Node.js http2session.state Method

Last Updated : 17 Aug, 2026

Node.js http2session.state is a property that provides information about the current internal state of an HTTP/2 session. It is useful for monitoring session behavior and understanding how the connection is performing at runtime.

  • It provides information such as the number of active streams and pending settings.
  • It helps developers monitor and debug HTTP/2 session activity.
  • It is accessed from an active Http2Session instance.

Syntax:

http2session.state

Where

  • http2session : It represents an active Http2Session instance in Node.js.
  • state : It is a property of the session that provides an object describing the current internal state.

Return Value: It returns an object containing the current HTTP/2 session state.

Example 1:

javascript 
const http2 = require('http2');
const fs = require('fs');

// Private key and public certificate
// for access
const options = {
    key: fs.readFileSync('private-key.pem'),
    cert: fs.readFileSync('public-cert.pem'),
};

// Creating and initializing server
// by using http2.createServer() method
const server = http2.createServer(options);

server.on('stream', (stream, requestHeaders) => {
    stream.respond({ 
        ':status': 200, 
        'content-type': 'text/plain' 
    });
    
    stream.write('hello ');

    const http2session = stream.session;

    // Getting state associated with this 
    // session by using state method
    const status = http2session.state;

    stream.end("local window size : " 
        + status.localWindowSize);

    // Stopping the server
    // by using the close() method
    server.close(() => {
        console.log("server localSettings");
    })
});

server.listen(8000);

// Creating and initializing client
// by using tls.connect() method
const client = http2.connect(
        'http://localhost:8000');

const req = client.request({ 
    ':method': 'GET', 
    ':path': '/' 
});

req.on('response', (responseHeaders) => {
    console.log("status : " 
        + responseHeaders[":status"]);
});

req.on('data', (data) => {
    console.log('Received: %s ',
        data.toString().replace(/(\n)/gm, ""));
});

req.on('end', () => {
    client.close(() => {
        console.log("client localSettings");
    })
});

Output

status : 200
Received: hello
Received: local window size : 65535
client localSettings
server localSettings

Example 2:

javascript 
const http2 = require('http2');
const fs = require('fs');

// Private key and public certificate
// for access
const options = {
    key: fs.readFileSync('private-key.pem'),
    cert: fs.readFileSync('public-cert.pem'),
};

// Creating and initializing server
// by using http2.createServer() method
const server = http2.createServer(options);

server.on('stream', (stream, requestHeaders) => {

    // Getting session object
    // by using session method
    const http2session = stream.session;

    // Getting state associated with this
    // session by using state method
    const status = http2session.state;

    stream.end("numeric id of recent data : " 
            + status.lastProcStreamID);

    // Stopping the server
    // by using the close() method
    server.close(() => {
        console.log("server destroyed");
    })
});

server.listen(8000);

// Creating and initializing client
// by using tls.connect() method
const client = http2.connect(
        'http://localhost:8000');

const req = client.request({ 
    ':method': 'GET', 
    ':path': '/' 
});

req.on('data', (data) => {
    console.log('Received: %s ',
        data.toString().replace(/(\n)/gm, ""));
});

req.on('end', () => {
    client.close(() => {
        console.log("client destroyed");
    })
});

Output

Received: numeric id of recent data : 1
client destroyed
server destroyed

Use Cases of http2session.state Method

  • It is used to monitor the current state of an HTTP/2 session.
  • It helps in debugging session-related issues.
  • It is useful for tracking stream activity and session metrics.
  • It assists in managing and optimizing HTTP/2 connections.

Reference: https://nodejs.org/dist/latest-v12.x/docs/api/http2.html#http2_http2session_state

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