This happened in our cluster,
>> Standby NN was keep doing checkpoint every one hour and uploading to Active NN was continuously failing due to some kerberos issue and nobody noticed this, since Active was servicing properly.
>> Active NN was up for long time with fsimage having very least transaction.
>> Standby NN has saved the checkpoint in its name dir and purged the txns > 1000000 from shared storage ( includes edits which are not present in Active NN's fsimage)
>> After some time Active NN is restarted and StandBy NN switched to Active.
Now current Standby not able to load any edits from shared storage, as expected edits are not present in shared storage. Its keep running idle.
So editLog.purgeLogsOlderThan(purgeLogsFrom); always should be called from Active NameNode.