General order for recommendation upgrades as:
- Secondaries of your shards first
- Upgrade your Primaries (using step down)
- Config servers: Take one out, upgrade it, bring it back in, repeat the process with the rest, etc Mongos processes
Question: Which of the following are REQUIRED when upgrading a sharded cluster to MongoDB 2.6? Check all that apply.
a. If your MongoDB deployment is not already running MongoDB 2.4, upgrade to 2.4 first.
b. Upgrade all mongos instances before upgrading mongod instances.
c. Upgrade all mongod instances before upgrading mongos instances.
d. Disable the balancer.
e. Upgrade the secondaries on all shards before upgrading any primary.
Ans: a, b and d