How to improve Jenkins Pipelines overall performance on OpenShift?

Issue

• Jenkins Pipelines are taking too long to finish
• Every time an application build is running inside a Jenkins slave, all libraries have to be downloaded from the central repository
• Builds inside Jenkins slaves are taken too long to to
• There are a lot of Jenkins slaves pods in running state but actually not building anything
• How to increase Jenkins executor queue?
• How to increase Jenkins master resources?
• How to increase Jenkins slaves resources?
• Is it possible to add a volume to multiple Jenkins slaves?