Recovery failed

Hi team,

We are having issue with recovery where it errors out due to topology.

[133620]{-1}[-1/-1] 2014-10-20 17:29:41.192260 f NameServer       TREXNameServer.cpp(02876) : convert topology failed, no mapping defined for host <hostname>> -> stopping instance ...

[14386]{-1}[-1/-1] 2014-10-21 10:57:42.182085 e Backup           TREXNameServer.cpp(05983) : Convert topology: no mapping defined for host <hostname>>

[14386]{-1}[-1/-1] 2014-10-21 10:57:42.182655 e Backup           BackupMgr_Manager.cpp(04594) : RECOVER DATA finished with error: [110092] Recovery failed in nameserver startup: convert topology failed, no mapping defined for host <hostname>>

the topology is same across the two hosts. I am not understanding as to how to trace it .