Timeout error when connecting from app server

Hello, We have setup the couchbase cluster where we have configured 3 nodes for data, 2 nodes for query and other nodes for the rest of the services. In the microservice connection string , connection is happening to the data service nodes on port 11210/11207. However we are seeing the connection timeout errors for crud operations from app servers. Is there anything particular we need to look at or any timeout settings need to be modified.