json codec met panic: interface conversion: interface {} is string, not []uint8

[amyangfei]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. What did you do? If possible, provide a recipe for reproducing the error.

panic: interface conversion: interface {} is string, not []uint8

goroutine 3552 [running]:
github.com/pingcap/ticdc/cdc/sink/codec.(*column).FromSinkColumn(0xc00e3c7b88, 0xc01f526e40)
	github.com/pingcap/ticdc/cdc/sink/codec/json.go:67 +0x357
github.com/pingcap/ticdc/cdc/sink/codec.sinkColumns2JsonColumns(0xc016bfda20, 0x16, 0x16, 0xc031903bc0)
	github.com/pingcap/ticdc/cdc/sink/codec/json.go:227 +0xaa
github.com/pingcap/ticdc/cdc/sink/codec.rowEventToMqMessage(0xc01f511000, 0xc00dd2a8c0, 0x4a4a368)
	github.com/pingcap/ticdc/cdc/sink/codec/json.go:215 +0x16e
github.com/pingcap/ticdc/cdc/sink/codec.(*JSONEventBatchEncoder).AppendRowChangedEvent(0xc00dd2a8c0, 0xc01f511000, 0x3, 0x2, 0x1)
	github.com/pingcap/ticdc/cdc/sink/codec/json.go:372 +0x43
github.com/pingcap/ticdc/cdc/sink.(*mqSink).runWorker(0xc00e72aea0, 0x2e57ba0, 0xc00e7b0940, 0x0, 0x0, 0x0)
	github.com/pingcap/ticdc/cdc/sink/mq.go:349 +0x3c0
github.com/pingcap/ticdc/cdc/sink.(*mqSink).run.func1(0x0, 0x0)
	github.com/pingcap/ticdc/cdc/sink/mq.go:279 +0x46
golang.org/x/sync/errgroup.(*Group).Go.func1(0xc00d90fda0, 0xc00595ea40)
	golang.org/x/sync@v0.0.0-20201020160332-67f06af15bc9/errgroup/errgroup.go:57 +0x59
created by golang.org/x/sync/errgroup.(*Group).Go
	golang.org/x/sync@v0.0.0-20201020160332-67f06af15bc9/errgroup/errgroup.go:54 +0x66

• resume changefeed can recover

4. Versions of the cluster

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

     v4.0.9
     

   • TiCDC version (execute cdc version):

     v4.0.12