TiCDC should use TiDB gcTuner in a more reasonable way.

[asddongmen]

What did you do?

Start a cdc server in a container that has 64GB memory.

What did you expect to see?

The CDC server can accurately detect the system memory, which is 64GB.

What did you see instead?

I sopt a log like this:

[2023/09/08 22:56:49.068 +08:00] [INFO] [server.go:229] ["enable gctuner, set memory limit"] [bytes=184467440737092648] [memory="164 PiB"]

Versions of the cluster

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

(paste TiDB cluster version here)

Upstream TiKV version (execute tikv-server --version):

(paste TiKV version here)

TiCDC version (execute cdc version):

(paste TiCDC version here)

[nongfushanquan]

/assign @sdojjy