LBaaS operations like creating or listing are slow

Issue

Some LBaaS operations like creating pools or listing objects take too long. Once the number of LBaaS objects start to grow, time of creation or listing increases exponentially.

For example, the first pool created with a F5 backend takes 52 seconds and 30 seconds when HAProxy is used as backend. If 20 pools are created, the creation of the last pool takes 163 seconds with F5 and 118 with HAProxy.