Resolving Common Jenkins Compatibility Issues and Optimizing Performance

Performance Plugin Compatibility Issues

In freestyle projects, the Performance plugin collects build artifacts, but with the latest versions (Jenkins v2.298, Performance v3.19) it conflicts with Jenkins, causing table and div misalignment on the configuration page and preventing saving. The issue has persisted for months without a fix. Workarounds are:

Convert the freestyle job to a pipeline.

Manually edit the job’s config.xml on the server to enable saving.

Downgrade Jenkins; the plugin works on v2.263.4 LTS after backing up and checking other plugin compatibility.

Modifying Jenkins CSP Security Policy

When using the Robot Framework Plugin, previewing test reports fails with “Opening Robot Framework log failed” because Jenkins’s default Content‑Security‑Policy (CSP) blocks external HTML/JS. The default CSP is:

sandbox; default-src 'none'; img-src 'self'; style-src 'self';

To relax the policy, create a startup job that runs a Groovy script:

Create a new job that runs on Jenkins startup.

In “Build Triggers”, select “Build when node starts”, leave label blank, set quiet period to 0.

In “Build”, choose “Execute system Groovy” and run:

System.setProperty("hudson.model.DirectoryBrowserSupport.CSP", "")

Restart Jenkins; the Robot Framework report can now be accessed.

Custom Jenkins Context Path

When Jenkins is behind an Nginx proxy with other applications, you may need a custom relative path (e.g., /jenkins). Steps:

Edit jenkins.xml in the Jenkins installation directory.

Append --prefix="/jenkins" to the arguments node.

Restart Jenkins and access via http://localhost:29908/jenkins.

Test the proxy.

If agents were already connected via JNLP before the proxy change, update the jnlpUrl in jenkins-slave.xml accordingly.

git clone failure: Killed by signal 15

Large repositories or slow networks may exceed the default 10‑minute clone timeout, causing Jenkins to kill the job. Increase the timeout in the job configuration to prevent the failure.

Build step “Execute Windows batch command” marked build as failure

Add exit 0 as the last line of the batch script to ensure the step returns success.

Replacing vulnerable JAR in Jenkins running on Tomcat

To replace commons-fileupload-1.3.1-jenkins-2.jar with version 1.4, create a symbolic link to the new JAR, delete the old one, and restart Tomcat.

mklink webapps\jenkins\WEB-INF\lib\commons-fileupload-1.3.1-jenkins-2.jar webapps\jenkins\WEB-INF\lib\commons-fileupload-1.4.jar

Running JNLP files on Windows agents

If double‑clicking a .jnlp file does nothing, run it from the command line with javaws slave-agent.jnlp and adjust Java security settings as needed.

Disabling CSRF Protection

For Jenkins versions before v2.204.6, CSRF can be disabled in the global security settings. In newer versions, add the JVM argument

-Dhudson.security.csrf.GlobalCrumbIssuerConfiguration.DISABLE_CSRF_PROTECTION=true

either in Tomcat startup scripts or when launching the Jenkins JAR.

-Dhudson.security.csrf.GlobalCrumbIssuerConfiguration.DISABLE_CSRF_PROTECTION=true

Adjusting JVM Memory Settings

Default JVM memory may be insufficient, leading to OutOfMemoryError: PermGen space. Example settings:

set JAVA_OPTS=
 -server
 -Xms5000M
 -Xmx5000M
 -Xss512k
 -XX:+AggressiveOpts
 -XX:+UseBiasedLocking
 -XX:PermSize=256M
 -XX:MaxPermSize=512M
 -XX:+DisableExplicitGC
 -XX:MaxTenuringThreshold=31
 -XX:+UseConcMarkSweepGC
 -XX:+UseParNewGC
 -XX:+CMSParallelRemarkEnabled
 -XX:+UseCMSCompactAtFullCollection
 -XX:LargePageSizeInBytes=128m
 -XX:+UseFastAccessorMethods
 -XX:+UseCMSInitiatingOccupancyOnly
 -Djava.awt.headless=true

Optimizing Disk Space Usage

Configure build discard policies to keep only recent builds (e.g., retain builds from the last 2 days and a maximum of 30 builds). Use the Disk Usage plugin cautiously as it may cause server lag.

Set up a scheduled job to delete old Tomcat logs to prevent log accumulation.

Setting Build Timeout

Configure a timeout for jobs that hang excessively to avoid high memory consumption and potential Jenkins crashes.

Configuring Global Properties

Define environment variables in “Manage Jenkins → Configure System → Global properties” to avoid hard‑coding values in pipelines.

Managing Scripts Centrally

Install the “Managed script” plugin, add Groovy scripts under “Managed files”, and invoke them via “Execute managed script” in jobs.

Lightweight Backup

Use the “ThinBackup” plugin for full or incremental Jenkins configuration backups without stopping the server; it does not back up build history or artifacts.

To restore a backup, use the plugin’s restore function.