Technical blog post for Selenium Grid 4.41.0

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Description

Technical blog post for Selenium Grid 4.41.0

Motivation and Context

Types of changes

• Change to the site (I have double-checked the Netlify deployment, and my changes look good)
• Code example added (and I also added the example to all translated languages)
• Improved translation
• Added new translation (and I also added a notice to each document missing translation)

Checklist

• I have read the contributing document.
• I have used hugo to render the site/docs locally and I am sure it works.

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PR Type

Documentation

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Description

• Comprehensive blog post documenting Selenium Grid 4.41.0 release features

• Covers Dynamic Grid for Kubernetes, Session Event API, and event-driven video recording

• Details Distributor reliability fixes, Traefik ingress migration, and browser version matrix

• Includes upgrade instructions and references to all related PRs and commits

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Diagram Walkthrough

flowchart LR
  A["Selenium Grid 4.41.0"] --> B["Dynamic Grid<br/>Kubernetes"]
  A --> C["Session Event API"]
  A --> D["Event-Driven<br/>Video Recording"]
  A --> E["Traefik Ingress<br/>Migration"]
  A --> F["Distributor<br/>Reliability Fixes"]
  A --> G["Browser Version<br/>Matrix"]
  B --> B1["KubernetesSessionFactory"]
  B --> B2["NodeKubernetes Image"]
  C --> C1["Client-to-Grid Events"]
  C --> C2["ZeroMQ Sidecar"]
  D --> D1["Session Lifecycle Tracking"]
  D --> D2["Failure-Only Upload"]
  F --> F1["Thread Exhaustion Fix"]
  F --> F2["WebSocket Leak Fix"]
  F --> F3["Deadlock Prevention"]

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File Walkthrough

Relevant files

Documentation

selenium-grid-4-41-deep-dive.md Selenium Grid 4.41.0 release announcement and technical deep dive website_and_docs/content/blog/2026/selenium-grid-4-41-deep-dive.md New comprehensive blog post documenting Selenium Grid 4.41.0 release highlights Detailed explanation of Dynamic Grid native Kubernetes support with KubernetesSessionFactory Session Event API documentation with multi-language client examples and ZeroMQ sidecar consumption Event-driven video recording improvements and selective upload based on test failure status Traefik ingress controller migration guide replacing deprecated Ingress NGINX Distributor reliability fixes addressing thread exhaustion, WebSocket leaks, and deadlock scenarios Browser version matrix overview with 167+ image variants and interactive debugging features Upgrade instructions for Docker Compose, Helm, and standalone JAR deployments Complete reference table of all related PRs and commits across Selenium and docker-selenium repositories +625/-0

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[qodo-code-review]

PR Compliance Guide 🔍

Below is a summary of compliance checks for this PR:

Security Compliance

⚪

Event bus exposure Description: The post encourages exposing the ZeroMQ event bus on all interfaces via --publish-events "tcp://:4442" and --subscribe-events "tcp://:4443", which could enable unauthorized event subscription/injection if those ports are reachable outside a trusted network segment (no auth/TLS is mentioned). selenium-grid-4-41-deep-dive.md [291-301] Referred Code This is not limited to Hub+Node setups. **Standalone** can expose the same publish and subscribe ports so any sidecar can tap into the event bus alongside it: ```bash java -jar selenium-server.jar standalone \ --bind-bus true \ --events-implementation "org.openqa.selenium.events.zeromq.ZeroMqEventBus" \ --publish-events "tcp://*:4442" \ --subscribe-events "tcp://*:4443" With --bind-bus true, Standalone starts its own ZeroMQ event bus and exposes it on the configured ports — the same ports your sidecar would connect to for subscriptions. This makes it straightforward to build any sidecar that reacts to lifecycle events and custom test signals through a single subscription, regardless of whether you are running a full Grid cluster or a single Standalone container. </details></details></td></tr> <tr><td colspan='2'><strong>Ticket Compliance</strong></td></tr> <tr><td>⚪</td><td><details><summary>🎫 <strong>No ticket provided </strong></summary> - [ ] Create ticket/issue <!-- /create_ticket --create_ticket=true --> </details></td></tr> <tr><td colspan='2'><strong>Codebase Duplication Compliance</strong></td></tr> <tr><td>⚪</td><td><details><summary><strong>Codebase context is not defined </strong></summary> Follow the <a href='https://qodo-merge-docs.qodo.ai/core-abilities/rag_context_enrichment/'>guide</a> to enable codebase context checks. </details></td></tr> <tr><td colspan='2'><strong>Custom Compliance</strong></td></tr> <tr><td rowspan=6>🟢</td><td> <details><summary><strong>Generic: Comprehensive Audit Trails</strong></summary><br> **Objective:** To create a detailed and reliable record of critical system actions for security analysis <br>and compliance.<br> **Status:** Passed<br> > Learn more about managing compliance <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#configuration-options'>generic rules</a> or creating your own <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#custom-compliance'>custom rules</a> </details></td></tr> <tr><td> <details><summary><strong>Generic: Meaningful Naming and Self-Documenting Code</strong></summary><br> **Objective:** Ensure all identifiers clearly express their purpose and intent, making code <br>self-documenting<br> **Status:** Passed<br> > Learn more about managing compliance <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#configuration-options'>generic rules</a> or creating your own <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#custom-compliance'>custom rules</a> </details></td></tr> <tr><td> <details><summary><strong>Generic: Robust Error Handling and Edge Case Management</strong></summary><br> **Objective:** Ensure comprehensive error handling that provides meaningful context and graceful <br>degradation<br> **Status:** Passed<br> > Learn more about managing compliance <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#configuration-options'>generic rules</a> or creating your own <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#custom-compliance'>custom rules</a> </details></td></tr> <tr><td> <details><summary><strong>Generic: Secure Error Handling</strong></summary><br> **Objective:** To prevent the leakage of sensitive system information through error messages while <br>providing sufficient detail for internal debugging.<br> **Status:** Passed<br> > Learn more about managing compliance <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#configuration-options'>generic rules</a> or creating your own <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#custom-compliance'>custom rules</a> </details></td></tr> <tr><td> <details><summary><strong>Generic: Secure Logging Practices</strong></summary><br> **Objective:** To ensure logs are useful for debugging and auditing without exposing sensitive <br>information like PII, PHI, or cardholder data.<br> **Status:** Passed<br> > Learn more about managing compliance <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#configuration-options'>generic rules</a> or creating your own <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#custom-compliance'>custom rules</a> </details></td></tr> <tr><td> <details><summary><strong>Generic: Security-First Input Validation and Data Handling</strong></summary><br> **Objective:** Ensure all data inputs are validated, sanitized, and handled securely to prevent <br>vulnerabilities<br> **Status:** Passed<br> > Learn more about managing compliance <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#configuration-options'>generic rules</a> or creating your own <a href='https://qodo-merge-docs.qodo.ai/tools/compliance/#custom-compliance'>custom rules</a> </details></td></tr> <tr><td align="center" colspan="2"> - [ ] Update <!-- /compliance --update_compliance=true --> </td></tr></tbody></table> <details><summary>Compliance status legend</summary> 🟢 - Fully Compliant<br> 🟡 - Partial Compliant<br> 🔴 - Not Compliant<br> ⚪ - Requires Further Human Verification<br> 🏷️ - Compliance label<br> </details>

[github-actions]

Images automagically compressed by Calibre's image-actions ✨

Compression reduced images by 78.2%, saving 1.6 MB.

Filename	Before	After	Improvement	Visual comparison
website_and_docs/static/images/blog/2026/selenium-grid-4-41-deep-dive.jpg	2.1 MB	459.9 KB	78.2%	View diff

[qodo-code-review]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
General	Pin dependency and image versions Pin the dependency version in the coursier fetch command to 4.41.0 and update the browser image tags from :latest to the specific 4.41.0-20260222 version to ensure the example is reproducible. website_and_docs/content/blog/2026/selenium-grid-4-41-deep-dive.md [542-548] # Node with Dynamic Grid on Kubernetes (image mode) java -jar selenium-server.jar \ - --ext $(coursier fetch -p org.seleniumhq.selenium:selenium-node-kubernetes:latest.release) \ + --ext $(coursier fetch -p org.seleniumhq.selenium:selenium-node-kubernetes:4.41.0) \ node \ - -K selenium/standalone-chrome:latest '{"browserName": "chrome"}' \ - -K selenium/standalone-firefox:latest '{"browserName": "firefox"}' \ - -K selenium/standalone-edge:latest '{"browserName": "MicrosoftEdge"}' + -K selenium/standalone-chrome:4.41.0-20260222 '{"browserName": "chrome"}' \ + -K selenium/standalone-firefox:4.41.0-20260222 '{"browserName": "firefox"}' \ + -K selenium/standalone-edge:4.41.0-20260222 '{"browserName": "MicrosoftEdge"}' [Suggestion processed] Suggestion importance[1-10]: 7 __ Why: The suggestion correctly identifies that using latest for dependencies and images in a version-specific blog post undermines reproducibility. Pinning versions to 4.41.0 and its corresponding image tags significantly improves the long-term accuracy and usefulness of the documentation.	Medium
	Clarify ConfigMap key usage Clarify that when using configmap:, the key in the ConfigMap must match the provided , not a fixed value like template, to avoid user confusion. website_and_docs/content/blog/2026/selenium-grid-4-41-deep-dive.md [560] -Noted: The ConfigMap should be deployed to cluster and must contain a key named `template` whose value is a valid K8s Job YAML. The Job must have a container named `browser` with an image. Cross-namespace references use `namespace/configmap-name`. +Note: When using `configmap:<name>`, the ConfigMap must be deployed to the cluster and contain a key matching `<name>` (e.g., `my-chrome-template`). The value of this key must be a valid Kubernetes Job YAML. The Job must define a container named `browser` with an image. Cross-namespace references can be made using `namespace/configmap-name`. Apply / Chat Suggestion importance[1-10]: 6 __ Why: The suggestion correctly identifies a potential point of confusion in the documentation regarding ConfigMap key naming. The proposed change clarifies that the key name is dynamic and corresponds to the command-line argument, which improves the accuracy and clarity of the instructions.	Low
Possible issue	✅ Fix broken commit link Suggestion Impact: The commit did not correct the hash to `a9473df`, but it removed the entire "Commit" column (and thus the broken commit link) from the references table, eliminating the issue indirectly. code diff: @@ -598,29 +593,29 @@ ### Selenium Core (selenium-4.41.0) -| PR | Commit | Description | -|---|---|---| -| [#17015](https://github.com/SeleniumHQ/selenium/pull/17015) | [`0d3c440`](https://github.com/SeleniumHQ/selenium/commit/0d3c44026343785cc651e1218b0545731476efe5) | Add session event API for server-side event bus integration | -| [#17022](https://github.com/SeleniumHQ/selenium/pull/17022) | [`a47041a`](https://github.com/SeleniumHQ/selenium/commit/a47041a5398c7465bc52cac66e3e7d198c5befb5) | Preventing potential deadlock in Distributor | -| [#17060](https://github.com/SeleniumHQ/selenium/pull/17060) | [`a9473df`](https://github.com/SeleniumHQ/selenium/commit/a9473df96d) | Revert default standalone config | -| [#17072](https://github.com/SeleniumHQ/selenium/pull/17072) | [`7278252`](https://github.com/SeleniumHQ/selenium/commit/7278252badc14d9d036df8ca20d6927b5f546a49) | Dynamic Grid standalone support passing basic auth credential | -| [#17092](https://github.com/SeleniumHQ/selenium/pull/17092) | [`1f51b2b`](https://github.com/SeleniumHQ/selenium/commit/1f51b2b20fd08cefa3cb186211dae22f6997076b) | Support Dynamic Grid in Kubernetes cluster | -| [#17097](https://github.com/SeleniumHQ/selenium/pull/17097) | [`ac74b7e`](https://github.com/SeleniumHQ/selenium/commit/ac74b7e263e1308c3f5f8c666c8c2cb97da3e417) | Restore stereotype capabilities merging in RelaySessionFactory | -| [#17104](https://github.com/SeleniumHQ/selenium/pull/17104) | [`d8195c8`](https://github.com/SeleniumHQ/selenium/commit/d8195c8aa617c54d191523a5210f972978965b93) | Fix Distributor thread exhaustion in node health-check cycle | -| [#17106](https://github.com/SeleniumHQ/selenium/pull/17106) | [`741fe01`](https://github.com/SeleniumHQ/selenium/commit/741fe01d276aa67a44b4a6c3590c060fd47d4f2f) | Fix WebSocket connection counter leaks in ProxyNodeWebsockets | -| [#17109](https://github.com/SeleniumHQ/selenium/pull/17109) | [`527a40b`](https://github.com/SeleniumHQ/selenium/commit/527a40b30f01b272c1b7df1de122f8b16e3f79ce) | Distributor retry session when RemoteNode executor shutting down | +| PR | Description | +|---|---| +| [#17015](https://github.com/SeleniumHQ/selenium/pull/17015) | Add session event API for server-side event bus integration | +| [#17022](https://github.com/SeleniumHQ/selenium/pull/17022) | Preventing potential deadlock in Distributor | +| [#17060](https://github.com/SeleniumHQ/selenium/pull/17060) | Revert default standalone config | +| [#17072](https://github.com/SeleniumHQ/selenium/pull/17072) | Dynamic Grid standalone support passing basic auth credential | +| [#17092](https://github.com/SeleniumHQ/selenium/pull/17092) | Support Dynamic Grid in Kubernetes cluster | +| [#17097](https://github.com/SeleniumHQ/selenium/pull/17097) | Restore stereotype capabilities merging in RelaySessionFactory | +| [#17104](https://github.com/SeleniumHQ/selenium/pull/17104) | Fix Distributor thread exhaustion in node health-check cycle | +| [#17106](https://github.com/SeleniumHQ/selenium/pull/17106) | Fix WebSocket connection counter leaks in ProxyNodeWebsockets | +| [#17109](https://github.com/SeleniumHQ/selenium/pull/17109) | Distributor retry session when RemoteNode executor shutting down | Correct the truncated commit hash a9473df96d to the valid short hash a9473df to fix the broken link in the references table. website_and_docs/content/blog/2026/selenium-grid-4-41-deep-dive.md [605] -| [#17060](https://github.com/SeleniumHQ/selenium/pull/17060) | [`a9473df`](https://github.com/SeleniumHQ/selenium/commit/a9473df96d) | Revert default standalone config | +| [#17060](https://github.com/SeleniumHQ/selenium/pull/17060) | [`a9473df`](https://github.com/SeleniumHQ/selenium/commit/a9473df) | Revert default standalone config | [Suggestion processed] Suggestion importance[1-10]: 5 __ Why: The suggestion correctly identifies and fixes a broken link to a commit hash in the references table. This is a useful correction that improves the quality and usability of the documentation for readers wanting to explore the source code changes.	Low
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[diemol]

Small comment, everything else looks fine.

Is this also part of the docs now?