Golang keys.RangeMetaKey函數代碼示例

func metaKey(key roachpb.RKey) []byte {
	rk, err := keys.Addr(keys.RangeMetaKey(key))
	if err != nil {
		panic(err)
	}
	return rk
}

// rangeAddressing updates or deletes the range addressing metadata
// for the range specified by desc. The action to take is specified by
// the supplied metaAction function.
//
// The rules for meta1 and meta2 records are as follows:
//
//  1. If desc.StartKey or desc.EndKey is meta1:
//     - ERROR
//  2. If desc.EndKey is meta2:
//     - meta1(desc.EndKey)
//  3. If desc.EndKey is normal user key:
//     - meta2(desc.EndKey)
//     3a. If desc.StartKey is KeyMin or meta2:
//         - meta1(KeyMax)
func rangeAddressing(b *client.Batch, desc *roachpb.RangeDescriptor, action metaAction) error {
	// 1. handle illegal case of start or end key being meta1.
	if bytes.HasPrefix(desc.EndKey, keys.Meta1Prefix) ||
		bytes.HasPrefix(desc.StartKey, keys.Meta1Prefix) {
		return errors.Errorf("meta1 addressing records cannot be split: %+v", desc)
	}

	// Note that both cases 2 and 3 are handled by keys.RangeMetaKey.
	//
	// 2. the case of the range ending with a meta2 prefix. This means
	// the range is full of meta2. We must update the relevant meta1
	// entry pointing to the end of this range.
	//
	// 3. the range ends with a normal user key, so we must update the
	// relevant meta2 entry pointing to the end of this range.
	action(b, keys.RangeMetaKey(desc.EndKey), desc)

	if !bytes.HasPrefix(desc.EndKey, keys.Meta2Prefix) {
		// 3a. the range starts with KeyMin or a meta2 addressing record,
		// update the meta1 entry for KeyMax.
		if bytes.Equal(desc.StartKey, roachpb.RKeyMin) ||
			bytes.HasPrefix(desc.StartKey, keys.Meta2Prefix) {
			action(b, keys.Meta1KeyMax, desc)
		}
	}
	return nil
}

// LookupRange returns the descriptor of the range containing key.
func (ts *TestServer) LookupRange(key roachpb.Key) (roachpb.RangeDescriptor, error) {
	rangeLookupReq := roachpb.RangeLookupRequest{
		Span: roachpb.Span{
			Key: keys.RangeMetaKey(keys.MustAddr(key)),
		},
		MaxRanges: 1,
	}
	resp, pErr := client.SendWrapped(context.Background(), ts.DistSender(), &rangeLookupReq)
	if pErr != nil {
		return roachpb.RangeDescriptor{}, errors.Errorf(
			"%q: lookup range unexpected error: %s", key, pErr)
	}
	return resp.(*roachpb.RangeLookupResponse).Ranges[0], nil
}

func (c *Cluster) lookupRange(nodeIdx int, key roachpb.Key) (*roachpb.RangeDescriptor, error) {
	req := &roachpb.RangeLookupRequest{
		Span: roachpb.Span{
			Key: keys.RangeMetaKey(keys.MustAddr(key)),
		},
		MaxRanges: 1,
	}
	sender := c.Clients[nodeIdx].GetSender()
	resp, pErr := client.SendWrapped(context.Background(), sender, req)
	if pErr != nil {
		return nil, errors.Errorf("%s: lookup range: %s", key, pErr)
	}
	return &resp.(*roachpb.RangeLookupResponse).Ranges[0], nil
}

func runLsRanges(cmd *cobra.Command, args []string) error {
	if len(args) > 1 {
		return usageAndError(cmd)
	}

	var startKey roachpb.Key
	{
		k := roachpb.KeyMin.Next()
		if len(args) > 0 {
			k = roachpb.Key(args[0])
		}
		rk, err := keys.Addr(k)
		if err != nil {
			panic(err)
		}
		startKey = keys.RangeMetaKey(rk)
	}
	endKey := keys.Meta2Prefix.PrefixEnd()

	kvDB, stopper, err := MakeDBClient()
	if err != nil {
		return err
	}
	defer stopper.Stop()

	rows, err := kvDB.Scan(context.Background(), startKey, endKey, maxResults)
	if err != nil {
		return err
	}

	for _, row := range rows {
		desc := &roachpb.RangeDescriptor{}
		if err := row.ValueProto(desc); err != nil {
			return errors.Wrapf(err, "unable to unmarshal range descriptor at %s", row.Key)
		}
		fmt.Printf("%s-%s [%d]\n", desc.StartKey, desc.EndKey, desc.RangeID)
		for i, replica := range desc.Replicas {
			fmt.Printf("\t%d: node-id=%d store-id=%d\n",
				i, replica.NodeID, replica.StoreID)
		}
	}
	fmt.Printf("%d result(s)\n", len(rows))
	return nil
}

// TableStats is an endpoint that returns columns, indices, and other
// relevant details for the specified table.
func (s *adminServer) TableStats(
	ctx context.Context, req *serverpb.TableStatsRequest,
) (*serverpb.TableStatsResponse, error) {
	// Get table span.
	var tableSpan roachpb.Span
	iexecutor := sql.InternalExecutor{LeaseManager: s.server.leaseMgr}
	if err := s.server.db.Txn(ctx, func(txn *client.Txn) error {
		var err error
		tableSpan, err = iexecutor.GetTableSpan(s.getUser(req), txn, req.Database, req.Table)
		return err
	}); err != nil {
		return nil, s.serverError(err)
	}

	startKey, err := keys.Addr(tableSpan.Key)
	if err != nil {
		return nil, s.serverError(err)
	}
	endKey, err := keys.Addr(tableSpan.EndKey)
	if err != nil {
		return nil, s.serverError(err)
	}

	// Get current range descriptors for table. This is done by scanning over
	// meta2 keys for the range.
	rangeDescKVs, err := s.server.db.Scan(ctx, keys.RangeMetaKey(startKey), keys.RangeMetaKey(endKey), 0)
	if err != nil {
		return nil, s.serverError(err)
	}

	// Extract a list of node IDs from the response.
	nodeIDs := make(map[roachpb.NodeID]struct{})
	for _, kv := range rangeDescKVs {
		var rng roachpb.RangeDescriptor
		if err := kv.Value.GetProto(&rng); err != nil {
			return nil, s.serverError(err)
		}
		for _, repl := range rng.Replicas {
			nodeIDs[repl.NodeID] = struct{}{}
		}
	}

	// Construct TableStatsResponse by sending an RPC to every node involved.
	tableStatResponse := serverpb.TableStatsResponse{
		NodeCount:  int64(len(nodeIDs)),
		RangeCount: int64(len(rangeDescKVs)),
	}
	type nodeResponse struct {
		nodeID roachpb.NodeID
		resp   *serverpb.SpanStatsResponse
		err    error
	}

	// Send a SpanStats query to each node. Set a timeout on the context for
	// these queries.
	responses := make(chan nodeResponse)
	nodeCtx, cancel := context.WithTimeout(ctx, base.NetworkTimeout)
	defer cancel()
	for nodeID := range nodeIDs {
		nodeID := nodeID
		if err := s.server.stopper.RunAsyncTask(nodeCtx, func(ctx context.Context) {
			var spanResponse *serverpb.SpanStatsResponse
			client, err := s.server.status.dialNode(nodeID)
			if err == nil {
				req := serverpb.SpanStatsRequest{
					StartKey: startKey,
					EndKey:   endKey,
					NodeID:   nodeID.String(),
				}
				spanResponse, err = client.SpanStats(ctx, &req)
			}

			response := nodeResponse{
				nodeID: nodeID,
				resp:   spanResponse,
				err:    err,
			}
			select {
			case responses <- response:
				// Response processed.
			case <-ctx.Done():
				// Context completed, response no longer needed.
			}
		}); err != nil {
			return nil, err
		}
	}
	for remainingResponses := len(nodeIDs); remainingResponses > 0; remainingResponses-- {
		select {
		case resp := <-responses:
			// For nodes which returned an error, note that the node's data
			// is missing. For successful calls, aggregate statistics.
			if resp.err != nil {
				tableStatResponse.MissingNodes = append(
					tableStatResponse.MissingNodes,
					serverpb.TableStatsResponse_MissingNode{
						NodeID:       resp.nodeID.String(),
						ErrorMessage: resp.err.Error(),
//.........這裏部分代碼省略.........

// process performs a consistent lookup on the range descriptor to see if we are
// still a member of the range.
func (rgcq *replicaGCQueue) process(
	ctx context.Context, repl *Replica, _ config.SystemConfig,
) error {
	// Note that the Replicas field of desc is probably out of date, so
	// we should only use `desc` for its static fields like RangeID and
	// StartKey (and avoid rng.GetReplica() for the same reason).
	desc := repl.Desc()

	// Calls to RangeLookup typically use inconsistent reads, but we
	// want to do a consistent read here. This is important when we are
	// considering one of the metadata ranges: we must not do an
	// inconsistent lookup in our own copy of the range.
	b := &client.Batch{}
	b.AddRawRequest(&roachpb.RangeLookupRequest{
		Span: roachpb.Span{
			Key: keys.RangeMetaKey(desc.StartKey),
		},
		MaxRanges: 1,
	})
	if err := rgcq.db.Run(ctx, b); err != nil {
		return err
	}
	br := b.RawResponse()
	reply := br.Responses[0].GetInner().(*roachpb.RangeLookupResponse)

	if len(reply.Ranges) != 1 {
		return errors.Errorf("expected 1 range descriptor, got %d", len(reply.Ranges))
	}

	replyDesc := reply.Ranges[0]
	if _, currentMember := replyDesc.GetReplicaDescriptor(repl.store.StoreID()); !currentMember {
		// We are no longer a member of this range; clean up our local data.
		rgcq.metrics.RemoveReplicaCount.Inc(1)
		log.VEventf(ctx, 1, "destroying local data")
		if err := repl.store.RemoveReplica(ctx, repl, replyDesc, true); err != nil {
			return err
		}
	} else if desc.RangeID != replyDesc.RangeID {
		// If we get a different range ID back, then the range has been merged
		// away. But currentMember is true, so we are still a member of the
		// subsuming range. Shut down raft processing for the former range
		// and delete any remaining metadata, but do not delete the data.
		rgcq.metrics.RemoveReplicaCount.Inc(1)
		log.VEventf(ctx, 1, "removing merged range")
		if err := repl.store.RemoveReplica(ctx, repl, replyDesc, false); err != nil {
			return err
		}

		// TODO(bdarnell): remove raft logs and other metadata (while leaving a
		// tombstone). Add tests for GC of merged ranges.
	} else {
		// This replica is a current member of the raft group. Set the last replica
		// GC check time to avoid re-processing for another check interval.
		//
		// TODO(tschottdorf): should keep stats in particular on this outcome
		// but also on how good a job the queue does at inspecting every
		// Replica (see #8111) when inactive ones can be starved by
		// event-driven additions.
		log.Event(ctx, "not gc'able")
		if err := repl.setLastReplicaGCTimestamp(ctx, repl.store.Clock().Now()); err != nil {
			return err
		}
	}

	return nil
}

// TestRangeLookupUseReverse tests whether the results and the results count
// are correct when scanning in reverse order.
func TestRangeLookupUseReverse(t *testing.T) {
	defer leaktest.AfterTest(t)()
	storeCfg := storage.TestStoreConfig(nil)
	storeCfg.TestingKnobs.DisableSplitQueue = true
	store, stopper := createTestStoreWithConfig(t, storeCfg)
	defer stopper.Stop()

	// Init test ranges:
	// ["","a"), ["a","c"), ["c","e"), ["e","g") and ["g","\xff\xff").
	splits := []roachpb.AdminSplitRequest{
		adminSplitArgs(roachpb.Key("g"), roachpb.Key("g")),
		adminSplitArgs(roachpb.Key("e"), roachpb.Key("e")),
		adminSplitArgs(roachpb.Key("c"), roachpb.Key("c")),
		adminSplitArgs(roachpb.Key("a"), roachpb.Key("a")),
	}

	for _, split := range splits {
		_, pErr := client.SendWrapped(context.Background(), rg1(store), &split)
		if pErr != nil {
			t.Fatalf("%q: split unexpected error: %s", split.SplitKey, pErr)
		}
	}

	// Resolve the intents.
	scanArgs := roachpb.ScanRequest{
		Span: roachpb.Span{
			Key:    keys.RangeMetaKey(roachpb.RKeyMin.Next()),
			EndKey: keys.RangeMetaKey(roachpb.RKeyMax),
		},
	}
	util.SucceedsSoon(t, func() error {
		_, pErr := client.SendWrapped(context.Background(), rg1(store), &scanArgs)
		return pErr.GoError()
	})

	revScanArgs := func(key []byte, maxResults int32) *roachpb.RangeLookupRequest {
		return &roachpb.RangeLookupRequest{
			Span: roachpb.Span{
				Key: key,
			},
			MaxRanges: maxResults,
			Reverse:   true,
		}

	}

	// Test cases.
	testCases := []struct {
		request     *roachpb.RangeLookupRequest
		expected    []roachpb.RangeDescriptor
		expectedPre []roachpb.RangeDescriptor
	}{
		// Test key in the middle of the range.
		{
			request: revScanArgs(keys.RangeMetaKey(roachpb.RKey("f")), 2),
			// ["e","g") and ["c","e").
			expected: []roachpb.RangeDescriptor{
				{StartKey: roachpb.RKey("e"), EndKey: roachpb.RKey("g")},
			},
			expectedPre: []roachpb.RangeDescriptor{
				{StartKey: roachpb.RKey("c"), EndKey: roachpb.RKey("e")},
			},
		},
		// Test key in the end key of the range.
		{
			request: revScanArgs(keys.RangeMetaKey(roachpb.RKey("g")), 3),
			// ["e","g"), ["c","e") and ["a","c").
			expected: []roachpb.RangeDescriptor{
				{StartKey: roachpb.RKey("e"), EndKey: roachpb.RKey("g")},
			},
			expectedPre: []roachpb.RangeDescriptor{
				{StartKey: roachpb.RKey("c"), EndKey: roachpb.RKey("e")},
				{StartKey: roachpb.RKey("a"), EndKey: roachpb.RKey("c")},
			},
		},
		{
			request: revScanArgs(keys.RangeMetaKey(roachpb.RKey("e")), 2),
			// ["c","e") and ["a","c").
			expected: []roachpb.RangeDescriptor{
				{StartKey: roachpb.RKey("c"), EndKey: roachpb.RKey("e")},
			},
			expectedPre: []roachpb.RangeDescriptor{
				{StartKey: roachpb.RKey("a"), EndKey: roachpb.RKey("c")},
			},
		},
		// Test Meta2KeyMax.
		{
			request: revScanArgs(keys.Meta2KeyMax, 2),
			// ["e","g") and ["g","\xff\xff")
			expected: []roachpb.RangeDescriptor{
				{StartKey: roachpb.RKey("g"), EndKey: roachpb.RKey("\xff\xff")},
			},
			expectedPre: []roachpb.RangeDescriptor{
				{StartKey: roachpb.RKey("e"), EndKey: roachpb.RKey("g")},
			},
		},
		// Test Meta1KeyMax.
		{
//.........這裏部分代碼省略.........

func meta(k roachpb.RKey) (roachpb.RKey, error) {
	return keys.Addr(keys.RangeMetaKey(k))
}