Communicate in process or via gRPC

Starting with Ansys 2022 R2, PyDPF can communicate either via In Process or via gRPC with DPF C++ core server (Ans.Dpf.Grpc.exe). To choose which type of ansys.dpf.core.server_types.BaseServer (object defining the type of communication and the server instance to communicate with) to use, a ansys.dpf.core.server_factory.ServerConfig class should be used. Until Ansys 2022R1, only gRPC communication using python module ansys.grpc.dpf is supported (now called ansys.dpf.core.server_types.LegacyGrpcServer), starting with Ansys 2022 R2, three types of servers are supported:

• ansys.dpf.core.server_types.InProcessServer loading DPF in process. Cannot run on Docker.

• ansys.dpf.core.server_types.GrpcServer using gRPC communication through the DPF gRPC CLayer Ans.Dpf.GrpcClient.

• ansys.dpf.core.server_types.LegacyGrpcServer using gRPC communication through the Python module ansys.grpc.dpf.

To change the default type of server’s configuration used by DPF change:

• the global variable SERVER_CONFIGURATION at the beginning of the python script.

• the environment variable DPF_SERVER_TYPE before running the python executable, see ansys.dpf.core.server_factory.ServerConfig for more information.

import os
from ansys.dpf import core as dpf

Start servers with custom server configuration

in_process_config = dpf.AvailableServerConfigs.InProcessServer
grpc_config = dpf.AvailableServerConfigs.GrpcServer
legacy_grpc_config = dpf.AvailableServerConfigs.LegacyGrpcServer

if "DPF_DOCKER" not in os.environ.keys():
    in_process_server = dpf.start_local_server(config=in_process_config)
grpc_server = dpf.start_local_server(config=grpc_config)
legacy_grpc_server = dpf.start_local_server(config=legacy_grpc_config)

Equivalent to:

in_process_config = dpf.ServerConfig(protocol=None, legacy=False)
grpc_config = dpf.ServerConfig(
    protocol=dpf.server_factory.CommunicationProtocols.gRPC, legacy=False
)
legacy_grpc_config = dpf.ServerConfig(
    protocol=dpf.server_factory.CommunicationProtocols.gRPC, legacy=True
)

if "DPF_DOCKER" not in os.environ.keys():
    in_process_server = dpf.start_local_server(config=in_process_config, as_global=False)
grpc_server = dpf.start_local_server(config=grpc_config, as_global=False)
legacy_grpc_server = dpf.start_local_server(config=legacy_grpc_config, as_global=False)

Create data on different servers

if "DPF_DOCKER" not in os.environ.keys():
    in_process_field = dpf.fields_factory.create_scalar_field(2, server=in_process_server)
    in_process_field.append([1.0], 1)
    in_process_field.append([2.0], 2)
grpc_field = dpf.fields_factory.create_scalar_field(2, server=grpc_server)
grpc_field.append([1.0], 1)
grpc_field.append([2.0], 2)
legacy_grpc_field = dpf.fields_factory.create_scalar_field(2, server=legacy_grpc_server)
legacy_grpc_field.append([1.0], 1)
legacy_grpc_field.append([2.0], 2)

if "DPF_DOCKER" not in os.environ.keys():
    print(in_process_field, type(in_process_field._server), in_process_field._server)
print(grpc_field, type(grpc_field._server), grpc_field._server)
print(legacy_grpc_field, type(legacy_grpc_field._server), legacy_grpc_field._server)

DPF  Field
  Location: Nodal
  Unit:
  2 entities
  Data: 1 components and 2 elementary data

  IDs                   data
  ------------          ----------
  1                     1.000000e+00

  2                     2.000000e+00


 <class 'ansys.dpf.core.server_types.InProcessServer'> DPF Server: {'server_ip': '', 'server_port': None, 'server_process_id': 6964, 'server_version': '7.0', 'os': 'nt'}
DPF  Field
  Location: Nodal
  Unit:
  2 entities
  Data: 1 components and 2 elementary data

  IDs                   data
  ------------          ----------
  1                     1.000000e+00

  2                     2.000000e+00


 <class 'ansys.dpf.core.server_types.GrpcServer'> DPF Server: {'server_ip': '127.0.0.1', 'server_port': 50056, 'server_process_id': 4288, 'server_version': '7.0', 'os': 'nt'}
DPF  Field
  Location: Nodal
  Unit:
  2 entities
  Data: 1 components and 2 elementary data

  IDs                   data
  ------------          ----------
  1                     1.000000e+00

  2                     2.000000e+00


 <class 'ansys.dpf.core.server_types.LegacyGrpcServer'> DPF Server: {'server_ip': '127.0.0.1', 'server_port': 50054, 'server_process_id': 1932, 'server_version': '7.0', 'os': 'nt'}

Choose default configuration

Once a default configuration is chosen, a server of the chosen type is automatically started when a DPF object is created:

initial_config = dpf.SERVER_CONFIGURATION

dpf.SERVER_CONFIGURATION = dpf.AvailableServerConfigs.GrpcServer
grpc_field = dpf.fields_factory.create_scalar_field(2)
grpc_field.append([1.0], 1)
grpc_field.append([2.0], 2)
print(grpc_field, type(grpc_field._server), grpc_field._server)

# Go back to default config:
dpf.SERVER_CONFIGURATION = initial_config

DPF  Field
  Location: Nodal
  Unit:
  2 entities
  Data: 1 components and 2 elementary data

  IDs                   data
  ------------          ----------
  1                     1.000000e+00

  2                     2.000000e+00


 <class 'ansys.dpf.core.server_types.LegacyGrpcServer'> DPF Server: {'server_ip': '127.0.0.1', 'server_port': 50055, 'server_process_id': 2004, 'server_version': '7.0', 'os': 'nt'}