MongoError: not master and slaveOk=false at Connection. (/sv_local/npm/node_modules/mongodb/lib/core/connection/pool.js:453:61) at Connection.emit (events.js:189:13) at Connection.EventEmitter.emit (domain.js:441:20) at processMessage (/sv_local/npm/node_modules/mongodb/lib/core/connection/connection.js:456:10) at TLSSocket. (/sv_local/npm/node_modules/mongodb/lib/core/connection/connection.js:625:15) at TLSSocket.emit (events.js:189:13) at TLSSocket.EventEmitter.emit (domain.js:441:20) at addChunk (_stream_readable.js:284:12) at readableAddChunk (_stream_readable.js:265:11) at TLSSocket.Readable.push (_stream_readable.js:220:10)