@Override
    public int hashCode() {
        return Objects.hash(host, port, username);
    }
The connection pool identifier.
Copy from com.ververica:flink-cdc-base:2.3.0.
inlong-sort/sort-flink/cdc-base/src/main/java/org/apache/inlong/sort/cdc/base/relational/connection/ConnectionPoolId.java