flowchart TD
		subgraph Thread 1: watch catalog
		A[Start] --> catalog{Catalog any change?}
    catalog -->|Yes| cindex[return catalog index]
    catalog ---->|No| cblock[block query until catalog any change]
    cblock --> E[End]
    cindex --> E
    end
    
    subgraph Thread 2: watch health
    A2[Start] --> health2{health any change?}
    health2 -->|Yes| hindex[return health index]
    health2 ---->|No| hblock[block query until health any change]
    hblock --> E2[End]
    hindex --> E2
    end
    
    subgraph Wait any thread
    A3[Start] --> spawn[Spawn TWO threads]
    spawn --> wait[wait any Thread]
    wait --> catalog2[Query all services]
    catalog2 --> H[Query health nodes]
    H --> update[Update all services]
    update --> e[End]
    end