github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/pkg/upstream/topo.go (about)

     1  // Copyright 2024 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package upstream
    15  
    16  import (
    17  	"context"
    18  	"strconv"
    19  	"strings"
    20  	"time"
    21  
    22  	"github.com/pingcap/log"
    23  	"github.com/pingcap/tidb-dashboard/util/distro"
    24  	"github.com/pingcap/tidb-dashboard/util/netutil"
    25  	"github.com/pingcap/tidb/pkg/domain/infosync"
    26  	"github.com/pingcap/tiflow/pkg/errors"
    27  	clientv3 "go.etcd.io/etcd/client/v3"
    28  	"go.uber.org/zap"
    29  )
    30  
    31  const (
    32  	// topologyTiCDC is /topology/ticdc/{clusterID}/{ip:port}.
    33  	topologyTiCDC = "/topology/ticdc/%s/%s"
    34  	// topologyTiDB is /topology/tidb/{ip:port}.
    35  	// Refer to https://github.com/pingcap/tidb/blob/release-7.5/pkg/domain/infosync/info.go#L78-L79.
    36  	topologyTiDB    = infosync.TopologyInformationPath
    37  	topologyTiDBTTL = infosync.TopologySessionTTL
    38  	// defaultTimeout is the default timeout for etcd and mysql operations.
    39  	defaultTimeout = time.Second * 2
    40  )
    41  
    42  type tidbInstance struct {
    43  	IP   string
    44  	Port uint
    45  }
    46  
    47  // fetchTiDBTopology parses the TiDB topology from etcd.
    48  func fetchTiDBTopology(ctx context.Context, etcdClient *clientv3.Client) ([]tidbInstance, error) {
    49  	ctx2, cancel := context.WithTimeout(ctx, defaultTimeout)
    50  	defer cancel()
    51  
    52  	resp, err := etcdClient.Get(ctx2, topologyTiDB, clientv3.WithPrefix())
    53  	if err != nil {
    54  		return nil, errors.ErrPDEtcdAPIError.Wrap(err)
    55  	}
    56  
    57  	nodesAlive := make(map[string]struct{}, len(resp.Kvs))
    58  	nodesInfo := make(map[string]*tidbInstance, len(resp.Kvs))
    59  
    60  	for _, kv := range resp.Kvs {
    61  		key := string(kv.Key)
    62  		if !strings.HasPrefix(key, topologyTiDB) {
    63  			continue
    64  		}
    65  		// remainingKey looks like `ip:port/info` or `ip:port/ttl`.
    66  		remainingKey := strings.TrimPrefix(key[len(topologyTiDB):], "/")
    67  		keyParts := strings.Split(remainingKey, "/")
    68  		if len(keyParts) != 2 {
    69  			log.Warn("Ignored invalid topology key", zap.String("component", distro.R().TiDB), zap.String("key", key))
    70  			continue
    71  		}
    72  
    73  		switch keyParts[1] {
    74  		case "info":
    75  			address := keyParts[0]
    76  			hostname, port, err := netutil.ParseHostAndPortFromAddress(address)
    77  			if err != nil {
    78  				log.Warn("Ignored invalid tidb topology info entry",
    79  					zap.String("key", key),
    80  					zap.String("value", string(kv.Value)),
    81  					zap.Error(err))
    82  				continue
    83  			}
    84  			nodesInfo[keyParts[0]] = &tidbInstance{
    85  				IP:   hostname,
    86  				Port: port,
    87  			}
    88  		case "ttl":
    89  			alive, err := parseTiDBAliveness(kv.Value)
    90  			if !alive || err != nil {
    91  				log.Warn("Ignored invalid tidb topology TTL entry",
    92  					zap.String("key", key),
    93  					zap.String("value", string(kv.Value)),
    94  					zap.Error(err))
    95  				continue
    96  			}
    97  			nodesAlive[keyParts[0]] = struct{}{}
    98  		}
    99  	}
   100  
   101  	nodes := make([]tidbInstance, 0)
   102  	for addr, info := range nodesInfo {
   103  		if _, ok := nodesAlive[addr]; ok {
   104  			nodes = append(nodes, *info)
   105  		}
   106  	}
   107  	return nodes, nil
   108  }
   109  
   110  func parseTiDBAliveness(value []byte) (bool, error) {
   111  	unixTimestampNano, err := strconv.ParseUint(string(value), 10, 64)
   112  	if err != nil {
   113  		return false, errors.ErrUnmarshalFailed.Wrap(err)
   114  	}
   115  	t := time.Unix(0, int64(unixTimestampNano))
   116  	if time.Since(t) > topologyTiDBTTL*time.Second {
   117  		return false, nil
   118  	}
   119  	return true, nil
   120  }