octoleo/gh-ost
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge pull request #76 from github/cut-over-no-throttle

Browse Source 
not throttling during cut-over operation
This commit is contained in:
Shlomi Noach 2016-06-21 09:23:23 +02:00 committed by GitHub
commit dc8d27466c
1 changed files with 17 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
go/logic/migrator.go
View File

@ -65,6 +65,7 @@ type Migrator struct {
rowCopyCompleteFlag int64 rowCopyCompleteFlag int64
allEventsUpToLockProcessedInjectedFlag int64 allEventsUpToLockProcessedInjectedFlag int64
inCutOverCriticalActionFlag int64
cleanupImminentFlag int64 cleanupImminentFlag int64
// copyRowsQueue should not be buffered; if buffered some non-damaging but // copyRowsQueue should not be buffered; if buffered some non-damaging but
// excessive work happens at the end of the iteration as new copy-jobs arrive befroe realizing the copy is complete // excessive work happens at the end of the iteration as new copy-jobs arrive befroe realizing the copy is complete
@ -414,6 +415,7 @@ func (this *Migrator) Migrate() (err error) {
this.consumeRowCopyComplete() this.consumeRowCopyComplete()
log.Infof("Row copy complete") log.Infof("Row copy complete")
this.printStatus(ForcePrintStatusRule) this.printStatus(ForcePrintStatusRule)
this.migrationContext.MarkPointOfInterest()
if err := this.cutOver(); err != nil { if err := this.cutOver(); err != nil {
return err return err
@ -507,6 +509,9 @@ func (this *Migrator) waitForEventsUpToLock() (err error) {
// There is a point in time where the "original" table does not exist and queries are non-blocked // There is a point in time where the "original" table does not exist and queries are non-blocked
// and failing. // and failing.
func (this *Migrator) cutOverTwoStep() (err error) { func (this *Migrator) cutOverTwoStep() (err error) {
atomic.StoreInt64(&this.inCutOverCriticalActionFlag, 1)
defer atomic.StoreInt64(&this.inCutOverCriticalActionFlag, 0)
if err := this.retryOperation(this.applier.LockOriginalTable); err != nil { if err := this.retryOperation(this.applier.LockOriginalTable); err != nil {
return err return err
} }
@ -531,6 +536,9 @@ func (this *Migrator) cutOverTwoStep() (err error) {
// is being locked until swapped, hence DML queries being locked and unaware of the cut-over. // is being locked until swapped, hence DML queries being locked and unaware of the cut-over.
// In the worst case, there will ba a minor outage, where the original table would not exist. // In the worst case, there will ba a minor outage, where the original table would not exist.
func (this *Migrator) safeCutOver() (err error) { func (this *Migrator) safeCutOver() (err error) {
atomic.StoreInt64(&this.inCutOverCriticalActionFlag, 1)
defer atomic.StoreInt64(&this.inCutOverCriticalActionFlag, 0)
okToUnlockTable := make(chan bool, 2) okToUnlockTable := make(chan bool, 2)
originalTableRenamed := make(chan error, 1) originalTableRenamed := make(chan error, 1)
defer func() { defer func() {
@ -1102,7 +1110,15 @@ func (this *Migrator) executeWriteFuncs() error {
return nil return nil
} }
for { for {
this.throttle(nil) if atomic.LoadInt64(&this.inCutOverCriticalActionFlag) == 0 {
// we don't throttle when cutting over. We _do_ throttle:
// - during copy phase
// - just before cut-over
// - in between cut-over retries
this.throttle(nil)
// When cutting over, we need to be aggressive. Cut-over holds table locks.
// We need to release those asap.
}
// We give higher priority to event processing, then secondary priority to // We give higher priority to event processing, then secondary priority to
// rowcopy // rowcopy
select { select {