Struct RegionAliveKeeper 

pub struct RegionAliveKeeper {
    region_server: RegionServer,
    tasks: Arc<Mutex<HashMap<RegionId, Arc<CountdownTaskHandle>>>>,
    heartbeat_interval_millis: u64,
    started: Arc<AtomicBool>,
    epoch: Instant,
    countdown_task_handler_ext: Option<CountdownTaskHandlerExtRef>,
}

RegionAliveKeeper manages all CountdownTaskHandles.

RegionAliveKeeper starts a CountdownTask for each region. When the deadline is reached, the status of region be set to “readonly”, ensures there is no side-effect in the entity system.

The deadline is controlled by the meta server. Datanode will send its opened regions info to meta sever via heartbeat. If the meta server decides some region could be resided in this Datanode, it will renew the lease of region, a deadline of CountdownTask will be reset.

Fields

region_server: RegionServer

tasks: Arc<Mutex<HashMap<RegionId, Arc<CountdownTaskHandle>>>>

heartbeat_interval_millis: u64

started: Arc<AtomicBool>

epoch: Instant

The epoch when RegionAliveKeeper is created. It’s used to get a monotonically non-decreasing elapsed time when submitting heartbeats to the meta server (because [Instant] is monotonically non-decreasing). The heartbeat requests will carry the duration since this epoch, and the duration acts like an “invariant point” for region’s keep alive lease.

countdown_task_handler_ext: Option<CountdownTaskHandlerExtRef>

Implementations

impl RegionAliveKeeper

pub fn new( region_server: RegionServer, countdown_task_handler_ext: Option<CountdownTaskHandlerExtRef>, heartbeat_interval_millis: u64, ) -> Self

Returns an empty RegionAliveKeeper.

async fn find_handle( &self, region_id: RegionId, ) -> Option<Arc<CountdownTaskHandle>>

pub async fn register_region(&self, region_id: RegionId)

Add the countdown task for a specific region. It will be ignored if the task exists.

pub async fn deregister_region(&self, region_id: RegionId)

Removes the countdown task for a specific region.

async fn renew_region_leases( &self, regions: &[GrantedRegion], deadline: Instant, )

Renews the lease of regions to deadline.

async fn close_staled_region(&self, region_id: RegionId)

async fn close_staled_regions(&self, regions: &[u64])

Closes staled regions.

pub async fn start( self: &Arc<Self>, event_receiver: Option<RegionServerEventReceiver>, ) -> Result<()>

pub fn epoch(&self) -> Instant

Trait Implementations

impl HeartbeatResponseHandler for RegionAliveKeeper

fn is_acceptable(&self, ctx: &HeartbeatResponseHandlerContext) -> bool

fn handle<'life0, 'life1, 'async_trait>( &'life0 self, ctx: &'life1 mut HeartbeatResponseHandlerContext, ) -> Pin<Box<dyn Future<Output = Result<HandleControl>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,