一般说来抓dump 4种 方式：
1. erlang:halt(“abort”).
2. 在erlang shell下输入CTRL C + “大写的A”
3.等着进程崩溃自己产生dump
4.kill -SIGUSR1 <pid> （shell 无法进入时可以使用）
不过4个方式无一不是需要node crash掉，如果我只想sapshot 一份进程状态以便分析呢？
在google groups 找到答案，现在链接找不到了，分享一下：
crash_dump() ->
Date = erlang:list_to_binary(rfc1123_local_date()),
Header = binary:list_to_bin([<<"=erl_crash_dump:0.2\n">>,Date,<<"\nSystem version: ">>]),
Ets = ets_info(),
Report = binary:list_to_bin([Header,erlang:list_to_binary(erlang:system_info(system_version)),
erlang:system_info(info),erlang:system_info(procs),Ets,erlang:system_info(dist),
<<"=loaded_modules\n">>,binary:replace(erlang:system_info(loaded),
<<"\n">>,<<"\n=mod:">>,[global])]),
file:write_file("erl_crash.dump",Report). ets_info() ->
binary:list_to_bin([ets_table_info(T)||T<-ets:all()]). ets_table_info(Table) ->
Info = ets:info(Table),
Owner = erlang:list_to_binary(erlang:pid_to_list(proplists:get_value(owner,Info))),
TableN = erlang:list_to_binary(erlang:atom_to_list(proplists:get_value(name,Info))),
Name = erlang:list_to_binary(erlang:atom_to_list(proplists:get_value(name,Info))),
Objects = erlang:list_to_binary(erlang:integer_to_list(proplists:get_value(size,Info))),
binary:list_to_bin([<<"=ets:">>,Owner,<<"\nTable: ">>,TableN,<<"\nName: ">>,Name,
<<"\nObjects: ">>,Objects,<<"\n">>]). rfc1123_local_date() ->
rfc1123_local_date(os:timestamp()).
rfc1123_local_date({A,B,C}) ->
rfc1123_local_date(calendar:now_to_local_time({A,B,C}));
rfc1123_local_date({{YYYY,MM,DD},{Hour,Min,Sec}}) ->
DayNumber = calendar:day_of_the_week({YYYY,MM,DD}),
lists:flatten(
io_lib:format("~s, ~2.2.0w ~3.s ~4.4.0w ~2.2.0w:~2.2.0w:~2.2.0w GMT",
[httpd_util:day(DayNumber),DD,httpd_util:month(MM),YYYY,Hour,Min,Sec]));
rfc1123_local_date(Epoch) when erlang:is_integer(Epoch) ->
rfc1123_local_date(calendar:gregorian_seconds_to_datetime(Epoch+62167219200)).
erlang 的crash dump 是一个进程详细信息快照的文本文件，此方式自己拼接一个类似的文件，嗯crash_dumpviewer 会有警告，不过还是很好用。