Method handleServerGroupUpdates

server_groups.go:82–208

handleServerGroupUpdates listens to the server group updates and debounces the updates to minimise the config writes. It reuses the cfg debounce configuration values.

()

// and debounces the updates to minimise the config writes.
// It reuses the cfg debounce configuration values.
func (st *serverGroupTracker) handleServerGroupUpdates() {
	if st.mgr.Cfg() == nil {
		return
	}

	// get the config debounce offset and node offset multiplier.
	offset, nm := st.mgr.GetCfgDeBounceOffsetAndMultiplier()

	// compute the node specific offset from the node index.
	pos := 1
	nodeDefs, _ := st.mgr.GetNodeDefs(cbgt.NODE_DEFS_KNOWN, false)
	if nodeDefs != nil {
		for _, nodeDef := range nodeDefs.NodeDefs {
			if nodeDef.UUID == st.mgr.UUID() {
				break
			}
			pos++
		}
	}

	dbinterval := nm * pos * offset
	log.Printf("server_groups: debounce duration: %d MS", dbinterval)

	var resp *streamingPoolResponse

	go func() {

		for {

			resp = <-st.notifCh

			debounceTimeCh := time.After(time.Millisecond * time.Duration(dbinterval))
		DEBOUNCE_LOOP:
			for {

				select {
				case resp = <-st.notifCh:
					// NOOP upon more updates.
				case <-debounceTimeCh:
					break DEBOUNCE_LOOP
				}
			}

			if !strings.Contains(resp.ServerGroupsUri, "v=") {
				log.Printf("server_groups: no rev found %s",
					resp.ServerGroupsUri)
				continue
			}

			// parse the server group revision number.
			var msgs []string
			rev := resp.ServerGroupsUri[strings.Index(
				resp.ServerGroupsUri, "v=")+2:]

			// skip if there is no change in the server group rev numbers.
			if rev == st.prevRev {
				continue
			}