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HOMEWORK: HOMEWORK 6.4 You have a sharded system with three shards and have sharded the collections "students" in the "school" database across those shards. The output of sh.status() when connected to mongos looks like this: mongos> sh.status() --- Sharding Status --- sharding version: { "_id" : 1, "minCompatibleVersion" : 5, "currentVersion" : 6, "clusterId" : ObjectId("5531512ac723271f602db407") } shards: { "_id" : "s0", "host" : "s0/localhost:37017,localhost:37018,localhost:37019" } { "_id" : "s1", "host" : "s1/localhost:47017,localhost:47018,localhost:47019" } { "_id" : "s2", "host" : "s2/localhost:57017,localhost:57018,localhost:57019" } balancer: Currently enabled: yes Currently running: yes Balancer lock taken at Fri Apr 17 2015 14:32:02 GMT-0400 (EDT) by ed

HOMEWORK: HOMEWORK 6.3 Which of the following statements are true about choosing and using a shard key? There must be a index on the collection that starts with the shard key. Any update that does not contain the shard key will be sent to all shards. The shard key must be unique MongoDB can not enforce unique indexes on a sharded collection other than the shard key itself, or indexes prefixed by the shard key. You can change the shard key on a collection if you desire.

HOMEWORK: HOMEWORK 6.2 Let's suppose you have a five member replica set and want to assure that writes are committed to the journal and are acknowledged by at least 3 nodes before you proceed forward. What would be the appropriate settings for w and j? w=1, j=1 w="majority", j=1 w=3, j=0 w=5, j=1 w=1,j=3

HOMEWORK: HOMEWORK 6.1 Which of the following statements are true about replication in MongoDB? Check all that apply. The minimum sensible number of voting nodes to a replica set is three. MongoDB replication is synchronous. By default, using the new MongoClient connection class, w=1 and j=1. The oplog utilizes a capped collection.