Associate events in db before queueing them to send (#2833)

Fixes a race condition between sending federation events and having them
fully associated in the database.
This commit is contained in:
devonh 2022-10-26 16:35:01 +00:00 committed by GitHub
parent a74aea0714
commit 97491a174b
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 60 additions and 34 deletions

View File

@ -76,21 +76,25 @@ func (oq *destinationQueue) sendEvent(event *gomatrixserverlib.HeaderedEvent, re
return
}
// If there's room in memory to hold the event then add it to the
// list.
oq.pendingMutex.Lock()
if len(oq.pendingPDUs) < maxPDUsInMemory {
oq.pendingPDUs = append(oq.pendingPDUs, &queuedPDU{
pdu: event,
receipt: receipt,
})
} else {
oq.overflowed.Store(true)
}
oq.pendingMutex.Unlock()
// Check if the destination is blacklisted. If it isn't then wake
// up the queue.
if !oq.statistics.Blacklisted() {
// If there's room in memory to hold the event then add it to the
// list.
oq.pendingMutex.Lock()
if len(oq.pendingPDUs) < maxPDUsInMemory {
oq.pendingPDUs = append(oq.pendingPDUs, &queuedPDU{
pdu: event,
receipt: receipt,
})
} else {
oq.overflowed.Store(true)
}
oq.pendingMutex.Unlock()
if !oq.backingOff.Load() {
oq.wakeQueueAndNotify()
if !oq.backingOff.Load() {
oq.wakeQueueAndNotify()
}
}
}
@ -103,21 +107,25 @@ func (oq *destinationQueue) sendEDU(event *gomatrixserverlib.EDU, receipt *share
return
}
// If there's room in memory to hold the event then add it to the
// list.
oq.pendingMutex.Lock()
if len(oq.pendingEDUs) < maxEDUsInMemory {
oq.pendingEDUs = append(oq.pendingEDUs, &queuedEDU{
edu: event,
receipt: receipt,
})
} else {
oq.overflowed.Store(true)
}
oq.pendingMutex.Unlock()
// Check if the destination is blacklisted. If it isn't then wake
// up the queue.
if !oq.statistics.Blacklisted() {
// If there's room in memory to hold the event then add it to the
// list.
oq.pendingMutex.Lock()
if len(oq.pendingEDUs) < maxEDUsInMemory {
oq.pendingEDUs = append(oq.pendingEDUs, &queuedEDU{
edu: event,
receipt: receipt,
})
} else {
oq.overflowed.Store(true)
}
oq.pendingMutex.Unlock()
if !oq.backingOff.Load() {
oq.wakeQueueAndNotify()
if !oq.backingOff.Load() {
oq.wakeQueueAndNotify()
}
}
}

View File

@ -247,9 +247,10 @@ func (oqs *OutgoingQueues) SendEvent(
return fmt.Errorf("sendevent: oqs.db.StoreJSON: %w", err)
}
destQueues := make([]*destinationQueue, 0, len(destmap))
for destination := range destmap {
if queue := oqs.getQueue(destination); queue != nil && !queue.statistics.Blacklisted() {
queue.sendEvent(ev, nid)
if queue := oqs.getQueue(destination); queue != nil {
destQueues = append(destQueues, queue)
} else {
delete(destmap, destination)
}
@ -267,6 +268,14 @@ func (oqs *OutgoingQueues) SendEvent(
return err
}
// NOTE : PDUs should be associated with destinations before sending
// them, otherwise this is technically a race.
// If the send completes before they are associated then they won't
// get properly cleaned up in the database.
for _, queue := range destQueues {
queue.sendEvent(ev, nid)
}
return nil
}
@ -335,20 +344,21 @@ func (oqs *OutgoingQueues) SendEDU(
return fmt.Errorf("sendevent: oqs.db.StoreJSON: %w", err)
}
destQueues := make([]*destinationQueue, 0, len(destmap))
for destination := range destmap {
if queue := oqs.getQueue(destination); queue != nil && !queue.statistics.Blacklisted() {
queue.sendEDU(e, nid)
if queue := oqs.getQueue(destination); queue != nil {
destQueues = append(destQueues, queue)
} else {
delete(destmap, destination)
}
}
// Create a database entry that associates the given PDU NID with
// this destination queue. We'll then be able to retrieve the PDU
// these destination queues. We'll then be able to retrieve the PDU
// later.
if err := oqs.db.AssociateEDUWithDestinations(
oqs.process.Context(),
destmap, // the destination server name
destmap, // the destination server names
nid, // NIDs from federationapi_queue_json table
e.Type,
nil, // this will use the default expireEDUTypes map
@ -357,6 +367,14 @@ func (oqs *OutgoingQueues) SendEDU(
return err
}
// NOTE : EDUs should be associated with destinations before sending
// them, otherwise this is technically a race.
// If the send completes before they are associated then they won't
// get properly cleaned up in the database.
for _, queue := range destQueues {
queue.sendEDU(e, nid)
}
return nil
}