// etcd needs to be initialized beforehand
func TestControllerInitEtcdLayout(t *testing.T) {
etcdClient := etcd.NewClient([]string{"http://localhost:4001"})
tests := []struct {
name string
numberOfTasks uint64
}{
{"test-1", 2},
{"test-2", 4},
}
for i, tt := range tests {
c := New(tt.name, etcdClient, tt.numberOfTasks, []string{"Parents", "Children"})
c.InitEtcdLayout()
for taskID := uint64(0); taskID < tt.numberOfTasks; taskID++ {
key := etcdutil.FreeTaskPath(c.name, strconv.FormatUint(taskID, 10))
if _, err := etcdClient.Get(key, false, false); err != nil {
t.Errorf("task %d: etcdClient.Get %v failed: %v", i, key, err)
}
key = etcdutil.MetaPath(c.name, taskID)
if _, err := etcdClient.Get(key, false, false); err != nil {
t.Errorf("task %d: etcdClient.Get %v failed: %v", i, key, err)
}
}
c.DestroyEtcdLayout()
}
}
// watch meta flag and receive any notification.
func (f *framework) watchMeta() {
watchPath := etcdutil.MetaPath(f.name, f.taskID)
// The function parses the watch response of meta flag, and passes the result
// to central event handling.
responseHandler := func(resp *etcd.Response) {
// Note: Why "get"?
// We first try to get the index. If there's value in it, we also parse it.
if resp.Action != "set" && resp.Action != "get" {
return
}
epoch, taskID, linkType, meta, err := parseMetaValue(resp.Node.Value)
if err != nil {
f.log.Panicf("parseMetaValue failed: %v", err)
}
f.metaChan <- &metaChange{
from: taskID,
epoch: epoch,
linkType: linkType,
meta: meta,
}
}
f.metaWatchStop = make(chan bool, 1)
// Need to pass in taskID to make it work. Didn't know why.
err := etcdutil.WatchMeta(f.etcdClient, watchPath, f.metaWatchStop, responseHandler)
if err != nil {
f.log.Panicf("WatchMeta failed. path: %s, err: %v", watchPath, err)
}
}
func (f *framework) FlagMeta(ctx context.Context, linkType, meta string) {
epoch, ok := ctx.Value(epochKey).(uint64)
if !ok {
f.log.Panicf("Can not find epochKey in FlagMeta, epoch: %d", epoch)
}
// send the meta change notification to every task of specified link type.
for _, id := range f.topology[linkType].GetNeighbors(epoch) {
// The value is made of "epoch-fromID-metadata"
//
// Epoch is prepended to meta. When a new one starts and replaces
// the old one, it doesn't need to handle previous things, whose
// epoch is smaller than current one.
value := fmt.Sprintf("%d-%d-%s-%s", epoch, f.taskID, linkType, meta)
_, err := f.etcdClient.Set(etcdutil.MetaPath(f.name, id), value, 0)
if err != nil {
f.log.Panicf("etcdClient.Set failed; key: %s, value: %s, error: %v",
etcdutil.MetaPath(f.name, id), value, err)
}
}
}
func (c *Controller) InitEtcdLayout() error {
// Initilize the job epoch to 0
etcdutil.MustCreate(c.etcdclient, c.logger, etcdutil.EpochPath(c.name), "0", 0)
c.setupWatchOnJobStatus()
// initiate etcd data layout for tasks
// currently it creates as many unassigned tasks as task masters.
for i := uint64(0); i < c.numOfTasks; i++ {
key := etcdutil.FreeTaskPath(c.name, strconv.FormatUint(i, 10))
etcdutil.MustCreate(c.etcdclient, c.logger, key, "", 0)
key = etcdutil.MetaPath(c.name, i)
etcdutil.MustCreate(c.etcdclient, c.logger, key, "", 0)
}
return nil
}