Docker: Add Node env var SE_NODE_CONNECTION_LIMIT_PER_SESSION and README (#2855)

VietND96 · web-flow · commit dbdfc1f88e11 · 2025-06-07T01:39:22.000+07:00
Signed-off-by: Viet Nguyen Duc &lt;nguyenducviet4496@gmail.com&gt;
diff --git a/ENV_VARIABLES.md b/ENV_VARIABLES.md
@@ -144,4 +144,6 @@
 | SE_NODE_REGISTER_SHUTDOWN_ON_FAILURE | true | If this flag is enabled, the Node will shut down after the register period is completed. This is useful for container environments to restart and register again. If restarted multiple times, the Node container status will be CrashLoopBackOff | --register-shutdown-on-failure |
 | SE_NODE_RELAY_BROWSER_VERSION |  |  |  |
 | SE_NODE_RELAY_ONLY | true |  |  |
-| SE_EXTRA_LIBS | | Extra jars to add to the classpath | --ext |
+| SE_EXTRA_LIBS |  | Extra jars to add to the classpath in server component bootstrap | --ext |
+| SE_NODE_CONNECTION_LIMIT_PER_SESSION | 10 |  |  |
+| SE_SUPERVISORD_UNIX_SERVER_PASSWORD | secret |  |  |
diff --git a/NodeBase/Dockerfile b/NodeBase/Dockerfile
@@ -49,6 +49,7 @@ ENV LANG_WHICH=${LANG_WHICH} \
     SE_NODE_REGISTER_PERIOD="120" \
     SE_NODE_REGISTER_CYCLE="10" \
     SE_NODE_REGISTER_SHUTDOWN_ON_FAILURE="true" \
+    SE_NODE_CONNECTION_LIMIT_PER_SESSION="10" \
     SE_OTEL_SERVICE_NAME="selenium-node" \
     SE_NODE_RELAY_ONLY="true" \
     # Setting Selenium Manager to work offline
diff --git a/README.md b/README.md
@@ -1901,5 +1901,14 @@ mkdir /tmp/videos
 chown 1200:1201 /tmp/videos
 ```
 
+### Websocket connections per session get exhausted
+
+> org.openqa.selenium.remote.http.ConnectionFailedException: JdkWebSocket initial request execution error`
+
+This was reported in [#2850](https://github.com/SeleniumHQ/docker-selenium/issues/2850).
+Actually, from Grid version v4.26.0+, in Node CLI option `--connection-limit-per-session` (`SE_NODE_CONNECTION_LIMIT_PER_SESSION` environment variable) is set to `10` by default. Let X be the maximum number of websocket connections per session.This will ensure one session is not able to exhaust the connection limit of the host. Websocket connection might come from enable CDP, BiDi.
+
+Your test scenario or test framework implementation might be creating more than `X` connections per session, which will lead to the error above. You can optimize your implementation to use less connections per session, or you can increase the limit by setting the environment variable `SE_NODE_CONNECTION_LIMIT_PER_SESSION` to a value higher than `10` to allow more connections per session.
+
 ## Stargazers over time
 [![Stargazers over time](https://starchart.cc/SeleniumHQ/docker-selenium.svg?variant=adaptive)](https://starchart.cc/SeleniumHQ/docker-selenium)
diff --git a/scripts/generate_list_env_vars/description.yaml b/scripts/generate_list_env_vars/description.yaml
@@ -440,3 +440,12 @@
 - name: SE_NODE_RELAY_ONLY
   description: ''
   cli: ''
+- name: SE_EXTRA_LIBS
+  description: Extra jars to add to the classpath in server component bootstrap
+  cli: --ext
+- name: SE_NODE_CONNECTION_LIMIT_PER_SESSION
+  description: ''
+  cli: ''
+- name: SE_SUPERVISORD_UNIX_SERVER_PASSWORD
+  description: ''
+  cli: ''
diff --git a/scripts/generate_list_env_vars/value.yaml b/scripts/generate_list_env_vars/value.yaml
@@ -36,6 +36,8 @@
   default: '4443'
 - name: SE_EXTERNAL_URL
   default: ''
+- name: SE_EXTRA_LIBS
+  default: ''
 - name: SE_FRAME_RATE
   default: '15'
 - name: SE_GRID_URL
@@ -78,6 +80,8 @@
   default: ''
 - name: SE_NODE_BROWSER_VERSION
   default: stable
+- name: SE_NODE_CONNECTION_LIMIT_PER_SESSION
+  default: '200'
 - name: SE_NODE_CONTAINER_NAME
   default: ''
 - name: SE_NODE_DOCKER_CONFIG_FILENAME
@@ -240,6 +244,8 @@
   default: /tmp/supervisord.pid
 - name: SE_SUPERVISORD_START_RETRIES
   default: '5'
+- name: SE_SUPERVISORD_UNIX_SERVER_PASSWORD
+  default: secret
 - name: SE_UPLOAD_COMMAND
   default: ''
 - name: SE_UPLOAD_DESTINATION_PREFIX
