Context deadline exceeded when replicating data without split big txn

[Rustin170506]

What did you do?

1. create tidb and ticdc cluster
2. create changefeed tiup cdc:nightly cli changefeed create --sink-uri="mysql://root@xxx4000/?transaction-atomicity=table" -c "test" --config=changefeed.toml --server xxxxx:8300 and disable split big TXN
3. execute a big txn

workload -database-host 10.2.6.253 -database-db-name test -row-count 5000000 -table-count 3 -tps 50000

mysql -h xxxx -u root -P 4000 -p
use test;
show tables;
begin;
update sbtest0 set k = k + 1;
update sbtest1 set k = k + 1;
update sbtest2 set k = k + 1;
commit;

What did you expect to see?

Changefeed replicates normally.

What did you see instead?

Got an error: context deadline exceeded

Versions of the cluster

master

[nongfushanquan]

/label affects-6.1