table checkpoint-ts can be larger than redo-resolved-ts

[hicqu]

What did you do?

Here is a piece of TiCDC log:

egv-transactions-ch2-ticdc-2 ticdc [2023/09/15 20:04:27.713 +05:30] [INFO] [manager.go:850] ["Start table sink"] [namespace=default] [changefeed=egv-transactions-1-hyd] [tableID=74] [startTs=444278613643624570]
egv-transactions-ch2-ticdc-2 ticdc [2023/09/15 20:04:27.713 +05:30] [INFO] [table_sink_wrapper.go:145] ["Sink is started"] [namespace=default] [changefeed=egv-transactions-1-hyd] [tableID=74] [startTs=444278613643624570] [replicateTs=444278628074651689]
egv-transactions-ch2-ticdc-2 ticdc [2023/09/15 20:04:27.713 +05:30] [INFO] [processor.go:325] ["Add Table finished"] [captureID=18f5d46d-f065-4214-b118-b63dd3dc4fb9] [namespace=default] [changefeed=egv-transactions-1-hyd] [tableID=74] [tableResolvedTs=444278613643624570] [tableCheckpointTs=444278613643624570] [globalCheckpointTs=444278613643624570] [state=Replicating] [isPrepare=false]
egv-transactions-ch2-ticdc-2 ticdc [2023/09/15 20:04:27.813 +05:30] [ERROR] [manager.go:1019] ["sinkManager: resolved ts should not less than checkpoint ts"] [namespace=default] [changefeed=egv-transactions-1-hyd] [tableID=74] [resolvedTs=444278613643624570] [checkpointTs="{\"Mode\":0,\"Ts\":444278627681435676,\"BatchID\":18446744073709551615}"]

What did you expect to see?

No response

What did you see instead?

For a given table, checkpoint-ts is larger than redo-resolved-ts.
This check happens at cdc/processor/sinkmanager/manager.go:1019.
TiCDC version is v6.5.4.

Versions of the cluster

Upstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):

(paste TiDB cluster version here)

Upstream TiKV version (execute tikv-server --version):

(paste TiKV version here)

TiCDC version (execute cdc version):

(paste TiCDC version here)

[nongfushanquan]

/assign @CharlesCheung96

[hicqu]

It's reproduced. Seems lots of tables (more than 200) and more than one captures are also required.

[2023/09/20 13:33:44.178 +08:00] [ERROR] [processor.go:646] ["run processor failed"] [capture=668dd527-ebd6-4f63-b2d9-313966635325] [namespace=default] [changefeed=x] [erro
r="[CDC:ErrInvalidCheckpointTs]checkpointTs(444383368798535681) should not larger than resolvedTs(444383368052736000)"] [errorVerbose="[CDC:ErrInvalidCheckpointTs]checkpoin
tTs(444383368798535681) should not larger than resolvedTs(444383368052736000)\ngithub.com/pingcap/errors.AddStack\n\tgithub.com/pingcap/errors@v0.11.5-0.20220729040631-518f
63d66278/errors.go:174\ngithub.com/pingcap/errors.(*Error).GenWithStackByArgs\n\tgithub.com/pingcap/errors@v0.11.5-0.20220729040631-518f63d66278/normalize.go:164\ngithub.co
m/pingcap/tiflow/cdc/scheduler/internal/v3/agent.(*agent).handleMessageHeartbeat\n\tgithub.com/pingcap/tiflow/cdc/scheduler/internal/v3/agent/agent.go:266\ngithub.com/pingc
ap/tiflow/cdc/scheduler/internal/v3/agent.(*agent).handleMessage\n\tgithub.com/pingcap/tiflow/cdc/scheduler/internal/v3/agent/agent.go:234\ngithub.com/pingcap/tiflow/cdc/sc
heduler/internal/v3/agent.(*agent).Tick\n\tgithub.com/pingcap/tiflow/cdc/scheduler/internal/v3/agent/agent.go:186\ngithub.com/pingcap/tiflow/cdc/processor.(*processor).tick
\n\tgithub.com/pingcap/tiflow/cdc/processor/processor.go:698\ngithub.com/pingcap/tiflow/cdc/processor.(*processor).Tick\n\tgithub.com/pingcap/tiflow/cdc/processor/processor
.go:592\ngithub.com/pingcap/tiflow/cdc/processor.(*managerImpl).Tick\n\tgithub.com/pingcap/tiflow/cdc/processor/manager.go:133\ngithub.com/pingcap/tiflow/pkg/orchestrator.(
*EtcdWorker).Run\n\tgithub.com/pingcap/tiflow/pkg/orchestrator/etcd_worker.go:290\ngithub.com/pingcap/tiflow/cdc/capture.(*captureImpl).runEtcdWorker\n\tgithub.com/pingcap/
tiflow/cdc/capture/capture.go:548\ngithub.com/pingcap/tiflow/cdc/capture.(*captureImpl).run.func4\n\tgithub.com/pingcap/tiflow/cdc/capture/capture.go:380\ngolang.org/x/sync
/errgroup.(*Group).Go.func1\n\tgolang.org/x/sync@v0.1.0/errgroup/errgroup.go:75\nruntime.goexit\n\truntime/asm_amd64.s:1650"]
[2023/09/20 13:33:53.891 +08:00] [ERROR] [feed_state_manager.go:452] ["processor reports an error"] [namespace=default] [changefeed=x] [captureID=668dd527-ebd6-4f63-b2d9-31
3966635325] [error="{\"time\":\"2023-09-20T13:33:53.889723519+08:00\",\"addr\":\"10.2.7.2:8300\",\"code\":\"CDC:ErrInvalidCheckpointTs\",\"message\":\"[CDC:ErrInvalidCheckp
ointTs]checkpointTs(444383368798535681) should not larger than resolvedTs(444383368052736000)\"}"]

[hicqu]

#9772 is tested manually, it can resolve the problem.

[hicqu]

This is caused by function cdc/scheduler/internal/v3/replication.Manager.AdvanceCheckpoint, which advances BarrierTs faster than RedoResolvedTs. After BarrierTs has been advanced to a position, CheckpointTs can be advanced to that position, too. So finally, the check about CheckpointTs must be less than RedoResolvedTs may fails unexpectly.

If consistent.level is set to none, this problem won't happen because RedoResolvedTs won't be used to calculate BarrierTs.

This problem won't cause data lose. It's introduced in #9178, which means it only affects v6.5.4.

[seiya-annie]

/found community