Golang Server.PurgeTabletActions方法代码示例

// Scrap will update the tablet type to 'Scrap', and remove it from
// the serving graph.
//
// 'force' means we are not on the tablet being scrapped, so it is
// probably dead. So if 'force' is true, we will also remove pending
// remote actions.  And if 'force' is false, we also run an optional
// hook.
func Scrap(ts topo.Server, tabletAlias topo.TabletAlias, force bool) error {
	tablet, err := ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}

	// If you are already scrap, skip updating replication data. It won't
	// be there anyway.
	wasAssigned := tablet.IsAssigned()
	tablet.Type = topo.TYPE_SCRAP
	tablet.Parent = topo.TabletAlias{}
	// Update the tablet first, since that is canonical.
	err = topo.UpdateTablet(ts, tablet)
	if err != nil {
		return err
	}

	// Remove any pending actions. Presumably forcing a scrap
	// means you don't want the agent doing anything and the
	// machine requires manual attention.
	if force {
		err := ts.PurgeTabletActions(tabletAlias, actionnode.ActionNodeCanBePurged)
		if err != nil {
			log.Warningf("purge actions failed: %v", err)
		}
	}

	if wasAssigned {
		err = topo.DeleteTabletReplicationData(ts, tablet.Tablet)
		if err != nil {
			if err == topo.ErrNoNode {
				log.V(6).Infof("no ShardReplication object for cell %v", tablet.Alias.Cell)
				err = nil
			}
			if err != nil {
				log.Warningf("remove replication data for %v failed: %v", tablet.Alias, err)
			}
		}
	}

	// run a hook for final cleanup, only in non-force mode.
	// (force mode executes on the vtctl side, not on the vttablet side)
	if !force {
		hk := hook.NewSimpleHook("postflight_scrap")
		ConfigureTabletHook(hk, tablet.Alias)
		if hookErr := hk.ExecuteOptional(); hookErr != nil {
			// we don't want to return an error, the server
			// is already in bad shape probably.
			log.Warningf("Scrap: postflight_scrap failed: %v", hookErr)
		}
	}

	return nil
}

// Make this external, since in needs to be forced from time to time.
func Scrap(ts topo.Server, tabletAlias topo.TabletAlias, force bool) error {
	tablet, err := ts.GetTablet(tabletAlias)
	if err != nil {
		return err
	}

	// If you are already scrap, skip deleting the path. It won't
	// be correct since the Parent will be cleared already.
	wasAssigned := tablet.IsAssigned()
	replicationPath := ""
	if wasAssigned {
		replicationPath = tablet.ReplicationPath()
	}

	tablet.Type = topo.TYPE_SCRAP
	tablet.Parent = topo.TabletAlias{}
	// Update the tablet first, since that is canonical.
	err = topo.UpdateTablet(ts, tablet)
	if err != nil {
		return err
	}

	// Remove any pending actions. Presumably forcing a scrap means you don't
	// want the agent doing anything and the machine requires manual attention.
	if force {
		err := ts.PurgeTabletActions(tabletAlias, ActionNodeCanBePurged)
		if err != nil {
			log.Warningf("purge actions failed: %v", err)
		}
	}

	if wasAssigned {
		err = ts.DeleteReplicationPath(tablet.Keyspace, tablet.Shard, replicationPath)
		if err != nil {
			switch err {
			case topo.ErrNoNode:
				log.V(6).Infof("no replication path: %v", replicationPath)
				err = nil
			case topo.ErrNotEmpty:
				// If you are forcing the scrapping of a master, you can't update the
				// replication graph yet, since other nodes are still under the impression
				// they are slaved to this tablet.
				// If the node was not empty, we can't do anything about it - the replication
				// graph needs to be fixed by reparenting. If the action was forced, assume
				// the user knows best and squelch the error.
				if tablet.Parent.Uid == topo.NO_TABLET && force {
					err = nil
				}
			}
			if err != nil {
				log.Warningf("remove replication path failed: %v %v", replicationPath, err)
			}
		}
	}

	// run a hook for final cleanup, only in non-force mode.
	// (force mode executes on the vtctl side, not on the vttablet side)
	if !force {
		hk := hook.NewSimpleHook("postflight_scrap")
		configureTabletHook(hk, tablet.Alias())
		if hookErr := hk.ExecuteOptional(); hookErr != nil {
			// we don't want to return an error, the server
			// is already in bad shape probably.
			log.Warningf("Scrap: postflight_scrap failed: %v", hookErr)
		}
	}

	return nil
}

//.........这里部分代码省略.........

	interrupted := make(chan struct{}, 1)
	if _, err := ts.WaitForTabletAction(actionPath, time.Second/100, interrupted); err != topo.ErrTimeout {
		t.Errorf("WaitForTabletAction returned %v", err)
	}
	go func() {
		time.Sleep(time.Second / 10)
		close(interrupted)
	}()
	if _, err := ts.WaitForTabletAction(actionPath, time.Second*5, interrupted); err != topo.ErrInterrupted {
		t.Errorf("WaitForTabletAction returned %v", err)
	}

	// wait for the result in one thread
	wg1 := sync.WaitGroup{}
	wg1.Add(1)
	go func() {
		defer wg1.Done()
		interrupted := make(chan struct{}, 1)
		var err error
		for i := 0; i <= 30; i++ {
			var result string
			result, err = ts.WaitForTabletAction(actionPath, time.Second, interrupted)
			if err == topo.ErrTimeout {
				// we waited for one second, didn't see the
				// result, try again up to 30 seconds.
				t.Logf("WaitForTabletAction timed out at try %v/30", i)
				continue
			}
			if err != nil {
				t.Errorf("WaitForTabletAction returned: %v", err)
			}
			if result != "contents3" {
				t.Errorf("WaitForTabletAction returned bad result: %v", result)
			}
			return
		}
		t.Errorf("WaitForTabletAction timed out: %v", err)
	}()

	// process the action in another thread
	done := make(chan struct{}, 1)
	wg2 := sync.WaitGroup{}
	wg2.Add(1)
	go ts.ActionEventLoop(tabletAlias, func(ap, data string) error {
		// the actionPath sent back to the action processor
		// is the exact one we have in normal cases,
		// but for the tee, we add extra information.
		if ap != actionPath && !strings.HasSuffix(ap, actionPath) {
			t.Errorf("Bad action path: %v", ap)
		}
		if data != "contents1" {
			t.Errorf("Bad data: %v", data)
		}
		ta, contents, version, err := ts.ReadTabletActionPath(ap)
		if err != nil {
			t.Errorf("Error from ReadTabletActionPath: %v", err)
		}
		if contents != data {
			t.Errorf("Bad contents: %v", contents)
		}
		if ta != tabletAlias {
			t.Errorf("Bad tablet alias: %v", ta)
		}

		if err := ts.UpdateTabletAction(ap, "contents2", version); err != nil {
			t.Errorf("UpdateTabletAction failed: %v", err)
		}
		if err := ts.StoreTabletActionResponse(ap, "contents3"); err != nil {
			t.Errorf("StoreTabletActionResponse failed: %v", err)
		}
		if err := ts.UnblockTabletAction(ap); err != nil {
			t.Errorf("UnblockTabletAction failed: %v", err)
		}

		wg2.Done()
		return nil
	}, done)

	// first wait for the processing to be done, then close the
	// action loop, then wait for the response to be received.
	wg2.Wait()
	close(done)
	wg1.Wait()

	// start an action, and try to purge all actions, to test
	// PurgeTabletActions
	actionPath, err = ts.WriteTabletAction(tabletAlias, "contents2")
	if err != nil {
		t.Fatalf("WriteTabletAction(contents2): %v", err)
	}
	if err := ts.PurgeTabletActions(tabletAlias, func(data string) bool {
		return true
	}); err != nil {
		t.Fatalf("PurgeTabletActions(contents2) failed: %v", err)
	}
	if _, _, _, err := ts.ReadTabletActionPath(actionPath); err != topo.ErrNoNode {
		t.Fatalf("ReadTabletActionPath(contents2) should have failed with ErrNoNode: %v", err)
	}
}