|
| 1 | +package node_hints |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "fmt" |
| 6 | + "log" |
| 7 | + "math/rand" |
| 8 | + "slices" |
| 9 | + "slo/internal/generator" |
| 10 | + "sync/atomic" |
| 11 | + "time" |
| 12 | + |
| 13 | + "github.com/ydb-platform/ydb-go-sdk/v3" |
| 14 | + "github.com/ydb-platform/ydb-go-sdk/v3/table" |
| 15 | + "github.com/ydb-platform/ydb-go-sdk/v3/table/options" |
| 16 | + "github.com/ydb-platform/ydb-go-sdk/v3/table/types" |
| 17 | +) |
| 18 | + |
| 19 | +func describeTable(ctx context.Context, driver *ydb.Driver, tableName string) (desc options.Description, err error) { |
| 20 | + err = driver.Table().Do(ctx, |
| 21 | + func(ctx context.Context, session table.Session) (err error) { |
| 22 | + desc, err = session.DescribeTable(ctx, tableName, |
| 23 | + options.WithTableStats(), |
| 24 | + options.WithPartitionStats(), |
| 25 | + options.WithShardKeyBounds(), |
| 26 | + options.WithShardNodesInfo(), |
| 27 | + ) |
| 28 | + return err |
| 29 | + }, |
| 30 | + table.WithIdempotent(), |
| 31 | + ) |
| 32 | + return desc, err |
| 33 | +} |
| 34 | + |
| 35 | +type NodeSelector struct { |
| 36 | + LowerBounds []uint64 |
| 37 | + UpperBounds []uint64 |
| 38 | + NodeIDs []uint32 |
| 39 | +} |
| 40 | + |
| 41 | +func extractKey(v types.Value, side int) (uint64, error) { |
| 42 | + if types.IsNull(v) { |
| 43 | + if side == LEFT { |
| 44 | + return 0, nil |
| 45 | + } else { |
| 46 | + return ^uint64(0), nil |
| 47 | + } |
| 48 | + } |
| 49 | + parts, err := types.TupleItems(v) |
| 50 | + if err != nil { |
| 51 | + return 0, fmt.Errorf("extract tuple: %w", err) |
| 52 | + } |
| 53 | + |
| 54 | + var res uint64 |
| 55 | + if err := types.CastTo(parts[0], &res); err != nil { |
| 56 | + return 0, fmt.Errorf("cast to uint64: %w", err) |
| 57 | + } |
| 58 | + |
| 59 | + return res, nil |
| 60 | +} |
| 61 | + |
| 62 | +const ( |
| 63 | + LEFT = iota |
| 64 | + RIGHT = iota |
| 65 | +) |
| 66 | + |
| 67 | +func MakeNodeSelector(ctx context.Context, driver *ydb.Driver, tableName string) (*NodeSelector, error) { |
| 68 | + dsc, err := describeTable(ctx, driver, tableName) |
| 69 | + |
| 70 | + if err != nil { |
| 71 | + return nil, err |
| 72 | + } |
| 73 | + |
| 74 | + s := NodeSelector{} |
| 75 | + |
| 76 | + for _, kr := range dsc.KeyRanges { |
| 77 | + l, err := extractKey(kr.From, LEFT) |
| 78 | + if err != nil { |
| 79 | + return nil, err |
| 80 | + } |
| 81 | + s.LowerBounds = append(s.LowerBounds, l) |
| 82 | + r, err := extractKey(kr.To, RIGHT) |
| 83 | + if err != nil { |
| 84 | + return nil, err |
| 85 | + } |
| 86 | + s.UpperBounds = append(s.UpperBounds, r) |
| 87 | + } |
| 88 | + |
| 89 | + for i := range len(s.UpperBounds) - 1 { |
| 90 | + if s.UpperBounds[i] >= s.UpperBounds[i+1] { |
| 91 | + for _, b := range s.UpperBounds { |
| 92 | + log.Println(b) |
| 93 | + } |
| 94 | + log.Fatalf("boundaries are not sorted") |
| 95 | + } |
| 96 | + } |
| 97 | + |
| 98 | + for _, ps := range dsc.Stats.PartitionStats { |
| 99 | + s.NodeIDs = append(s.NodeIDs, ps.LeaderNodeID) |
| 100 | + } |
| 101 | + return &s, nil |
| 102 | +} |
| 103 | + |
| 104 | +func (s *NodeSelector) findNodeID(key uint64) uint32 { |
| 105 | + idx, found := slices.BinarySearch(s.UpperBounds, key) |
| 106 | + if found { |
| 107 | + idx++ |
| 108 | + } |
| 109 | + return s.NodeIDs[idx] |
| 110 | +} |
| 111 | + |
| 112 | +func (s *NodeSelector) WithNodeHint(ctx context.Context, key uint64) context.Context { |
| 113 | + if s == nil || len(s.NodeIDs) == 0 { |
| 114 | + return ctx |
| 115 | + } |
| 116 | + return ydb.WithPreferredNodeID(ctx, s.findNodeID(key)) |
| 117 | +} |
| 118 | + |
| 119 | +func (s *NodeSelector) GeneratePartitionKey(partitionId uint64) uint64 { |
| 120 | + l := s.UpperBounds[partitionId] - s.LowerBounds[partitionId] |
| 121 | + return s.LowerBounds[partitionId] + rand.Uint64()%l |
| 122 | +} |
| 123 | + |
| 124 | +func RunUpdates(ctx context.Context, driver *ydb.Driver, tableName string, frequency time.Duration) (*atomic.Pointer[NodeSelector], error) { |
| 125 | + var ns atomic.Pointer[NodeSelector] |
| 126 | + updateSelector := func() error { |
| 127 | + selector, err := MakeNodeSelector(ctx, driver, tableName) |
| 128 | + if err != nil { |
| 129 | + return err |
| 130 | + } |
| 131 | + ns.Store(selector) |
| 132 | + return nil |
| 133 | + } |
| 134 | + |
| 135 | + err := updateSelector() |
| 136 | + if err != nil { |
| 137 | + return nil, err |
| 138 | + } else { |
| 139 | + ticker := time.NewTicker(frequency) |
| 140 | + go func() { |
| 141 | + defer ticker.Stop() |
| 142 | + for { |
| 143 | + select { |
| 144 | + case <-ctx.Done(): |
| 145 | + return |
| 146 | + case <-ticker.C: |
| 147 | + err = updateSelector() |
| 148 | + if err != nil { |
| 149 | + log.Printf("node hints update error: %v\n", err) |
| 150 | + } |
| 151 | + } |
| 152 | + } |
| 153 | + }() |
| 154 | + } |
| 155 | + return &ns, nil |
| 156 | +} |
| 157 | + |
| 158 | +func (ns *NodeSelector) GetRandomNodeID(generator generator.Generator) (int, uint32) { |
| 159 | + r, err := generator.Generate() |
| 160 | + if err != nil { |
| 161 | + log.Panicf("GetRandomNodeID: generator.Generate failed: %v", err) |
| 162 | + } |
| 163 | + shift := r.ID % uint64(len(ns.NodeIDs)) |
| 164 | + for id, nodeID := range ns.NodeIDs { |
| 165 | + if id == int(shift) { |
| 166 | + return id, nodeID |
| 167 | + } |
| 168 | + } |
| 169 | + log.Panicf("GetRandomNodeID: no nodeID found for shift: %d", shift) |
| 170 | + return 0, 0 |
| 171 | +} |
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