Connection Pools (original) (raw)
In this guide, you can learn about how PyMongo uses connection pools to manage connections to a MongoDB deployment and how you can configure connection pool settings in your application.
A connection pool is a cache of open database connections maintained by PyMongo. When your application requests a connection to MongoDB, PyMongo seamlessly gets a connection from the pool, performs operations, and returns the connection to the pool for reuse.
Connection pools help reduce application latency and the number of times new connections are created by PyMongo.
You can specify the following connection pool settings in your MongoClient object or in your connection URI:
| Setting | Description |
|---|---|
| connectTimeoutMS | The time that PyMongo waits when establishing a new connection before timing out.Data Type: intDefault: 20000MongoClient Example: connectTimeoutMS = 40000Connection URI Example: connectTimeoutMS=40000 |
| maxConnecting | The maximum number of connections that each pool can establish concurrently. If this limit is reached, further requests wait until a connection is established or another in-use connection is checked back into the pool.Data Type: intDefault: 2MongoClient Example: maxConnecting = 3Connection URI Example: maxConnecting=3 |
| maxIdleTimeMS | The maximum time that a connection can remain idle in the pool. When a connection exceeds this limit, PyMongo closes the connection and removes it from the pool.Data Type: intDefault: None (no limit)MongoClient Example: maxIdleTimeMS = 60000Connection URI Example: maxIdleTimeMS=60000 |
| maxPoolSize | The maximum number of concurrent connections that the pool maintains. If the maximum pool size is reached, further requests wait until a connection becomes available.Data Type: intDefault: 100MongoClient Example: maxPoolSize = 150Connection URI Example: maxPoolSize=150 |
| minPoolSize | The minimum number of concurrent connections that the pool maintains. If the number of open connections falls below this value due to network errors, PyMongo attempts to create new connections to maintain this minimum.Data Type: intDefault: 0MongoClient Example: minPoolSize = 3Connection URI Example: minPoolSize=3 |
| socketTimeoutMS | The length of time that PyMongo waits for a response from the server before timing out.Data Type: intDefault: None (no timeout)MongoClient Example: socketTimeoutMS = 100000Connection URI Example: socketTimeoutMS=100000 |
| waitQueueTimeoutMS | How long a thread waits for a connection to become available in the connection pool before timing out.Data Type: intDefault: None (no timeout)MongoClient Example: waitQueueTimeoutMS = 100000Connection URI Example: waitQueueTimeoutMS=100000 |
The following code creates a client with a maximum connection pool size of 50 by using themaxPoolSize parameter. Select the Synchronous or Asynchronoustab to see the corresponding code:
client = MongoClient(host, port, maxPoolSize=50)
client = AsyncMongoClient(host, port, maxPoolSize=50)
The following code creates a client with the same configuration as the preceding example, but uses a connection URI:
client = MongoClient(host, port, maxPoolSize=50)
client = AsyncMongoClient(host, port, maxPoolSize=50)
To learn more about connection pools, see Connection Pool Overviewin the MongoDB Server manual.
To learn more about any of the methods or types discussed in this guide, see the following API documentation: