In this chapter, you were shown how to monitor replica set status and were given tips on factors to watch that might indicate a potential performance problem. Aspects covered in this section included managing the size of the oplog and viewing the overall replica set status.
You were also shown how to back up and restore a replica set, as well as how to resynchronize a replica set member.
You then learned that the application program code does not need to change when addressing a replica set. You were shown how to enhance your applications to take advantage of a replica set in terms of failover, directing preferences for read operations, and ensuring data integrity by manipulating write concerns.
In the next chapter, we will show you how to scale your database horizontally by implementing a sharded cluster.
