Downstream TiDB Cluster Pulling CDC from Upstream TiDB Cluster

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

Original topic: 下游tidb集群拉取上游tidb集群 cdc

| username: juecong

[TiDB Usage Environment] Production Environment
[TiDB Version]
Upstream Cluster 6.1.0 Downstream Cluster 7.1.1
[Encountered Problem: Problem Phenomenon and Impact]
Two sets of TiDB clusters are deployed on different cloud providers (A, B). Now, it is necessary to migrate the data from the TiDB cluster of A to the TiDB cluster of B through the public network. Full migration is fine, but when using CDC for incremental migration, the CDC is created in the downstream TiDB cluster B, intending to pull the incremental data from A to B to reduce the pressure on the TiDB cluster A. However, it reports an error that the PD cannot find the leader.
[Attachment: Screenshot/Log/Monitoring]

| username: nongfushanquan | Original post link

Is the downstream and upstream network connected? TiCDC needs to be connected to both upstream TiKV/PD. In your case, it is recommended to deploy TiCDC upstream.

| username: tidb菜鸟一只 | Original post link

Can the downstream directly access the upstream’s PD? Try using curl to check.

| username: juecong | Original post link

The downstream can directly access the upstream PD, and the ports are open. Telnet works.

| username: juecong | Original post link

Because the full database increment will affect the upstream business, the CDC is placed in the downstream CDC. Are you referring to opening the external network port of the upstream TiKV as well? The upstream PD is accessible, and telnet works.

| username: juecong | Original post link

Then I saw the error message indicating that the leader could not be found, so I directly connected to PD using the public IP address of the leader’s machine, and then another error occurred.

| username: tidb菜鸟一只 | Original post link

Execute this command downstream:
curl http://{pdAddr}/pd/api/v1/cluster/status
See if there is any response?

| username: 舞动梦灵 | Original post link

Has this issue been resolved? Is the TiCDC real-time synchronization version the same? Does it have anything to do with the version?

| username: redgame | Original post link

It doesn’t work according to the screenshot.