mongodb connection pooling

Question

I am using Java driver to access mongodb. I assume the db connection pooling is internally handled by the driver.But my connection count getting increased every time I access db.

This is my serverStatus log.

"connections" : {
            "current" : 276,
            "available" : 543
    }

Do I need to explicitly close mongo connections? how should I manage connection pooling in java?

Capitally

possible duplicate of MongoDB Java Driver database connection pooling with Tomcat – Margarito

Answer 1

You should use a single Mongo object, so it will do pooling for you. However, if you do use multiple objects, you do need to call .close() explicitly.

From: http://www.mongodb.org/display/DOCS/Java+Tutorial

The Mongo class is designed to be thread safe and shared among threads. Typically you create only 1 instance for a given DB cluster and use it across your app. If for some reason you decide to create many mongo intances, note that:

all resource usage limits (max connections, etc) apply per mongo instance to dispose of an instance, make sure you call mongo.close() to clean up resources

Haloid

You should definitely avoid multiple clients for a single application. You want to minimize the total number of connections into a MongoDB deployment since each one requires almost 1MB of RAM in overhead meaning less available for cache. – Westerly

Answer 2

MongoDB, MongoDB is act as connection pool for mongoDB and it is created per application and per DB basis.

Typically you only create one MongoClient instance for a given MongoDB deployment (e.g. standalone, replica set, or a sharded cluster) and use it across your application. However, if you do create multiple instances:

All resource usage limits (e.g. max connections, etc.) apply per MongoClient instance.

Ref: http://mongodb.github.io/mongo-java-driver/3.4/driver/tutorials/connect-to-mongodb/

MongoClientOptions options = 
MongoClientOptions.builder()
            .threadsAllowedToBlockForConnectionMultiplier(prop.getThreadsAllowedToBlock())
.connectionsPerHost(pro.getConnectionsPerHost())
.connectTimeout(prop.getConnectionTimeout())
.maxWaitTime(prop.getConnectionTimeout())
.socketTimeout(1000)
.heartbeatConnectTimeout(prop.getHeartbeatConnectTimeout())
.writeConcern(WriteConcern.ACKNOWLEDGED).build();

MongoClient mongoclient = new MongoClient(seeds,credential, options); credential, options);

This is working as connection pool. We can instantiate MongoTemplate from MongoClient.

Haletky

The link you provided does not discuss connection pooling – Hardspun

Answer 3

You can set max pool size mongodb://***/?maxPoolSize=5 for detail Review this documentation https://docs.mongodb.com/manual/reference/connection-string/

Hindi