Documentation
¶
Overview ¶
Package gc privodes TiDB GC related utilities.
Following graph shows how TiCDC manipulates GC safepoints.
```
┌───┐ ┌───┐ ┌──┐ ┌─────┐
│CLI│ │API│ │PD│ │Owner│
└─┬─┘ └─┬─┘ └┬─┘ └──┬──┘
│ │ │ │
╔═══════════╪═════╤════════╪═════════════╪════════════════════════╪════════════╗
║ "CLI OR API?" │ CLI │ │ │ ║
╟─────────────────┘ │ │ │ ║
║ │ service GC safepoint │ │ ║
║ │ "cdc-creating-<ID>" │ │ ║
║ │──────────────────────────>┌┴┐ │ ║
║ │ │ │ │ │ ║
║ │ Create changefeed │ │ │ ║
║ │──────────────────────────>│ │ │ ║
╠═══════════╪══════════════╪════════════╪═╪═══════════════════════╪════════════╣
║ API │ │ │ │ │ ║
║ │ │ Create changefeed API │ ║
║ │ │─────────────────────────────────────>│ ║
║ │ │ │ │ │ ║
║ │ │ │ │ service GC safepoint│ ║
║ │ │ │ │ "cdc-creating-<ID>" │ ║
║ │ │ │ ┌─┐ <──────────────────── ║
║ │ │ │ │ │ │ ║
║ │ │ │ │ │ Create changefeed │ ║
║ │ │ │ │ │ <──────────────────── ║
╚═══════════╪══════════════╪════════════╪═╪═╪═════════════════════╪════════════╝
│ │ │ │ │ │
│ │ │ │ │ │ ╔═════════════════╗
│ │ │ │ │ GC safepoint "ticdc"│ ║using the minimal║
│ │ │ │ │ <──────────────────── ║checkpoint among ║
│ │ │ │ │ │ ║all changefeeds ║
│ │ │ │ │ │ ╚═════════════════╝
│ │ │ │ │Remove GC safepoint │
│ │ │ │ │"cdc-creating-<ID>" │
│ │ └┬└─┘ <────────────────────
│ │ │ │
│ │ │ │────┐
│ │ │ │ │ Start changefeed
│ │ │ │<───┘
┌─┴─┐ ┌─┴─┐ ┌┴─┐ ┌──┴──┐
│CLI│ │API│ │PD│ │Owner│
└───┘ └───┘ └──┘ └─────┘
```
When CLI/API creates a changefeed, it registers a service GC safepoint "ticdc-creating-<ID>" to cover the gap between creating changefeed and handling changefeed.
TiCDC Owner removes the service GC safepoint after new changefeed checkpoint is included in the "ticdc" service GC safepoint.
Index ¶
- Constants
- func EnsureChangefeedStartTsSafety(ctx context.Context, pdCli pd.Client, gcServiceIDPrefix string, ...) error
- func InitMetrics(registry *prometheus.Registry)
- func RemoveServiceGCSafepoint(ctx context.Context, pdCli pd.Client, serviceID string) error
- func SetServiceGCSafepoint(ctx context.Context, pdCli pd.Client, serviceID string, TTL int64, ...) (minServiceGCTs uint64, err error)
- func UndoEnsureChangefeedStartTsSafety(ctx context.Context, pdCli pd.Client, gcServiceIDPrefix string, ...) error
- type Manager
- type MockPDClient
- func (m *MockPDClient) Close()
- func (m *MockPDClient) GetAllStores(ctx context.Context, opts ...pd.GetStoreOption) ([]*metapb.Store, error)
- func (m *MockPDClient) GetClusterID(ctx context.Context) uint64
- func (m *MockPDClient) GetTS(ctx context.Context) (int64, int64, error)
- func (m *MockPDClient) LoadGlobalConfig(ctx context.Context, names []string, configPath string) ([]pd.GlobalConfigItem, int64, error)
- func (m *MockPDClient) UpdateServiceGCSafePoint(ctx context.Context, serviceID string, ttl int64, safePoint uint64) (uint64, error)
Constants ¶
const ( // EnsureGCServiceCreating is a tag of GC service id for changefeed creation EnsureGCServiceCreating = "-creating-" // EnsureGCServiceResuming is a tag of GC service id for changefeed resumption EnsureGCServiceResuming = "-resuming-" // EnsureGCServiceInitializing is a tag of GC service id for changefeed initialization EnsureGCServiceInitializing = "-initializing-" )
Variables ¶
This section is empty.
Functions ¶
func EnsureChangefeedStartTsSafety ¶
func EnsureChangefeedStartTsSafety( ctx context.Context, pdCli pd.Client, gcServiceIDPrefix string, changefeedID model.ChangeFeedID, TTL int64, startTs uint64, ) error
EnsureChangefeedStartTsSafety checks if the startTs less than the minimum of service GC safepoint and this function will update the service GC to startTs
func InitMetrics ¶
func InitMetrics(registry *prometheus.Registry)
InitMetrics registers all metrics used gc manager
func RemoveServiceGCSafepoint ¶
RemoveServiceGCSafepoint removes a service safepoint from PD.
func SetServiceGCSafepoint ¶
func SetServiceGCSafepoint( ctx context.Context, pdCli pd.Client, serviceID string, TTL int64, safePoint uint64, ) (minServiceGCTs uint64, err error)
SetServiceGCSafepoint set a service safepoint to PD.
func UndoEnsureChangefeedStartTsSafety ¶
func UndoEnsureChangefeedStartTsSafety( ctx context.Context, pdCli pd.Client, gcServiceIDPrefix string, changefeedID model.ChangeFeedID, ) error
UndoEnsureChangefeedStartTsSafety cleans the service GC safepoint of a changefeed if something goes wrong after successfully calling EnsureChangefeedStartTsSafety().
Types ¶
type Manager ¶
type Manager interface {
// TryUpdateGCSafePoint tries to update TiCDC service GC safepoint.
// Manager may skip update when it thinks it is too frequent.
// Set `forceUpdate` to force Manager update.
TryUpdateGCSafePoint(ctx context.Context, checkpointTs model.Ts, forceUpdate bool) error
CheckStaleCheckpointTs(ctx context.Context, changefeedID model.ChangeFeedID, checkpointTs model.Ts) error
}
Manager is an interface for gc manager
type MockPDClient ¶
type MockPDClient struct {
pd.Client
ClusterID uint64
GetAllStoresFunc func(ctx context.Context, opts ...pd.GetStoreOption) ([]*metapb.Store, error)
UpdateServiceGCSafePointFunc func(ctx context.Context, serviceID string, ttl int64, safePoint uint64) (uint64, error)
}
MockPDClient mocks pd.Client to facilitate unit testing.
func (*MockPDClient) Close ¶
func (m *MockPDClient) Close()
Close implements pd.Client.Close() This method is used in some unit test cases.
func (*MockPDClient) GetAllStores ¶
func (m *MockPDClient) GetAllStores( ctx context.Context, opts ...pd.GetStoreOption, ) ([]*metapb.Store, error)
GetAllStores gets all stores from PD.
func (*MockPDClient) GetClusterID ¶
func (m *MockPDClient) GetClusterID(ctx context.Context) uint64
GetClusterID gets the cluster ID from PD.
func (*MockPDClient) LoadGlobalConfig ¶
func (m *MockPDClient) LoadGlobalConfig( ctx context.Context, names []string, configPath string, ) ([]pd.GlobalConfigItem, int64, error)
LoadGlobalConfig loads global config from PD.
func (*MockPDClient) UpdateServiceGCSafePoint ¶
func (m *MockPDClient) UpdateServiceGCSafePoint(ctx context.Context, serviceID string, ttl int64, safePoint uint64) (uint64, error)
UpdateServiceGCSafePoint implements pd.Client.UpdateServiceGCSafePoint.
Source Files