if you are getting SERVICE_UNAVAILABLE error after endorsing the transaction, in raft orderering service if there is no leader elected. check any of the active orderering node logs it would be like below: 2019-11-20 10:08:07.345 UTC [orderer.consensus.etcdraft] serveRequest -> WARN 18d No leader is present, cluster size is 2 channel=chheader node=2 Error: Failed to send transaction successfully to the orderer status:SERVICE_UNAVAILABLE.
make sure there is always leader oderer available.