Where `response_op` is the responseop mentioned above, PipelineServer will initialize Channels according to the topology relationship of each OP and build the calculation graph. `config_yml_path` is the configuration file of PipelineServer. The example file is as follows:
```yaml
port:18080# gRPC port
rpc_port:18080# gRPC port
worker_num:1# gRPC thread pool size (the number of processes in the process version servicer). The default is 1
build_dag_each_worker:false# Whether to use process server or not. The default is false
http_port:0# HTTP service port. Do not start HTTP service when the value is less or equals 0. The default value is 0.
dag:
is_thread_op:true# Whether to use the thread version of OP. The default is true
client_type:brpc# Use brpc or grpc client. The default is brpc