What happened?

Since updating to version 4.35.0-20250909, the distribution of browsers across individual nodes no longer appears to be working correctly.

My setup:

1 server running the Selenium Grid

3 servers, each hosting 30 browsers

Docker Compose files:
Grid:
services: selenium-hub: image: selenium/hub:4.35.0-20250909 container_name: selenium-hub volumes: - ./config.toml:/opt/selenium/config.toml ports: - "4442:4442" - "4443:4443" - "4444:4444" restart: always

Nodes:
services: chrome: image: selenium/node-chrome:4.35.0-20250909 container_name: selenium-chrome volumes: - /dev/shm:/dev/shm shm_size: '2gb' ports: - "10.10.0.11:5555:5555" environment: - SCREEN_WIDTH=1920 - SCREEN_HEIGHT=1080 - SE_NODE_MAX_SESSIONS=30 - SE_NODE_OVERRIDE_MAX_SESSIONS=true - SE_EVENT_BUS_HOST=10.10.0.1 - SE_EVENT_BUS_PUBLISH_PORT=4442 - SE_EVENT_BUS_SUBSCRIBE_PORT=4443 - SE_NODE_HOST=10.10.0.11 - SE_NODE_SESSION_TIMEOUT=700 restart: always

Under version 4.34.0-20250707, the distribution was clean and balanced across nodes.

Since version 4.35.0-20250909, the situation has changed — browsers are now jumping from server to server unexpectedly.

Command used to start Selenium Grid with Docker (or Kubernetes)

services:
  selenium-hub:
    image: selenium/hub:4.35.0-20250909
    container_name: selenium-hub
    volumes:
      - ./config.toml:/opt/selenium/config.toml
    ports:
      - "4442:4442"
      - "4443:4443"
      - "4444:4444"
    restart: always

Relevant log output

Operating System

Linux server

Docker Selenium version (image tag)

4.35.0-20250909

Selenium Grid chart version (chart version)

No response