(function() { "use strict" ; const dbName = "test" ; const collName = "foo" ; const ns = dbName + "." + collName; const st = new ShardingTest({mongos: 2, shards: 1, verbose: 2}); let staleMongos = st.s0; let freshMongos = st.s1; jsTest.log( "Make the stale mongos load a cache entry for db " + dbName + " once" ); assert .writeOK(staleMongos.getDB(dbName).getCollection(collName).insert({_id: 1})); jsTest.log( "Call shardCollection on " + ns + " from the fresh mongos" ); assert .commandWorked(freshMongos.adminCommand({enableSharding: dbName})); assert .commandWorked(freshMongos.adminCommand({shardCollection: ns, key: { "_id" : 1 }})); jsTest.log( "Ensure the shard knows " + ns + " is sharded" ); assert .commandWorked(st.shard0.adminCommand({_flushRoutingTableCacheUpdates: ns, syncFromConfig: true })); jsTest.log( "Run explain find on " + ns + " from the stale mongos" ); // Expect the test to fail here. staleMongos.getDB(dbName).getCollection(collName).find({$query: {}, $explain: true }).next(); st.stop(); })();