Configuring maxSockets in Node.js

In Node.js, you can set the maximum number of connections per origin. If maxSockets is set, the low-level HTTP client queues requests and assigns them to sockets as they become available.

This lets you set an upper bound on the number of concurrent requests to a given origin at a time. Lowering this value can reduce the number of throttling or timeout errors received. However, it can also increase memory usage because requests are queued until a socket becomes available.

The following example shows how to set maxSockets for a DynamoDB client.

import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { NodeHttpHandler } from "@smithy/node-http-handler";
import https from "https";    
var agent = new https.Agent({
  maxSockets: 25
});

var dynamodbClient = new DynamoDBClient({
  requestHandler: new NodeHttpHandler({
    httpsAgent: agent
 })
});

When using the default of https, the SDK takes the maxSockets value from the globalAgent. If the maxSockets value is not defined, the SDK assumes a maxSockets value of 50.

For more information about setting maxSockets in Node.js, see the Node.js online documentation.