func (s *Scheduler) HandleHostEvent(e *discoverd.Event) {
log := s.logger.New("fn", "HandleHostEvent", "event.type", e.Kind)
log.Info("handling host event")
switch e.Kind {
case discoverd.EventKindUp:
s.handleNewHost(e.Instance.Meta["id"])
case discoverd.EventKindUpdate:
id := e.Instance.Meta["id"]
_, isShutdown := e.Instance.Meta["shutdown"]
// if we haven't seen this host before, handle it as new
// (provided it is not shutdown)
host, ok := s.hosts[id]
if !ok {
if !isShutdown {
s.handleNewHost(id)
}
return
}
// if the host is shutdown, just mark it as shutdown and return
// rather than explicitly unfollowing to avoid a race where
// SyncHosts could run before we get the down event, thus
// re-following a host we know is shutdown (the host will be
// unfollowed when we get the eventual down event)
if isShutdown {
log.Info("marking host as shutdown", "host.id", host.ID)
host.shutdown = true
return
}
// if the host's tags have changed, rectify all formations so
// that any running jobs with mismatched tags are stopped, and
// also try to start pending jobs in case tags now match
tags := cluster.HostTagsFromMeta(e.Instance.Meta)
if !host.TagsEqual(tags) {
log.Info("host tags changed", "host.id", id, "from", host.Tags, "to", tags)
host.Tags = tags
s.rectifyAll()
s.maybeStartPendingTagJobs(host)
}
case discoverd.EventKindDown:
id := e.Instance.Meta["id"]
log = log.New("host.id", id)
host, ok := s.hosts[id]
if !ok {
log.Warn("ignoring host down event, unknown host")
return
}
if host.shutdown {
s.unfollowHost(host)
} else {
s.markHostAsUnhealthy(host)
}
}
}
func (s *Scheduler) HandleHostEvent(e *discoverd.Event) {
log := logger.New("fn", "HandleHostEvent", "event.type", e.Kind)
log.Info("handling host event")
var err error
defer func() {
s.sendEvent(EventTypeHostEvent, err, nil)
}()
switch e.Kind {
case discoverd.EventKindUp:
s.handleNewHost(e.Instance.Meta["id"])
case discoverd.EventKindUpdate:
id := e.Instance.Meta["id"]
// if we haven't seen this host before, handle it as new
host, ok := s.hosts[id]
if !ok {
s.handleNewHost(id)
return
}
// if the host's tags have changed, rectify all formations so
// that any running jobs with mismatched tags are stopped, and
// also try to start pending jobs in case tags now match
tags := cluster.HostTagsFromMeta(e.Instance.Meta)
if !host.TagsEqual(tags) {
log.Info("host tags changed", "host.id", id, "from", host.Tags, "to", tags)
host.Tags = tags
s.rectifyAll()
s.maybeStartPendingTagJobs(host)
}
case discoverd.EventKindDown:
id := e.Instance.Meta["id"]
log = log.New("host.id", id)
host, ok := s.hosts[id]
if !ok {
log.Warn("ignoring host down event, unknown host")
return
}
s.markHostAsUnhealthy(host)
}
}