Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Owner: Fix gcttl bug (#1861) #1872

Merged
merged 8 commits into from
May 31, 2021
Merged

Owner: Fix gcttl bug (#1861) #1872

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
1fe503f
owner: fix bug : Can not create changefeed when start ts is less than…
asddongmen May 27, 2021
c673703
owner: update unit test
asddongmen May 27, 2021
592405a
owner: delete useless log
asddongmen May 27, 2021
816c14d
owner: Modify the way of obtaining pdGCSafePoint
asddongmen May 27, 2021
e850313
owner: add some comments
asddongmen May 28, 2021
13a6eeb
owner: Delete a redundant check
asddongmen May 28, 2021
a6af59d
owner: add some comments
asddongmen May 28, 2021
2b611bb
Merge branch 'release-5.0' into cherry-pick-1861-to-release-5.0
ti-chi-bot May 31, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
26 changes: 22 additions & 4 deletions cdc/owner.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -85,6 +85,15 @@ func (o *Owner) getMinGCSafePointCache(ctx context.Context) model.Ts {
return o.minGCSafePointCache.ts
}
o.minGCSafePointCache.ts = oracle.ComposeTS(physicalTs-(o.gcTTL*1000), logicalTs)

// o.pdGCSafePoint pd is the smallest gcSafePoint across all services.
// If tikv_gc_life_time > gcTTL, means that tikv_gc_safe_point < o.minGCSafePointCache.ts here.
// It also means that pd.pdGCSafePoint < o.minGCSafePointCache.ts here, we should use its value as the min value.
// This ensures that when tikv_gc_life_time > gcTTL , cdc will not advance the gcSafePoint.
if o.pdGCSafePoint < o.minGCSafePointCache.ts {
o.minGCSafePointCache.ts = o.pdGCSafePoint
}

o.minGCSafePointCache.lastUpdated = time.Now()
}
return o.minGCSafePointCache.ts
Expand Down Expand Up @@ -127,6 +136,8 @@ type Owner struct {
gcSafepointLastUpdate time.Time
// stores the ts obtained from PD and is updated every MinGCSafePointCacheUpdateInterval.
minGCSafePointCache minGCSafePointCacheEntry
// stores the actual gcSafePoint stored in pd
pdGCSafePoint model.Ts
// record last time that flushes all changefeeds' replication status
lastFlushChangefeeds time.Time
flushChangefeedInterval time.Duration
Expand Down Expand Up @@ -753,12 +764,18 @@ func (o *Owner) flushChangeFeedInfos(ctx context.Context) error {
if changefeed.status.CheckpointTs < gcSafePoint {
gcSafePoint = changefeed.status.CheckpointTs
}
// If changefeed's appliedCheckpoinTs < minGCSafePoint, it means this changefeed is stagnant.
// 1. If changefeed's appliedCheckpoinTs <= minGCSafePoint, it means this changefeed is stagnant.
// They are collected into this map, and then handleStaleChangeFeed() is called to deal with these stagnant changefeed.
// A changefeed will not enter the map twice, because in run(),
// handleAdminJob() will always be executed before flushChangeFeedInfos(),
// ensuring that the previous changefeed in staleChangeFeeds has been stopped and removed from o.changeFeeds.
if changefeed.status.CheckpointTs < minGCSafePoint {
// 2. We need the `<=` check here is because when a changefeed is stagnant, its checkpointTs will be updated to pd,
// and it would be the minimum gcSafePoint across all services.
// So as described above(line 92) minGCSafePoint = gcSafePoint = CheckpointTs would happens.
// In this case, if we check `<` here , this changefeed will not be put into staleChangeFeeds, and its checkpoints will be updated to pd again and again.
// This will cause the cdc's gcSafePoint never advance.
// If we check `<=` here, when we encounter the changefeed again, we will put it into staleChangeFeeds.
if changefeed.status.CheckpointTs <= minGCSafePoint {
staleChangeFeeds[id] = changefeed.status
}

Expand All @@ -781,10 +798,10 @@ func (o *Owner) flushChangeFeedInfos(ctx context.Context) error {
}

for _, status := range o.stoppedFeeds {
// If a stopped changefeed's CheckpoinTs < minGCSafePoint, means this changefeed is stagnant.
// If a stopped changefeed's CheckpoinTs <= minGCSafePoint, means this changefeed is stagnant.
// It should never be resumed. This part of the logic is in newChangeFeed()
// So here we can skip it.
if status.CheckpointTs < minGCSafePoint {
if status.CheckpointTs <= minGCSafePoint {
continue
}

Expand All @@ -810,6 +827,7 @@ func (o *Owner) flushChangeFeedInfos(ctx context.Context) error {
return cerror.ErrUpdateServiceSafepointFailed.Wrap(err)
}
} else {
o.pdGCSafePoint = actual
o.gcSafepointLastUpdate = time.Now()
}

Expand Down
112 changes: 88 additions & 24 deletions cdc/owner_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,8 @@ import (
"golang.org/x/sync/errgroup"
)

const TiKVGCLifeTime = 10 * 60 * time.Second // 10 min

type ownerSuite struct {
e *embed.Etcd
clientURL *url.URL
Expand Down Expand Up @@ -87,9 +89,10 @@ func (s *ownerSuite) TearDownTest(c *check.C) {

type mockPDClient struct {
pd.Client
invokeCounter int
mockSafePointLost bool
mockPDFailure bool
invokeCounter int
mockSafePointLost bool
mockPDFailure bool
mockTiKVGCLifeTime bool
}

func (m *mockPDClient) GetTS(ctx context.Context) (int64, int64, error) {
Expand All @@ -111,7 +114,10 @@ func (m *mockPDClient) UpdateServiceGCSafePoint(ctx context.Context, serviceID s
if m.mockPDFailure {
return 0, errors.New("injected PD failure")
}

if m.mockTiKVGCLifeTime {
Ts := oracle.GoTimeToTS(time.Now().Add(-TiKVGCLifeTime))
return Ts, nil
}
return safePoint, nil
}

Expand Down Expand Up @@ -186,18 +192,19 @@ func (s *ownerSuite) TestOwnerFlushChangeFeedInfosFailed(c *check.C) {
s.TearDownTest(c)
}

// Test whether the owner handles the stagnant task correctly, so that it can't block the update of gcSafePoint.
// If a changefeed is put into the stop queue due to stagnation, it can no longer affect the update of gcSafePoint.
// So we just need to test whether the stagnant changefeed is put into the stop queue.
func (s *ownerSuite) TestOwnerHandleStaleChangeFeed(c *check.C) {
defer testleak.AfterTest(c)()
// Test whether it is possible to successfully create a changefeed
// with startTs less than currentTs - gcTTL when tikv_gc_life_time is greater than gc-ttl
func (s *ownerSuite) TestTiKVGCLifeTimeLargeThanGCTTL(c *check.C) {
defer testleak.AfterTest(c)
mockPDCli := &mockPDClient{}
mockPDCli.mockTiKVGCLifeTime = true

changeFeeds := map[model.ChangeFeedID]*changeFeed{
"test_change_feed_1": {
info: &model.ChangeFeedInfo{State: model.StateNormal},
etcdCli: s.client,
status: &model.ChangeFeedStatus{
CheckpointTs: 1000,
CheckpointTs: oracle.GoTimeToTS(time.Now().Add(-6 * time.Second)),
},
targetTs: 2000,
ddlState: model.ChangeFeedSyncDML,
Expand All @@ -210,11 +217,59 @@ func (s *ownerSuite) TestOwnerHandleStaleChangeFeed(c *check.C) {
"capture_2": {},
},
},
"test_change_feed_2": {
}

session, err := concurrency.NewSession(s.client.Client.Unwrap(),
concurrency.WithTTL(config.GetDefaultServerConfig().CaptureSessionTTL))
c.Assert(err, check.IsNil)

mockOwner := Owner{
session: session,
pdClient: mockPDCli,
etcdClient: s.client,
lastFlushChangefeeds: time.Now(),
flushChangefeedInterval: 1 * time.Hour,
// gcSafepointLastUpdate: time.Now(),
gcTTL: 6, // 6 seconds
changeFeeds: changeFeeds,
cfRWriter: s.client,
stoppedFeeds: make(map[model.ChangeFeedID]*model.ChangeFeedStatus),
minGCSafePointCache: minGCSafePointCacheEntry{},
}

err = mockOwner.flushChangeFeedInfos(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockPDCli.invokeCounter, check.Equals, 1)

err = mockOwner.handleAdminJob(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockOwner.stoppedFeeds["test_change_feed_1"], check.IsNil)
c.Assert(mockOwner.changeFeeds["test_change_feed_1"].info.State, check.Equals, model.StateNormal)

time.Sleep(7 * time.Second) // wait for gcTTL time pass
err = mockOwner.flushChangeFeedInfos(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockPDCli.invokeCounter, check.Equals, 2)

err = mockOwner.handleAdminJob(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockOwner.stoppedFeeds["test_change_feed_1"], check.IsNil)

s.TearDownTest(c)
}

// Test whether the owner handles the stagnant task correctly, so that it can't block the update of gcSafePoint.
// If a changefeed is put into the stop queue due to stagnation, it can no longer affect the update of gcSafePoint.
// So we just need to test whether the stagnant changefeed is put into the stop queue.
func (s *ownerSuite) TestOwnerHandleStaleChangeFeed(c *check.C) {
defer testleak.AfterTest(c)()
mockPDCli := &mockPDClient{}
changeFeeds := map[model.ChangeFeedID]*changeFeed{
"test_change_feed_1": {
info: &model.ChangeFeedInfo{State: model.StateNormal},
etcdCli: s.client,
status: &model.ChangeFeedStatus{
CheckpointTs: oracle.EncodeTSO(oracle.GetPhysical(time.Now())),
CheckpointTs: 1000,
},
targetTs: 2000,
ddlState: model.ChangeFeedSyncDML,
Expand All @@ -227,11 +282,11 @@ func (s *ownerSuite) TestOwnerHandleStaleChangeFeed(c *check.C) {
"capture_2": {},
},
},
"test_change_feed_3": {
"test_change_feed_2": {
info: &model.ChangeFeedInfo{State: model.StateNormal},
etcdCli: s.client,
status: &model.ChangeFeedStatus{
CheckpointTs: 0,
CheckpointTs: oracle.EncodeTSO(oracle.GetPhysical(time.Now())),
},
targetTs: 2000,
ddlState: model.ChangeFeedSyncDML,
Expand All @@ -256,32 +311,41 @@ func (s *ownerSuite) TestOwnerHandleStaleChangeFeed(c *check.C) {
etcdClient: s.client,
lastFlushChangefeeds: time.Now(),
flushChangefeedInterval: 1 * time.Hour,
// gcSafepointLastUpdate: time.Now(),
gcTTL: 6, // 6 seconds
changeFeeds: changeFeeds,
cfRWriter: s.client,
stoppedFeeds: make(map[model.ChangeFeedID]*model.ChangeFeedStatus),
minGCSafePointCache: minGCSafePointCacheEntry{},
gcSafepointLastUpdate: time.Now().Add(-4 * time.Second),
gcTTL: 6, // 6 seconds
changeFeeds: changeFeeds,
cfRWriter: s.client,
stoppedFeeds: make(map[model.ChangeFeedID]*model.ChangeFeedStatus),
minGCSafePointCache: minGCSafePointCacheEntry{},
}

time.Sleep(3 * time.Second)
err = mockOwner.flushChangeFeedInfos(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockPDCli.invokeCounter, check.Equals, 1)

err = mockOwner.handleAdminJob(s.ctx)
c.Assert(err, check.IsNil)

time.Sleep(2 * time.Second)
err = mockOwner.flushChangeFeedInfos(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockPDCli.invokeCounter, check.Equals, 2)
err = mockOwner.handleAdminJob(s.ctx)
c.Assert(err, check.IsNil)

c.Assert(mockOwner.stoppedFeeds["test_change_feed_1"], check.NotNil)
c.Assert(mockOwner.stoppedFeeds["test_change_feed_3"], check.NotNil)
c.Assert(mockOwner.changeFeeds["test_change_feed_2"].info.State, check.Equals, model.StateNormal)

time.Sleep(6 * time.Second)
err = mockOwner.flushChangeFeedInfos(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockPDCli.invokeCounter, check.Equals, 2)
c.Assert(mockPDCli.invokeCounter, check.Equals, 3)
err = mockOwner.handleAdminJob(s.ctx)
c.Assert(err, check.IsNil)

time.Sleep(2 * time.Second)
err = mockOwner.flushChangeFeedInfos(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockPDCli.invokeCounter, check.Equals, 4)
err = mockOwner.handleAdminJob(s.ctx)
c.Assert(err, check.IsNil)
c.Assert(mockOwner.stoppedFeeds["test_change_feed_2"], check.NotNil)
Expand Down