I've configured automatic tools installation (JDK, Maven, Git, ...) in Jenkins with "Extract .zip/.tar" feature pointing to a Nexus URL (like this : "http://nexus:8081/nexus/content/repositories/jenkins-ci-tools/fr/mipih/ic/tools/jdk/oracle-hotspot/1.6.0_25_64bits/oracle-hotspot-1.6.0_25_64bits-linux.zip").

An example of JDK tools declaration in config.xml is in attachment (config-JDK-installs.txt).

The problem is that Jenkins floods Nexus of HTTP requests to download some configured tools every minute.

This feature has been improved by https://issues.jenkins-ci.org/browse/JENKINS-16215 in the version 1.500 of Jenkins but Nexus still faces with a flood of requests returning 304 response.

I've activated access logs of Nexus (nexus-access-log.txt).
Each minute, between 26 and 28 seconds, Jenkins creates more than 130 HTTP requests trying to download some tools parametered in global configuration.
I've 13 tools configured in global configuration.

96 HTTP requests only for oracle-hotspot-1.6.0_25_64bits-linux.zip in 3 seconds.

Each time, the repartition of HTTP requests is the same :
96 - oracle-hotspot-1.6.0_25_64bits-linux.zip
22 - maven-2.2.1.zip
5 - maven-3.0.3.zip
3 - ibm-j9-1.5.0_sr8a_32bits.zip
3 - git-1.7.5.1-aix.zip
1 - maven-3.0.4.zip
1 - oracle-hotspot-1.5.0_22_64bits-linux.zip
1 - oracle-hotspot-1.6.0_26_32bits-windows.zip

I've created this ticket with Critical priority because Nexus is overloaded each day.

I've tried to look in Jenkins core but I cannot see why Jenkins is trying to download again and again these tools. Any idea ?

Jenkins is supposed to call the auto-installer feature only when a build which need a non installed tool is triggered right ? Are there any other cases ?

Thanks in advance!