Problem:
After dropping a shard and re-creating a shard with the same name, the following was seen in the logs

Sun Oct 10 20:37:43 [conn173932] DBException in process: setShardVersion failed!

{ "errmsg" : "exception: gotShardHost different than what i had before before [set3/rs3a:27018] got [set3/rs3a:27018,rs3b:27018] ", "code" : 13299, "ok" : 0 }

Reproduce:

• turn the balancer off
  db.settings.update( { _id : "balancer" }

  ,

  Unknown macro: { $set }

  , true )

• create a 2 member replset, "foo"
• add the shard with a single member
  db.runCommand( { addshard : "foo/node1", maxSize: 409600, name : "shard1" }

  );

• remove the shard
  db.runCommand( { removeshard : "foo/node1" }

  );

• add the shard again, but with both nodes
  db.runCommand( { addshard : "foo/node1,node2", maxSize: 409600, name : "shard1" }

  );

Workaround:
Since the members of the shard were part of a replset, the following was performed to clear the error

• find the current master (through looking at the rs.status()
• for the current master, do a rs.stepDown()
• restart that mongod process
• repeat until all members of the replset had been re-started

Business Case:

• Reliability
  Need to deal with stale meta-data more gracefully and automatically