Enum MigrationCheckpointPayload 

pub enum MigrationCheckpointPayload {
    AddLearner {
        vshard_id: u32,
        source_node: u64,
        target_node: u64,
        source_group: u64,
        write_pause_budget_us: u64,
        started_at_hlc: Hlc,
    },
    CatchUp {
        vshard_id: u32,
        learner_log_index_at_add: u64,
    },
    PromoteLearner {
        vshard_id: u32,
        target_node: u64,
        source_group: u64,
    },
    LeadershipTransfer {
        vshard_id: u32,
        target_is_voter: bool,
        new_leader_node_id: u64,
        source_group: u64,
    },
    Cutover {
        vshard_id: u32,
        new_leader_node_id: u64,
        source_group: u64,
    },
    Complete {
        vshard_id: u32,
        actual_pause_us: u64,
        ghost_stub_installed: bool,
    },
}

Payload written to the metadata Raft group at each phase boundary.

Each variant carries enough information to resume the migration from scratch if the coordinator crashes between two phases.

Variants

AddLearner

Written just before propose_conf_change(AddLearner).

Fields

vshard_id: u32

source_node: u64

target_node: u64

source_group: u64

write_pause_budget_us: u64

started_at_hlc: Hlc

CatchUp

Written just after AddLearner conf-change commits.

Fields

vshard_id: u32

learner_log_index_at_add: u64

Log index at which AddLearner committed. The resuming coordinator uses this to skip re-proposing AddLearner if the learner is already present in the group.

PromoteLearner

Written just after PromoteLearner conf-change commits.

Fields

vshard_id: u32

target_node: u64

source_group: u64

LeadershipTransfer

Written just before propose_and_wait(LeadershipTransfer).

Fields

vshard_id: u32

target_is_voter: bool

Whether PromoteLearner has already committed.

new_leader_node_id: u64

source_group: u64

Cutover

Written after propose_and_wait(LeadershipTransfer) returns success (cut-over committed).

Fields

vshard_id: u32

new_leader_node_id: u64

source_group: u64

Complete

Written after the ghost stub is installed and save_ghosts succeeds.

Fields

vshard_id: u32

actual_pause_us: u64

ghost_stub_installed: bool

Implementations

impl MigrationCheckpointPayload

pub fn phase_tag(&self) -> MigrationPhaseTag

Returns the phase tag matching this payload variant.

pub fn to_bytes(&self) -> Result<Vec<u8>>

Encode as zerompk bytes for CRC32C computation.

pub fn crc32c(&self) -> Result<u32>

Compute the CRC32C of the encoded payload bytes.

Trait Implementations

impl Clone for MigrationCheckpointPayload

fn clone(&self) -> MigrationCheckpointPayload

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MigrationCheckpointPayload

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MigrationCheckpointPayload

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'__msgpack_de> FromMessagePack<'__msgpack_de> for MigrationCheckpointPayload

fn read<R: Read<'__msgpack_de>>(reader: &mut R) -> Result<Self, Error>

where Self: Sized,

Reads the MessagePack representation of this value from the provided reader.

impl PartialEq for MigrationCheckpointPayload

fn eq(&self, other: &MigrationCheckpointPayload) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for MigrationCheckpointPayload

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl ToMessagePack for MigrationCheckpointPayload

fn write<W: Write>(&self, writer: &mut W) -> Result<(), Error>

Writes the MessagePack representation of this value into the provided writer.

impl Eq for MigrationCheckpointPayload

impl StructuralPartialEq for MigrationCheckpointPayload