TiCDC owner gets stuck when creating new kafka producer #3352

amyangfei · 2021-11-09T10:54:53Z

What did you do?

Setup a ticdc cluster, replicating data to Kafka
Sending pause changefeed or remove changefeed doesn't work

What did you expect to see?

No response

What did you see instead?

owner gets stuck

ticdc goroutins:

goroutines_222.log
goroutines_222_second.log

ticdc log:

cdc.log

metrics:
metrics.tar.gz

Two owner newChangeFeed, looks like some dead lock.

goroutine 1300 [semacquire]:
sync.runtime_SemacquireMutex(0xc00957a3d4, 0x0, 0x1)
	runtime/sema.go:71 +0x47
sync.(*Mutex).lockSlow(0xc00957a3d0)
	sync/mutex.go:138 +0xfc
sync.(*Mutex).Lock(...)
	sync/mutex.go:81
github.com/Shopify/sarama.(*Broker).send(0xc00957a380, 0x32d75c0, 0xc005f18bd0, 0xc301, 0x0, 0x0, 0x0)
	github.com/Shopify/[email protected]/broker.go:716 +0x6e2
github.com/Shopify/sarama.(*Broker).sendAndReceive(0xc00957a380, 0x32d75c0, 0xc005f18bd0, 0x32d7620, 0xc0058157c0, 0x2942400, 0x1)
	github.com/Shopify/[email protected]/broker.go:765 +0x84
github.com/Shopify/sarama.(*Broker).GetMetadata(0xc00957a380, 0xc005f18bd0, 0x0, 0x0, 0x1)
	github.com/Shopify/[email protected]/broker.go:283 +0x70
github.com/Shopify/sarama.(*client).tryRefreshMetadata(0xc0093b42d0, 0x0, 0x0, 0x0, 0x64, 0x0, 0x0, 0x0, 0x22cd430, 0x0)
	github.com/Shopify/[email protected]/client.go:880 +0x4d1
github.com/Shopify/sarama.(*client).tryRefreshMetadata.func2(0x3249ba0, 0xc000c5c3b0, 0x1, 0x1)
	github.com/Shopify/[email protected]/client.go:859 +0x1d5
github.com/Shopify/sarama.(*client).tryRefreshMetadata(0xc0093b42d0, 0x0, 0x0, 0x0, 0x65, 0x0, 0x0, 0x0, 0x22cd430, 0x0)
	github.com/Shopify/[email protected]/client.go:927 +0xc51
....
github.com/Shopify/sarama.(*client).tryRefreshMetadata(0xc0093b42d0, 0x0, 0x0, 0x0, 0x77, 0x0, 0x0, 0x0, 0x22cd430, 0x0)
	github.com/Shopify/[email protected]/client.go:927 +0xc51
github.com/Shopify/sarama.(*client).tryRefreshMetadata.func2(0x3249ba0, 0xc000c5c3b0, 0x1, 0x1)
	github.com/Shopify/[email protected]/client.go:859 +0x1d5
github.com/Shopify/sarama.(*client).tryRefreshMetadata(0xc0093b42d0, 0x0, 0x0, 0x0, 0x78, 0x0, 0x0, 0x0, 0x0, 0x0)
	github.com/Shopify/[email protected]/client.go:927 +0xc51
github.com/Shopify/sarama.(*client).RefreshMetadata(0xc0093b42d0, 0x0, 0x0, 0x0, 0x7f2b94f9d62c, 0x12)
	github.com/Shopify/[email protected]/client.go:473 +0xbe
github.com/Shopify/sarama.NewClient(0xc0022aa750, 0x3, 0x3, 0xc0092d7c00, 0x2ad5040, 0x2, 0x3, 0xc0022aa750)
	github.com/Shopify/[email protected]/client.go:167 +0x331
github.com/Shopify/sarama.NewAsyncProducer(0xc0022aa750, 0x3, 0x3, 0xc0092d7c00, 0x0, 0x2, 0xc0022aa750, 0x3)
	github.com/Shopify/[email protected]/async_producer.go:126 +0x4d
github.com/pingcap/ticdc/cdc/sink/producer/kafka.NewKafkaSaramaProducer(0x32b7e80, 0xc004b6e7c0, 0xc000242b08, 0x38, 0xc000242b41, 0x15, 0x100000000, 0xc000242b65, 0x5, 0x4000000, ...)
	github.com/pingcap/ticdc@/cdc/sink/producer/kafka/kafka.go:328 +0x35a
github.com/pingcap/ticdc/cdc/sink.newKafkaSaramaSink(0x32b7e80, 0xc004b6e7c0, 0xc004876480, 0xc005165720, 0xc005d31b30, 0xc005d31b00, 0xc0093b0540, 0xc000c6a388, 0x0, 0xc000c6a340)
	github.com/pingcap/ticdc@/cdc/sink/mq.go:475 +0x44b
github.com/pingcap/ticdc/cdc/sink.init.1.func3(0x32b7e80, 0xc004b6e7c0, 0xc005ff39fa, 0xc, 0xc004876480, 0xc005165720, 0xc005d31b30, 0xc005d31b00, 0xc0093b0540, 0x27fe8e0, ...)
	github.com/pingcap/ticdc@/cdc/sink/sink.go:81 +0x7a
github.com/pingcap/ticdc/cdc/sink.NewSink(0x32b7e80, 0xc004b6e7c0, 0xc005ff39fa, 0xc, 0xc000242b00, 0xae, 0xc005165720, 0xc005d31b30, 0xc005d31b00, 0xc0093b0540, ...)
	github.com/pingcap/ticdc@/cdc/sink/sink.go:113 +0x1ef
github.com/pingcap/ticdc/cdc.(*Owner).newChangeFeed(0xc0039f2140, 0x32b7e80, 0xc004b6e7c0, 0xc005ff39fa, 0xc, 0xc005585bc0, 0xc005d31ad0, 0xc00463a300, 0x5f4063fe7d00000, 0x0, ...)
	github.com/pingcap/ticdc@/cdc/owner.go:414 +0x21bb
github.com/pingcap/ticdc/cdc.(*Owner).loadChangeFeeds(0xc0039f2140, 0x32b7e80, 0xc0054b6800, 0x0, 0x0)
	github.com/pingcap/ticdc@/cdc/owner.go:615 +0xe1c
github.com/pingcap/ticdc/cdc.(*Owner).run(0xc0039f2140, 0x32b7e80, 0xc0054b6800, 0x0, 0x0)
	github.com/pingcap/ticdc@/cdc/owner.go:1309 +0xe8
github.com/pingcap/ticdc/cdc.(*Owner).Run(0xc0039f2140, 0x32b7e80, 0xc0056960c0, 0x1dcd6500, 0x0, 0x0)
	github.com/pingcap/ticdc@/cdc/owner.go:1204 +0x3af
github.com/pingcap/ticdc/cdc.(*Server).campaignOwnerLoop(0xc000c8e660, 0x32b7e80, 0xc0056960c0, 0xc004936e40, 0x16b5000000000008)
	github.com/pingcap/ticdc@/cdc/server.go:172 +0x540
github.com/pingcap/ticdc/cdc.(*Server).run.func1(0xc000500f68, 0xc004d08240)
	github.com/pingcap/ticdc@/cdc/server.go:255 +0x3c
golang.org/x/sync/errgroup.(*Group).Go.func1(0xc005435d40, 0xc002f0c500)
	golang.org/x/[email protected]/errgroup/errgroup.go:57 +0x64
created by golang.org/x/sync/errgroup.(*Group).Go
	golang.org/x/[email protected]/errgroup/errgroup.go:54 +0x66

goroutine 227 [semacquire]:
sync.runtime_SemacquireMutex(0xc003de2054, 0x0, 0x1)
	runtime/sema.go:71 +0x47
sync.(*Mutex).lockSlow(0xc003de2050)
	sync/mutex.go:138 +0xfc
sync.(*Mutex).Lock(...)
	sync/mutex.go:81
github.com/Shopify/sarama.(*Broker).send(0xc003de2000, 0x32d75c0, 0xc0043b9080, 0xc301, 0x0, 0x0, 0x0)
	github.com/Shopify/[email protected]/broker.go:716 +0x6e2
github.com/Shopify/sarama.(*Broker).sendAndReceive(0xc003de2000, 0x32d75c0, 0xc0043b9080, 0x32d7620, 0xc0045f7590, 0x2942400, 0x1)
	github.com/Shopify/[email protected]/broker.go:765 +0x84
github.com/Shopify/sarama.(*Broker).GetMetadata(0xc003de2000, 0xc0043b9080, 0x0, 0x0, 0x1)
	github.com/Shopify/[email protected]/broker.go:283 +0x70
github.com/Shopify/sarama.(*client).tryRefreshMetadata(0xc002e81b00, 0x0, 0x0, 0x0, 0x5f, 0x0, 0x0, 0x0, 0x22cd430, 0x0)
	github.com/Shopify/[email protected]/client.go:880 +0x4d1
...
github.com/Shopify/sarama.(*client).RefreshMetadata(0xc002e81b00, 0x0, 0x0, 0x0, 0x7f2b94f9d02c, 0x12)
	github.com/Shopify/[email protected]/client.go:473 +0xbe
github.com/Shopify/sarama.NewClient(0xc00387ebd0, 0x3, 0x3, 0xc003007880, 0x2ad5040, 0x2, 0x3, 0xc00387ebd0)
	github.com/Shopify/[email protected]/client.go:167 +0x331
github.com/Shopify/sarama.NewAsyncProducer(0xc00387ebd0, 0x3, 0x3, 0xc003007880, 0x0, 0x2, 0xc00387ebd0, 0x3)
	github.com/Shopify/[email protected]/async_producer.go:126 +0x4d
github.com/pingcap/ticdc/cdc/sink/producer/kafka.NewKafkaSaramaProducer(0x32b7e80, 0xc000e7ebc0, 0xc000242638, 0x38, 0xc000242671, 0x15, 0x100000000, 0xc000242695, 0x5, 0x4000000, ...)
	github.com/pingcap/ticdc@/cdc/sink/producer/kafka/kafka.go:328 +0x35a
github.com/pingcap/ticdc/cdc/sink.newKafkaSaramaSink(0x32b7e80, 0xc000e7ebc0, 0xc0013fcc00, 0xc000818be0, 0xc000c550e0, 0xc000c54e10, 0xc003883bc0, 0xc000c6a388, 0x0, 0xc000c6a340)
	github.com/pingcap/ticdc@/cdc/sink/mq.go:475 +0x44b
github.com/pingcap/ticdc/cdc/sink.init.1.func3(0x32b7e80, 0xc000e7ebc0, 0xc00016e8ba, 0xc, 0xc0013fcc00, 0xc000818be0, 0xc000c550e0, 0xc000c54e10, 0xc003883bc0, 0x27fe8e0, ...)
	github.com/pingcap/ticdc@/cdc/sink/sink.go:81 +0x7a
github.com/pingcap/ticdc/cdc/sink.NewSink(0x32b7e80, 0xc000e7ebc0, 0xc00016e8ba, 0xc, 0xc000242630, 0xae, 0xc000818be0, 0xc000c550e0, 0xc000c54e10, 0xc003883bc0, ...)
	github.com/pingcap/ticdc@/cdc/sink/sink.go:113 +0x1ef
github.com/pingcap/ticdc/cdc.(*Owner).newChangeFeed(0xc0006783c0, 0x32b7e80, 0xc000e7ebc0, 0xc00016e8ba, 0xc, 0xc0008790b0, 0xc000879860, 0xc0012d6180, 0x5f4063fe7d00000, 0x0, ...)
	github.com/pingcap/ticdc@/cdc/owner.go:414 +0x21bb
github.com/pingcap/ticdc/cdc.(*Owner).loadChangeFeeds(0xc0006783c0, 0x32b7f40, 0xc000d9d7a0, 0x0, 0x0)
	github.com/pingcap/ticdc@/cdc/owner.go:615 +0xe1c
github.com/pingcap/ticdc/cdc.(*Owner).watchCapture(0xc0006783c0, 0x32b7e80, 0xc0004087c0, 0x1, 0x0)
	github.com/pingcap/ticdc@/cdc/owner.go:1497 +0xdc
github.com/pingcap/ticdc/cdc.(*Owner).startCaptureWatcher.func1(0x32b7e80, 0xc0004087c0, 0xc0006783c0)
	github.com/pingcap/ticdc@/cdc/owner.go:1609 +0xd2
created by github.com/pingcap/ticdc/cdc.(*Owner).startCaptureWatcher
	github.com/pingcap/ticdc@/cdc/owner.go:1598 +0x7d

Versions of the cluster

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

(paste TiDB cluster version here)

TiCDC version (execute cdc version):

v5.0.1

The text was updated successfully, but these errors were encountered:

liuzix · 2021-11-09T13:38:17Z

The root cause is that the initialization of a sarama.(*Broker) blocks the owner goroutine from doing everything else.

This does not seem to be a deadlock problem, as the only other goroutine potentially holding the Mutex is waiting on network.
The theoretical maximum duration for the owner to be blocked still needs investigation. It is related to the settings of sarama. We should also check for known issues of sarama in case there is an unexpected behavior.
The problem should affect the new owner as well. The owner would be blocked here https://github.com/pingcap/ticdc/blob/b4c6b17ca6cda6ba04d6b1d1a49e9aa08c1d4d16/cdc/owner/async_sink.go#L80

goroutine 11818 [IO wait]:
internal/poll.runtime_pollWait(0x7f2b92a2df50, 0x77, 0xc003caf500)
	runtime/netpoll.go:184 +0x55
internal/poll.(*pollDesc).wait(0xc000ff5518, 0x77, 0x32b7f00, 0xc0091e1f80, 0xc000ff5500)
	internal/poll/fd_poll_runtime.go:87 +0x45
internal/poll.(*pollDesc).waitWrite(...)
	internal/poll/fd_poll_runtime.go:96
internal/poll.(*FD).WaitWrite(...)
	internal/poll/fd_unix.go:498
net.(*netFD).connect(0xc000ff5500, 0x32b7f00, 0xc0091e1f80, 0x0, 0x0, 0x324d2a0, 0xc004856ac0, 0x0, 0x0, 0x0, ...)
	net/fd_unix.go:152 +0x29d
net.(*netFD).dial(0xc000ff5500, 0x32b7f00, 0xc0091e1f80, 0x32dcba0, 0x0, 0x32dcba0, 0xc005f18c30, 0x0, 0x1, 0xc0055af858)
	net/sock_posix.go:149 +0xff
net.socket(0x32b7f00, 0xc0091e1f80, 0x2c1593d, 0x3, 0x2, 0x1, 0x0, 0x0, 0x32dcba0, 0x0, ...)
	net/sock_posix.go:70 +0x1c0
net.internetSocket(0x32b7f00, 0xc0091e1f80, 0x2c1593d, 0x3, 0x32dcba0, 0x0, 0x32dcba0, 0xc005f18c30, 0x1, 0x0, ...)
	net/ipsock_posix.go:141 +0x141
net.(*sysDialer).doDialTCP(0xc000ff5480, 0x32b7f00, 0xc0091e1f80, 0x0, 0xc005f18c30, 0x27c9020, 0x50f1538, 0x0)
	net/tcpsock_posix.go:65 +0xc2
net.(*sysDialer).dialTCP(0xc000ff5480, 0x32b7f00, 0xc0091e1f80, 0x0, 0xc005f18c30, 0xc002a4d5a0, 0x10, 0x10)
	net/tcpsock_posix.go:61 +0xd7
net.(*sysDialer).dialSingle(0xc000ff5480, 0x32b7f00, 0xc0091e1f80, 0x327d680, 0xc005f18c30, 0x0, 0x0, 0x0, 0x0)
	net/dial.go:578 +0x36e
net.(*sysDialer).dialSerial(0xc000ff5480, 0x32b7f00, 0xc0091e1f80, 0xc002a4d5a0, 0x1, 0x1, 0x0, 0x0, 0x0, 0x0)
	net/dial.go:546 +0x221
net.(*Dialer).DialContext(0xc0091e15c0, 0x32b7ec0, 0xc0000e8000, 0x2c1593d, 0x3, 0xc000242b2e, 0x12, 0x0, 0x0, 0x0, ...)
	net/dial.go:424 +0x666
net.(*Dialer).Dial(0xc0091e15c0, 0x2c1593d, 0x3, 0xc000242b2e, 0x12, 0xc003f04ec0, 0x4052da, 0xc0012fcf00, 0xc0012d5020)
	net/dial.go:347 +0x75
github.com/Shopify/sarama.(*Broker).Open.func1()
	github.com/Shopify/[email protected]/broker.go:158 +0xe2
github.com/Shopify/sarama.withRecover(0xc006269680)
	github.com/Shopify/[email protected]/utils.go:43 +0x4d
created by github.com/Shopify/sarama.(*Broker).Open
	github.com/Shopify/[email protected]/broker.go:154 +0x120

TODO

Add a mechanism to create sinks asynchronously, which will print warnings in case of timeouts (note that creating a sarama client does not seem to be cancellable by a context).
Investigate the semantics of sarama timeouts, and test whether it behaves as expected
Find a way to gracefully cancel the producer if the user wants to remove (or pause) the changefeed but the producer is still initializing.

amyangfei · 2021-11-09T17:39:07Z

This issue doesn't block v5.3.0 release.

amyangfei added type/bug The issue is confirmed as a bug. area/ticdc Issues or PRs related to TiCDC. labels Nov 9, 2021

amyangfei mentioned this issue Nov 9, 2021

Tracking issue related to Kafka sink #2971

Open

19 tasks

liuzix self-assigned this Nov 9, 2021

overvenus added the severity/major label Nov 9, 2021

amyangfei mentioned this issue Nov 9, 2021

TiCDC owner availability check #3354

Open

amyangfei added severity/critical and removed severity/major labels Nov 9, 2021

3AceShowHand mentioned this issue Nov 19, 2021

Verify kafka producer configuration works in a reasonable way. #3538

Closed

amyangfei mentioned this issue Nov 23, 2021

TiCDC changefeed sequential initialization #3588

Closed

Rustin170506 mentioned this issue Nov 30, 2021

sink(ticdc): Set config.Metadata.Timeout correctly #3665

Merged

3AceShowHand mentioned this issue Dec 6, 2021

owner(ticdc): asynchronously create sink #3598

Merged

overvenus assigned 3AceShowHand and unassigned liuzix Dec 7, 2021

ti-chi-bot closed this as completed in #3598 Dec 16, 2021

overvenus mentioned this issue Jan 13, 2022

releases: add TiDB 5.4.0 release notes pingcap/docs-cn#8061

Merged

14 tasks

maxshuang mentioned this issue Jan 13, 2022

How to trace the problem that cause TiCDC slow latency #4264

Closed

4 tasks

jebter added affects-5.0 affects-4.0 labels Apr 10, 2022

ti-chi-bot added affects-5.2 affects-5.1 label-for-test and removed label-for-test labels Jun 9, 2023

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TiCDC owner gets stuck when creating new kafka producer #3352

TiCDC owner gets stuck when creating new kafka producer #3352

amyangfei commented Nov 9, 2021 •

edited

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liuzix commented Nov 9, 2021 •

edited by 3AceShowHand

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amyangfei commented Nov 9, 2021

TiCDC owner gets stuck when creating new kafka producer #3352

TiCDC owner gets stuck when creating new kafka producer #3352

Comments

amyangfei commented Nov 9, 2021 • edited Loading

What did you do?

What did you expect to see?

What did you see instead?

Versions of the cluster

liuzix commented Nov 9, 2021 • edited by 3AceShowHand Loading

amyangfei commented Nov 9, 2021

amyangfei commented Nov 9, 2021 •

edited

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liuzix commented Nov 9, 2021 •

edited by 3AceShowHand

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