UPDATE2 我找到了解决方案(感谢 rvirding)。我必须像这样放置对象
Object = riakc_obj:new(list_to_binary(Bucket),
list_to_binary(Time),
list_to_binary(TimeValue)),
ok = riakc_pb_socket:put(Db_pid, Object);
并提出这样的要求
Query = [{map, %query type
{modfun, riak_kv_mapreduce, map_object_value}, %function from riak erlang built-in module
none, true}],
Inputs = {Bucket, [[<<"between">>, <<"0">>, <<"0.05">>]]},
Result = riakc_pb_socket:mapred(Pid, Inputs, Query),
我认为应该在文档中提到它。
顺便提一句!如果我写
Object = riakc_obj:new(<<Bucket>>,
<<Time>>,
<<TimeValue>>),
我收到关于 badarg 的错误消息。仍然对此感到困惑。(
更新
如果我写这个
Inputs = {Bucket, [[<<"between">>, 0, 1]]}
我没有收到任何错误,我什至得到了“ok”的结果,但它是空的,这不是预期的行为。)
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我完全失去了理智,但我必须完成它。
我有一个简单的应用程序:它从 txt 文件中提取数据(数据,如“时间戳值”),将其推送到 Riak 并进行一些范围查询。问题是当我进行密钥过滤器查询时,我得到 {error,disconnected}。我以这种方式在 riak 中存储数据:key - 时间戳(如 0.43),value - value(如 1.14),bucket - 添加数据的时间(如“2011-07-24-23-39-45”)。这是请求的代码:
(dca_db.erl)
handle_call({range_query, Bucket, From, To}, _, #state{db_pid = Pid} = State) ->
Query = [{map, %query type
{modfun, riak_kv_mapreduce, map_object_value}, %function from riak erlang built-in module
none, true}],
Inputs = {Bucket, [["between", 0, 1]]},
Result = riakc_pb_socket:mapred(Pid, Inputs, Query),
{reply, Result, State};
(测试/dca_db_tests.erl)
range_request(Pid) ->
Bucket = <<"2011-07-24-23-39-45">>,
Result = gen_server:call(Pid, {range_query, Bucket, 0, 1}),
error_logger:info_msg("RESULT:~p~n",[Result]).
你可以在 github 中找到我的代码 – https://github.com/DimitryDushkin/distributed_calc_riak_matlab
如果我使用类似(在 dca_db.erl 中)
Inputs = {Bucket, [["eq", 1]]},
我有另一个错误
Compiled src/dca_db.erl
undefined
*unexpected termination of test process*
::{{badmatch,{<<"2011-07-24-23-39-45">>,[["eq",1]]}},
[{dca_db,handle_call,3},
{gen_server,handle_msg,5},
{proc_lib,init_p_do_apply,3}]}
=ERROR REPORT==== 25-Jul-2011::00:27:24 ===
** Generic server dca_db terminating
** Last message in was {range_query,<<"2011-07-24-23-39-45">>,0,1}
** When Server state == {state,<0.105.0>}
** Reason for termination ==
** {{badmatch,{<<"2011-07-24-23-39-45">>,[["eq",1]]}},
[{dca_db,handle_call,3},
{gen_server,handle_msg,5},
{proc_lib,init_p_do_apply,3}]}
=======================================================
Failed: 0. Skipped: 0. Passed: 1.
One or more tests were cancelled.
Cover analysis: /Users/ddushkin/Documents/workspaces/eclipse/distributed_calc_riak_matlab/.eunit/index.html
ERROR: One or more eunit tests failed.
make: *** [test_db] Error 1
如果我不使用过滤器,一切正常:
Inputs = Bucket,
谢谢你。