我正在尝试在一个erlang应用程序中创建两个webmachine实例。每个实例都在不同的端口上运行,并具有自己的特定配置。在webmachine doc here之后,我在我的supervisor规范(application_sup.erl)中添加了以下过程:
{
webmachine_instance_1,
{ webmachine_mochiweb, start,
[
[
{ ip, "0.0.0.0"},
{ port, 8000},
{ dispatch, [ {["*"], file_resource, []} ] }
]
]
},
permanent,
5000,
worker,
dynamic
},
{
webmachine_instance_2,
{ webmachine_mochiweb, start,
[
[
{ ip, "0.0.0.0"},
{ port, 8080},
{ dispatch, [ {["*"], file_resource, []} ] }
]
]
},
permanent,
5000,
worker,
dynamic
}
当我包含两个实例时,我收到启动错误,无法启动我的erlang应用程序。在尝试使用单个webmachine实例(webmachine_instance_1或webmachine_instance_2)运行应用程序后,我的应用程序启动正常。
以下是具体错误:
=PROGRESS REPORT==== 11-Mar-2014::17:00:31 ===
supervisor: {local, application_sup}
started: [{pid,<0.230.0>},
{name,webmachine_instance_1},
{mfargs,
{webmachine_mochiweb,start,
[[{ip,"0.0.0.0"},
{port,8000},
{dispatch, [{['*'],
file_resource,
[]
}]}]
]
}
},
{restart_type,permanent},
{shutdown,5000},
{child_type,worker}]
=SUPERVISOR REPORT==== 11-Mar-2014::17:00:31 ===
Supervisor: {local, application_sup}
Context: start_error
Reason: {'EXIT',
{undef,
[{webmachine_mochiweb,start,
[{ip,"0.0.0.0"},
{port,8080},
{dispatch,[{["*"],file_resource,[]}]}],
[]},
{supervisor,do_start_child,2,
[{file,"supervisor.erl"},{line,303}]},
{supervisor,start_children,3,
[{file,"supervisor.erl"},{line,287}]},
{supervisor,init_children,2,
[{file,"supervisor.erl"},{line,253}]},
{gen_server,init_it,6,
[{file,"gen_server.erl"},{line,304}]},
{proc_lib,init_p_do_apply,3,
[{file,"proc_lib.erl"},{line,227}]}]}}
Offender: [{pid,undefined},
{name,webmachine_instance_2},
{mfargs,
{webmachine_mochiweb,start,
[{ip,"0.0.0.0"},
{port,8080},
{dispatch,[{["*"],file_resource,[]}]}]}},
{restart_type,permanent},
{shutdown,5000},
{child_type,worker}]
我对erlang相当新,可能不太了解这里的根本问题 - 根据webmachine doc,我们应该能够启动同一个应用程序的两个实例,但在erlang应用程序中使用不同的配置。
感谢您对此问题的任何帮助/讨论!
答案 0 :(得分:0)
您的子进程配置应具有以下格式:
{Name,
{webmachine_mochiweb, start, [WebConfig]},
permanent, 5000, worker, [mochiweb_socket_server]}
其中Name
和WebConfig
必须对您的webmachine实例唯一。 WebConfig
部分应包含name
和dispatch_group
属性。例如:
WebConfig = [{name,instance1},
{dispatch_group,instance1},
{ip, Ip},
{port, Port},
{log_dir, "priv/log"},
{dispatch, Dispatch}],
因此,对于多个实例,您可能会为您的主管规范提供类似的内容:
WebConfig1 = [{name,instance1},
{dispatch_group,instance1},
{ip, Ip},
{port, Port},
{log_dir, "priv/log"},
{dispatch, Dispatch}],
WebConfig2 = [{name,instance2},
{dispatch_group,instance2},
{ip, Ip},
{port, Port+1},
{log_dir, "priv/log"},
{dispatch, Dispatch}],
Web1 = {instance1,
{webmachine_mochiweb, start, [WebConfig1]},
permanent, 5000, worker, [mochiweb_socket_server]},
Web2 = {instance2,
{webmachine_mochiweb, start, [WebConfig2]},
permanent, 5000, worker, [mochiweb_socket_server]},
Processes = [Web1, Web2],
{ok, { {one_for_one, 10, 10}, Processes} }.
另一件事:从问题中出现的名称application_sup
判断,您可能已经运行了webmachine ./scripts/new_webmachine.sh
并将应用程序名称指定为application
。如果是这样,请不要这样做,因为application
是密钥Erlang OTP模块的名称,并且您的代码将与其发生冲突并导致各种问题。