Given:

• A mongodb replica set that has no primary (e.g. the majority went down)
• Node client with Replica set connection (replicaSet=rs0)
• Node client options: readPreference: ReadPreference.NEAREST, connectWithNoPrimary: true

Then I expect that I can execute query operations like db.collection() and find(). Also I want to use the collection() strict mode in orde to determine if a collection is empty or does not exist.

Behaviour:

• db.collection(strict: true) gives:

  Collection error:  TypeError: Cannot read property 'command' of undefined
      at nextFunction (/nfs/home/hidden/DataCollecties/node_modules/mongodb/node_modules/mongodb-core/lib/cursor.js:568:51)
      at Cursor.next [as _next] (/nfs/home/hidden/DataCollecties/node_modules/mongodb/node_modules/mongodb-core/lib/cursor.js:692:3)
      at fetchDocs (/nfs/home/hidden/DataCollecties/node_modules/mongodb/lib/cursor.js:856:10)
      at toArray (/nfs/home/hidden/DataCollecties/node_modules/mongodb/lib/cursor.js:883:3)
      at Cursor.toArray (/nfs/home/hidden/DataCollecties/node_modules/mongodb/lib/cursor.js:836:44)
      at Db.collection (/nfs/home/hidden/DataCollecties/node_modules/mongodb/lib/db.js:473:37)
      at /nfs/home/hidden/DataCollecties/testquerynoprimary.js:14:8
      at connectCallback (/nfs/home/hidden/DataCollecties/node_modules/mongodb/lib/mongo_client.js:428:5)
      at /nfs/home/hidden/DataCollecties/node_modules/mongodb/lib/mongo_client.js:347:11
      at nextTickCallbackWith0Args (node.js:419:9)
  

Sample nodejs program attached.
Usage:

1. Prepare 2 mongod processes, running on ports 29000 and 29001.
2. Initiate a replication set "rs0"
3. Kill one of the mongod processes, effectively making the remaining instance a Secondary.
4. Run testquerynoprimary.js as given below:

$ set MONGO_CONNECTION_STRING=mongodb://localhost:29000,localhost:29001/myDb?replicaSet=rs0

$ MONGO_STRICT=false node testquerynoprimary.js
Using: mongodb://localhost:29000,localhost:29001/myDb?replicaSet=rs0 false
Find OK: size:  0

$ MONGO_STRICT=true node testquerynoprimary.js
Using: mongodb://localhost:29000,localhost:29001/myDb?replicaSet=rs0 true
Collection error:  .... etc ....