s3

Documentation

Index

• Constants
• type Replica
  • func NewReplica(db *litestream.DB, name string) *Replica
  • func (r *Replica) CalcPos(ctx context.Context, generation string) (pos litestream.Pos, err error)
  • func (r *Replica) DB() *litestream.DB
  • func (r *Replica) EnforceRetention(ctx context.Context) (err error)
  • func (r *Replica) GenerationDir(generation string) string
  • func (r *Replica) GenerationStats(ctx context.Context, generation string) (stats litestream.GenerationStats, err error)
  • func (r *Replica) Generations(ctx context.Context) ([]string, error)
  • func (r *Replica) Init(ctx context.Context) (err error)
  • func (r *Replica) LastPos() litestream.Pos
  • func (r *Replica) MaxSnapshotIndex(generation string) (int, error)
  • func (r *Replica) Name() string
  • func (r *Replica) SnapshotDir(generation string) string
  • func (r *Replica) SnapshotPath(generation string, index int) string
  • func (r *Replica) SnapshotReader(ctx context.Context, generation string, index int) (io.ReadCloser, error)
  • func (r *Replica) Snapshots(ctx context.Context) ([]*litestream.SnapshotInfo, error)
  • func (r *Replica) Start(ctx context.Context)
  • func (r *Replica) Stop()
  • func (r *Replica) Sync(ctx context.Context) (err error)
  • func (r *Replica) Type() string
  • func (r *Replica) WALDir(generation string) string
  • func (r *Replica) WALReader(ctx context.Context, generation string, index int) (io.ReadCloser, error)
  • func (r *Replica) WALs(ctx context.Context) ([]*litestream.WALInfo, error)

Constants

const (
	DefaultSyncInterval = 10 * time.Second

	DefaultRetention = 24 * time.Hour

	DefaultRetentionCheckInterval = 1 * time.Hour
)

S3 replica default settings.

const MaxKeys = 1000

MaxKeys is the number of keys S3 can operate on per batch.

Types

type Replica

type Replica struct {

	// AWS authentication keys.
	AccessKeyID     string
	SecretAccessKey string

	// S3 bucket information
	Region string
	Bucket string
	Path   string

	// Time between syncs with the shadow WAL.
	SyncInterval time.Duration

	// Time to keep snapshots and related WAL files.
	// Database is snapshotted after interval and older WAL files are discarded.
	Retention time.Duration

	// Time between retention checks.
	RetentionCheckInterval time.Duration

	// Time between validation checks.
	ValidationInterval time.Duration

	// If true, replica monitors database for changes automatically.
	// Set to false if replica is being used synchronously (such as in tests).
	MonitorEnabled bool
	// contains filtered or unexported fields
}

Replica is a replica that replicates a DB to an S3 bucket.

func NewReplica

func NewReplica(db *litestream.DB, name string) *Replica

NewReplica returns a new instance of Replica.

func (*Replica) CalcPos

func (r *Replica) CalcPos(ctx context.Context, generation string) (pos litestream.Pos, err error)

CalcPos returns the position for the replica for the current generation. Returns a zero value if there is no active generation.

func (*Replica) DB

func (r *Replica) DB() *litestream.DB

DB returns the parent database reference.

func (*Replica) EnforceRetention

func (r *Replica) EnforceRetention(ctx context.Context) (err error)

EnforceRetention forces a new snapshot once the retention interval has passed. Older snapshots and WAL files are then removed.

func (*Replica) GenerationDir

func (r *Replica) GenerationDir(generation string) string

GenerationDir returns the path to a generation's root directory.

func (*Replica) GenerationStats

func (r *Replica) GenerationStats(ctx context.Context, generation string) (stats litestream.GenerationStats, err error)

GenerationStats returns stats for a generation.

func (*Replica) Generations

func (r *Replica) Generations(ctx context.Context) ([]string, error)

Generations returns a list of available generation names.

func (*Replica) Init

func (r *Replica) Init(ctx context.Context) (err error)

Init initializes the connection to S3. No-op if already initialized.

func (*Replica) LastPos

func (r *Replica) LastPos() litestream.Pos

LastPos returns the last successfully replicated position.

func (*Replica) MaxSnapshotIndex

func (r *Replica) MaxSnapshotIndex(generation string) (int, error)

MaxSnapshotIndex returns the highest index for the snapshots.

func (*Replica) Name

func (r *Replica) Name() string

Name returns the name of the replica. Returns the type if no name set.

func (*Replica) SnapshotDir

func (r *Replica) SnapshotDir(generation string) string

SnapshotDir returns the path to a generation's snapshot directory.

func (*Replica) SnapshotPath

func (r *Replica) SnapshotPath(generation string, index int) string

SnapshotPath returns the path to a snapshot file.

func (*Replica) SnapshotReader

func (r *Replica) SnapshotReader(ctx context.Context, generation string, index int) (io.ReadCloser, error)

SnapshotReader returns a reader for snapshot data at the given generation/index.

func (*Replica) Snapshots

func (r *Replica) Snapshots(ctx context.Context) ([]*litestream.SnapshotInfo, error)

Snapshots returns a list of available snapshots in the replica.

func (*Replica) Start

func (r *Replica) Start(ctx context.Context)

Start starts replication for a given generation.

func (*Replica) Stop

func (r *Replica) Stop()

Stop cancels any outstanding replication and blocks until finished.

func (*Replica) Sync

func (r *Replica) Sync(ctx context.Context) (err error)

Sync replays data from the shadow WAL and uploads it to S3.

func (*Replica) Type

func (r *Replica) Type() string

Type returns the type of replica.

func (*Replica) WALDir

func (r *Replica) WALDir(generation string) string

WALDir returns the path to a generation's WAL directory

func (*Replica) WALReader

func (r *Replica) WALReader(ctx context.Context, generation string, index int) (io.ReadCloser, error)

WALReader returns a reader for WAL data at the given index. Returns os.ErrNotExist if no matching index is found.

func (*Replica) WALs

func (r *Replica) WALs(ctx context.Context) ([]*litestream.WALInfo, error)

WALs returns a list of available WAL files in the replica.