Get the number of open connections in mongoDB using java

Question

My program requires a large number of connections to be open (Mongo). I get the error :

Too many connections open, can\'t open anymore

Answer 1

You can get connection information by using the db.serverStatus() command. It has a connections subdocument which contains the total/available connections information.

For more information :

• Documentation of server status
• Details of connections block

Answer 2

Check the number of MongoDB connections using MongoDB Scala driver:

1. Create a MongoDB client:

import org.mongodb.scala._
import scala.collection.JavaConverters._
import scala.concurrent.Await
import scala.concurrent.duration._
import scala.util.{Failure, Success, Try}

// To directly connect to the default server localhost on port 27017
val mongodbClient: MongoClient = MongoClient()

// Use a Connection String
val mongodbClient: MongoClient = MongoClient("mongodb://localhost")

// or provide custom MongoClientSettings
val settings: MongoClientSettings = MongoClientSettings.builder()
    .applyToClusterSettings(b => b.hosts(List(new ServerAddress("localhost")).asJava).
    .build()
val mongodbClient: MongoClient = MongoClient(settings)

2. Call getNoOfMongodbConnection by passing mongodbClient:

val result = getNoOfMongodbConnection(mongodbClient)

3. Method to get the number of connections(current, available and total)

def getNoOfMongodbConnection(mongodbClient: MongoClient) = {

    val adminDatabase = mongodbClient.getDatabase("admin")

    val serverStatus = adminDatabase.runCommand(Document("serverStatus" -> 1)).toFuture()

    Try {
      Await.result(serverStatus, 10 seconds)

    } match {
      case Success(x) => {

        val connection = x.get("connections")
        logger.info("Number of mongodb connection:--> " + connection)
        connection
      }
      case Failure(ex) => {
        logger.error("Got error while getting the number of Mongodb connection:---> " + ex.printStackTrace())
        None
      }
    }
  }