MongoDB Connection Pooling - Mongo Pool
New features in 1.4.0
- Dynamic Expansion and Maintenance of Connection Pools
NEWConnection pools can dynamically expand when faced with high demand. Unused connections within a specified period are automatically removed, and the pool size is reduced to the specified minimum when connections are not reused within that timeframe.
Introduction
This package is a simple connection pooling for MongoDB. It is based on the mongo_dart package.
Features
- Dynamic expansion and maintenance of connection pools.
NEW - Connection pool size configuration
- Automatic connection pool expansion
- Instance where you can access the connection from the pool
- Connection lifetime configuration
- Connection leak detection
Getting started
Using this package, your application will open as many database connections as you specify as soon as it runs. You can open, close and change the number of these links at any time.
Usage
With mongodb package, you can use the MongoDbPoolService class to create a pool of connections.
First, you need to create a MongoDbPoolService instance. You can do this by passing the number of
connections you want
Next, you need to open the pool. You can do this by calling the open() method. If you want to
close the pool, you can
call the close() method.
MongoDbPoolService class has a getInstance() method. You can use this method to get the instance
of the pool.
You can use this instance to access the pool from anywhere in the project.
A simple usage example:
import 'package:mongo_pool/mongo_pool.dart';
Future<void> main() async {
/// Create a pool of 5 connections
final MongoDbPoolService poolService = MongoDbPoolService(
const MongoPoolConfiguration(
/// [maxLifetimeMilliseconds] is the maximum lifetime of a connection in the pool.
/// Connection pools can dynamically expand when faced with high demand. Unused
/// connections within a specified period are automatically removed, and the pool
/// size is reduced to the specified minimum when connections (poolSize) are not reused within
/// that timeframe.
maxLifetimeMilliseconds: 180000,
/// [leakDetectionThreshold] is the threshold for connection leak detection.
/// If the connection is not released within the specified time, it is
/// considered as a leak.
/// It won't work if no value is set. It is recommended to set a value
leakDetectionThreshold: 10000,
uriString: 'mongodb://localhost:27017/my_database',
/// [poolSize] is the minimum number of connections in the pool.
poolSize: 2,
secure: false,
tlsAllowInvalidCertificates: false,
tlsCAFile: 'path/to/ca/file',
tlsCertificateKeyFile: 'path/to/certificate/key/file',
tlsCertificateKeyFilePassword: 'password',
),
);
/// Open the pool
await initialize(poolService);
/// Get a connection from pool
final Db connection = await poolService.acquire();
// Database operations
final DbCollection collection = connection.collection('my_collection');
final List<Map<String, dynamic>> result = await collection.find().toList();
result;
// Connection release for other operations
poolService.release(connection);
// Pool close
await poolService.close();
}
Future<void> initialize(MongoDbPoolService service) async {
try {
await service.initialize();
} on Exception catch (e) {
/// handle the exception here
print(e);
}
}
class OtherClass {
OtherClass();
Future<void> initialize() async {
/// Get the instance of the pool
final MongoDbPoolService poolService = MongoDbPoolService.getInstance();
final Db connection = await poolService.acquire();
// Database operations
final DbCollection collection = connection.collection('my_collection');
final List<Map<String, dynamic>> result = await collection.find().toList();
result;
// Connection release for other operations
poolService.release(connection);
// Pool close
await poolService.close();
}
}
Testing
To run the tests, you need to have a MongoDB instance running on your machine. You can use the following command to start a MongoDB instance using Docker:
docker run -d -p 27017:27017 --name mongo mongo
Problems Solved
xMongodb srv connection problem solvedxFixed a bug that prevented a new connection from being created when no connection remainedxUnable to connect to MongoDB using SSL/TLS fixed
