Check_MK Werk 8422: Fix deadlock in CMC when creating lots of RRDs at once

ID: 8422 Title: Fix deadlock in CMC when creating lots of RRDs at once Component: Metrics System Level: 2 Class: Bug Fix Version: 1.2.9i1 This could e.g. happen if you add many hosts and services to the monitoring at once. The CMC would then stuck in a dead lock with the RRD creation helper process. This has been fixed.