

2014-07-18 03:40:04.005 PDT [nettyThreadgroupModule$NioEventLoopGroupCloseable-7-4]
TRACE o.o.p.pcep.impl.PCEPSessionImpl - Message sent to socket: Pcinitiate [_pcinitiateMessage=PcinitiateMessage [_requests=[Requests [_srp=Srp [_operationId=SrpIdNumber [_value=1], ...

2014-07-18 03:40:04.007 PDT [nettyThreadgroupModule$NioEventLoopGroupCloseable-7-4] DEBUG o.o.p.pcep.impl.PCEPSessionImpl - PCEP message Pcrpt [_pcrptMessage=PcrptMessage [_reports=[Reports [ ... _srp=Srp [_operationId=SrpIdNumber [_value=1], ...

2014-07-18 03:40:04.007 PDT [nettyThreadgroupModule$NioEventLoopGroupCloseable-7-4] WARN o.o.b.p.t.p.Stateful07TopologySessionListener - Request ID SrpIdNumber [_value=1] not found in outstanding DB

This results in add-lsp never returning any output.