func replicaGCShouldQueueImpl(
now, lastCheck, lastActivity hlc.Timestamp, isCandidate bool,
) (bool, float64) {
timeout := ReplicaGCQueueInactivityThreshold
var priority float64
if isCandidate {
// If the range is a candidate (which happens if its former replica set
// ignores it), let it expire much earlier.
timeout = ReplicaGCQueueCandidateTimeout
priority++
} else if now.Less(lastCheck.Add(ReplicaGCQueueInactivityThreshold.Nanoseconds(), 0)) {
// Return false immediately if the previous check was less than the
// check interval in the past. Note that we don't do this is the
// replica is in candidate state, in which case we want to be more
// aggressive - a failed rebalance attempt could have checked this
// range, and candidate state suggests that a retry succeeded. See
// #7489.
return false, 0
}
shouldQ := lastActivity.Add(timeout.Nanoseconds(), 0).Less(now)
if !shouldQ {
return false, 0
}
return shouldQ, priority
}
// InitOrJoinRequest executes a RequestLease command asynchronously and returns a
// channel on which the result will be posted. If there's already a request in
// progress, we join in waiting for the results of that request.
// It is an error to call InitOrJoinRequest() while a request is in progress
// naming another replica as lease holder.
//
// replica is used to schedule and execute async work (proposing a RequestLease
// command). replica.mu is locked when delivering results, so calls from the
// replica happen either before or after a result for a pending request has
// happened.
//
// transfer needs to be set if the request represents a lease transfer (as
// opposed to an extension, or acquiring the lease when none is held).
//
// Note: Once this function gets a context to be used for cancellation, instead
// of replica.store.Stopper().ShouldQuiesce(), care will be needed for cancelling
// the Raft command, similar to replica.addWriteCmd.
func (p *pendingLeaseRequest) InitOrJoinRequest(
replica *Replica,
nextLeaseHolder roachpb.ReplicaDescriptor,
timestamp hlc.Timestamp,
startKey roachpb.Key,
transfer bool,
) <-chan *roachpb.Error {
if nextLease := p.RequestPending(); nextLease != nil {
if nextLease.Replica.ReplicaID == nextLeaseHolder.ReplicaID {
// Join a pending request asking for the same replica to become lease
// holder.
return p.JoinRequest()
}
llChan := make(chan *roachpb.Error, 1)
// We can't join the request in progress.
llChan <- roachpb.NewErrorf("request for different replica in progress "+
"(requesting: %+v, in progress: %+v)",
nextLeaseHolder.ReplicaID, nextLease.Replica.ReplicaID)
return llChan
}
llChan := make(chan *roachpb.Error, 1)
// No request in progress. Let's propose a Lease command asynchronously.
// TODO(tschottdorf): get duration from configuration, either as a
// config flag or, later, dynamically adjusted.
startStasis := timestamp.Add(int64(replica.store.ctx.rangeLeaseActiveDuration), 0)
expiration := startStasis.Add(int64(replica.store.Clock().MaxOffset()), 0)
reqSpan := roachpb.Span{
Key: startKey,
}
var leaseReq roachpb.Request
reqLease := roachpb.Lease{
Start: timestamp,
StartStasis: startStasis,
Expiration: expiration,
Replica: nextLeaseHolder,
}
if transfer {
leaseReq = &roachpb.TransferLeaseRequest{
Span: reqSpan,
Lease: reqLease,
}
} else {
leaseReq = &roachpb.RequestLeaseRequest{
Span: reqSpan,
Lease: reqLease,
}
}
if replica.store.Stopper().RunAsyncTask(func() {
// Propose a RequestLease command and wait for it to apply.
var execPErr *roachpb.Error
ba := roachpb.BatchRequest{}
ba.Timestamp = replica.store.Clock().Now()
ba.RangeID = replica.RangeID
ba.Add(leaseReq)
// Send lease request directly to raft in order to skip unnecessary
// checks from normal request machinery, (e.g. the command queue).
// Note that the command itself isn't traced, but usually the caller
// waiting for the result has an active Trace.
ch, _, err := replica.proposeRaftCommand(
replica.context(context.Background()), ba)
if err != nil {
execPErr = roachpb.NewError(err)
} else {
// If the command was committed, wait for the range to apply it.
select {
case c := <-ch:
if c.Err != nil {
if log.V(1) {
log.Infof("failed to acquire lease for replica %s: %s", replica.store, c.Err)
}
execPErr = c.Err
}
case <-replica.store.Stopper().ShouldQuiesce():
execPErr = roachpb.NewError(
replica.newNotLeaseHolderError(nil, replica.store.StoreID(), replica.Desc()))
}
}
// Send result of lease to all waiter channels.
replica.mu.Lock()
defer replica.mu.Unlock()
for i, llChan := range p.llChans {
// Don't send the same pErr object twice; this can lead to races. We could
// clone every time but it's more efficient to send pErr itself to one of
// the channels (the last one; if we send it earlier the race can still
// happen).
if i == len(p.llChans)-1 {
llChan <- execPErr
} else {
llChan <- protoutil.Clone(execPErr).(*roachpb.Error) // works with `nil`
}
}
p.llChans = p.llChans[:0]
p.nextLease = roachpb.Lease{}
}) != nil {
// We failed to start the asynchronous task. Send a blank NotLeaseHolderError
// back to indicate that we have no idea who the range lease holder might
// be; we've withdrawn from active duty.
llChan <- roachpb.NewError(
replica.newNotLeaseHolderError(nil, replica.store.StoreID(), replica.mu.state.Desc))
return llChan
}
p.llChans = append(p.llChans, llChan)
p.nextLease = reqLease
return llChan
}
