CODEWITHSUNDEEP
javaspringmongodbconnection
Abhilash PS
Abhilash PS

Reputation: 794

Too many connections error while using mongodb with java

I use MongoDbFactory to connect to mongodb with Java. But the mongo service throws socket exception at least once every hour. Hence I am forced to restart mongodb service to restore operations. I think that this may be a result of unclosed connections to mongodb from java and also MongoDbFactory do not provide me a function to close a connection. How can I make sure that all connections are closed after a particular session.

This is the code I am using:

package com.####.mongo.configuration;

import com.mongodb.Mongo;
import org.springframework.context.annotation.Bean;
import org.springframework.data.mongodb.MongoDbFactory;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.mongodb.core.SimpleMongoDbFactory;
import org.springframework.data.mongodb.core.convert.DefaultMongoTypeMapper;
import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
import org.springframework.data.mongodb.core.mapping.MongoMappingContext;

@Configuration
public class SpringMongoFeedConfig {

public @Bean
MongoDbFactory mongoDbFactory() throws Exception {
    return new SimpleMongoDbFactory(new Mongo(), "feedDatabase");
}

public @Bean
MongoTemplate mongoTemplate() throws Exception {

    MappingMongoConverter converter = new MappingMongoConverter(mongoDbFactory(), new MongoMappingContext());
    converter.setTypeMapper(new DefaultMongoTypeMapper(null));
    MongoTemplate mongoTemplate = new MongoTemplate(mongoDbFactory(), converter);


    return mongoTemplate; 
}

}

And:

private String insertFeedsToMongo(FeedMongoDTO feedObject, FeedType type) throws UnknownHostException {
    try {
        ApplicationContext ctx = new AnnotationConfigApplicationContext(SpringMongoFeedConfig.class);
        MongoOperations mongoOperation = (MongoOperations) ctx.getBean("mongoTemplate");

        switch (type) {

        case FOLLOW:
            mongoOperation.save(feedObject, "feedsByUid");
            break;

        case GENERAL:
            mongoOperation.save(feedObject, "allFeeds");
            break;

        default:
            break;
        }

        return feedObject.getId();

    } catch (Exception ex) {
        log.info("insertFeedsToMongo() : mongo Exception - ", ex);
        return null;
    }
}

Upvotes: 4

Views: 3339

Answers (2)

Abhilash PS
Abhilash PS

Reputation: 794

With akaIDIOT's suggestion I have done as following 

public class FeedMongoOperations {

public static transient Log log = LogFactory.getLog(FeedMongoOperations.class);

private Mongo mongo;
private SimpleMongoDbFactory dbFactory;
private MongoTemplate mongoTemplate;

public boolean openDbConnection() {
    try {
        MongoOptions options = new MongoOptions();
        options.connectionsPerHost = 100;
        mongo = new Mongo("localhost", options);
        dbFactory = new SimpleMongoDbFactory(mongo, "feedDatabase");
        MappingMongoConverter converter = new MappingMongoConverter(dbFactory, new MongoMappingContext());
        converter.setTypeMapper(new DefaultMongoTypeMapper(null));
        mongoTemplate = new MongoTemplate(dbFactory, converter);

        return true;
    } catch (Exception e) {
        return false;
    }
}

public boolean closeDbConnection() {
    try {
        mongoTemplate = null;
        dbFactory = null;
        mongo.close();

        return true;
    }
}

public String save(FeedMongoDTO feed, String collectionName) {
    try {
        mongoTemplate.save(feed, collectionName);
        return feed.getId();
    } catch (Exception ex) {
        return null;
    } 
}

public FeedMongoDTO getFeed(String mongoId, String collectionName) {

    try {
        FeedMongoDTO feedMongoDTO = mongoTemplate.findOne(new Query(Criteria.where("id").is(mongoId)), FeedMongoDTO.class,
                collectionName);
        return feedMongoDTO;
    } catch (Exception ex) {
        return null;
    }
}

}

Upvotes: 2

akaIDIOT
akaIDIOT

Reputation: 9231

I've encountered issues with the Mongo object as well. Making sure to call myMongo.close() when that particular connection is done resolved it.

I would suggest storing your instances created with new Mongo() in your factory function somewhere that would allow it to be closed later (the SimpleMongoDbFactory might be just the place for that). Just noted that's a Spring-thing. Suggestion remains: track your Mongo instances.

Upvotes: 2

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