Failed to Create CDC Task

This topic has been translated from a Chinese forum by GPT and might contain errors.

Original topic: 创建cdc任务失败

| username: TiDBer_nrpaXrZw

When creating a CDC task in TiDB (TiDB to TiDB), an error occurs indicating that it cannot connect.

Upon testing connectivity, it was found that using the MySQL command to connect succeeds only about once in ten attempts, but telnet connects every time.

Then, testing network latency showed that the latency is stable at 20 milliseconds.

Will such latency prevent the creation of a CDC task?

| username: tidb菜鸟一只 | Original post link

How can we use your database if it takes ten attempts to connect to MySQL successfully?

| username: TiDBer_nrpaXrZw | Original post link

Normally, I can connect locally, but there is a delay between these two servers.
That is, A connecting to B is very laggy, but connecting to B from my local machine has no issues at all.

| username: tidb菜鸟一只 | Original post link

Then you can consider it successfully created, but the task is likely to experience significant delays. CDC network data transmission is a major issue.

| username: zhanggame1 | Original post link

If there is a network problem, solve the network problem. Try pinging with large packets to see if there is any packet loss.

| username: ShawnYan | Original post link

You are connecting across subnets, and the stability is not good. It’s unclear how many layers it has gone through.

By the way, there are so many IP addresses in the photo, and they are not censored. Is that really okay?

| username: redgame | Original post link

1 out of 10 times it succeeds, it seems like it can be created successfully, but later on… Haha, it’s hard to say how it will run…

| username: tony5413 | Original post link

Check the status of the server and TiDB.

| username: 像风一样的男子 | Original post link

If the network issues are not resolved, even if the creation is successful, there will be connection timeouts and data loss later on.

| username: cassblanca | Original post link

Network issues need to be resolved by the network administrator.