How to specify which node is being queried in Mongo ReplicaSet?

Question

connection:

client = MongoClient(
    'localhost:27017',
    replicaSet='foo',
    readPreference='secondaryPreferred')

so, how to specify whether slave or master is used ? thanks~

Answer 1

You can set readPreference to either primary or secondary if you want to limit to the specific category. If need more granular control you can use tagSet to limit the options.

To use the tag sets you have to:

• Configure Replica Set Tag Sets
• perform query using specific readPref based on tag or use setReadPref on Mongo connection