任何人都可以帮我解决这个问题，我有问题的堆栈跟踪，但无法理解跟踪的实际含义。
当我尝试从Riak数据库中的存储桶中检索所有数据时发生错误。我使用java-riak-client库作为ORM。我可以弄清楚它是一个MapReduce问题，但除此之外......
下面是实际的堆栈跟踪，我实际上无法弄清楚它指向的是什么错误， 我试图找出错误显示的记录。 @Update：是的，记录在那里，当我CURL
com.basho.riak.client.RiakException: java.io.IOException: <html><head><title>500 Internal Server Error</title></head><body><h1>Internal Server Error</h1>The server encountered an error while processing this request:<br><pre>{error,
{error,
{case_clause,
{error,
{0,
[{module,riak_kv_mrc_map},
{partition,913438523331814323877303020447676887284957839360},
{details,
[{fitting,
{fitting,<0.21083.23>,#Ref<0.0.31.39954>,follow,1}},
{name,0},
{module,riak_kv_mrc_map},
{arg,{{jsfun,<<"Riak.mapValuesJson">>},none}},
{output,
{fitting,<0.21081.23>,#Ref<0.0.31.39954>,sink,
undefined}},
{options,
[{log,sink},
{trace,[error]},
{sink,
{fitting,<0.21081.23>,#Ref<0.0.31.39954>,
sink,undefined}},
{sink_type,{fsm,10,infinity}}]},
{q_limit,64}]},
{type,forward_preflist},
{error,[preflist_exhausted]},
{input,
{ok,{r_object,<<"xxxx-users">>,
<<"xxxx@hotmail.com-userpass">>,
[{r_content,
{dict,7,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],
[],[],[],[]},
{{[],[],
[[<<"Links">>]],
[],[],[],[],[],[],[],
[[<<"content-type">>,97,112,112,108,
105,99,97,116,105,111,110,47,106,
115,111,110],
[<<"X-Riak-VTag">>,54,98,119,73,73,
84,107,120,66,70,107,86,102,67,103,
71,73,116,120,121,85,53]],
[[<<"index">>]],
[],
[[<<"X-Riak-Last-Modified">>|
{1407,514685,380030}]],
[],
[[<<"charset">>,117,116,102,45,56],
[<<"X-Riak-Meta">>]]}}},
<<"{\"identityId\":{\"userId\":\"xxxx@hotmail.com\",\"providerId\":\"userpass\"},\"firstName\":\"xx\",\"lastName\":\"xx\",\"fullName\":\"xx xx\",\"email\":\"xxxx@hotmail.com\",\"authMethod\":{\"method\":\"userPassword\"},\"passwordInfo\":{\"hasher\":\"bcrypt\",\"password\":\"$2a$10$Gm1VVCM09iyI7TQY7r8B7.Baa.YrtHHgREkQpTIH9ThyW4WzuUeJ.\"}}">>}],
[{<<35,9,254,249,83,228,76,146>>,
{1,63574733885}}],
{dict,1,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],[],[],
[],[]},
{{[],[],[],[],[],[],[],[],[],[],[],[],[],[],
[[clean|true]],
[]}}},
undefined},
undefined}},
{modstate,
{state,
913438523331814323877303020447676887284957839360,
{fitting_details,
{fitting,<0.21083.23>,#Ref<0.0.31.39954>,
follow,1},
0,riak_kv_mrc_map,
{{jsfun,<<"Riak.mapValuesJson">>},none},
{fitting,<0.21081.23>,#Ref<0.0.31.39954>,sink,
undefined},
[{log,sink},
{trace,[error]},
{sink,
{fitting,<0.21081.23>,#Ref<0.0.31.39954>,
sink,undefined}},
{sink_type,{fsm,10,infinity}}],
64},
{jsfun,<<"Riak.mapValuesJson">>},
none}},
{stack,[]}]}}},
[{riak_kv_wm_mapred,pipe_mapred_nonchunked,3,
[{file,"src/riak_kv_wm_mapred.erl"},{line,180}]},
{webmachine_resource,resource_call,3,
[{file,"src/webmachine_resource.erl"},{line,183}]},
{webmachine_resource,do,3,
[{file,"src/webmachine_resource.erl"},{line,141}]},
{webmachine_decision_core,resource_call,1,
[{file,"src/webmachine_decision_core.erl"},{line,48}]},
{webmachine_decision_core,decision,1,
[{file,"src/webmachine_decision_core.erl"},{line,481}]},
{webmachine_decision_core,handle_request,2,
[{file,"src/webmachine_decision_core.erl"},{line,33}]},
{webmachine_mochiweb,loop,1,
[{file,"src/webmachine_mochiweb.erl"},{line,97}]},
{mochiweb_http,parse_headers,5,
[{file,"src/mochiweb_http.erl"},{line,180}]}]}}</pre><P><HR><ADDRESS>mochiweb+webmachine web server</ADDRESS></body></html>
at com.basho.riak.client.query.MapReduce.execute(MapReduce.java:81)
at models.UserRecordsModel$.getAllUsers(UserRecordsModel.scala:131)
at controllers.DataRetrieval$$anonfun$getRegisteredUserData$1.apply(DataRetrieval.scala:42)
at controllers.DataRetrieval$$anonfun$getRegisteredUserData$1.apply(DataRetrieval.scala:38)
at play.api.mvc.ActionBuilder$$anonfun$apply$10.apply(Action.scala:221)
at play.api.mvc.ActionBuilder$$anonfun$apply$10.apply(Action.scala:220)
at securesocial.core.SecureSocial$SecuredActionBuilder$$anonfun$2$$anonfun$apply$1.apply(SecureSocial.scala:117)
at securesocial.core.SecureSocial$SecuredActionBuilder$$anonfun$2$$anonfun$apply$1.apply(SecureSocial.scala:113)
at scala.Option.map(Option.scala:145)
at securesocial.core.SecureSocial$SecuredActionBuilder$$anonfun$2.apply(SecureSocial.scala:113)
at securesocial.core.SecureSocial$SecuredActionBuilder$$anonfun$2.apply(SecureSocial.scala:112)
at scala.Option.flatMap(Option.scala:170)
at securesocial.core.SecureSocial$SecuredActionBuilder.invokeSecuredBlock(SecureSocial.scala:112)
at securesocial.core.SecureSocial$SecuredActionBuilder.invokeBlock(SecureSocial.scala:146)
at play.api.mvc.ActionBuilder$$anon$1.apply(Action.scala:309)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:109)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:109)
at play.utils.Threads$.withContextClassLoader(Threads.scala:18)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:108)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:107)
at scala.Option.map(Option.scala:145)
at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:107)
at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:100)
at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:481)
at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:481)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:517)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:517)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$13.apply(Iteratee.scala:493)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$13.apply(Iteratee.scala:493)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:42)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:386)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: java.io.IOException: <html><head><title>500 Internal Server Error</title></head><body><h1>Internal Server Error</h1>The server encountered an error while processing this request:<br><pre>{error,
{error,
{case_clause,
{error,
{0,
[{module,riak_kv_mrc_map},
{partition,913438523331814323877303020447676887284957839360},
{details,
[{fitting,
{fitting,<0.21083.23>,#Ref<0.0.31.39954>,follow,1}},
{name,0},
{module,riak_kv_mrc_map},
{arg,{{jsfun,<<"Riak.mapValuesJson">>},none}},
{output,
{fitting,<0.21081.23>,#Ref<0.0.31.39954>,sink,
undefined}},
{options,
[{log,sink},
{trace,[error]},
{sink,
{fitting,<0.21081.23>,#Ref<0.0.31.39954>,
sink,undefined}},
{sink_type,{fsm,10,infinity}}]},
{q_limit,64}]},
{type,forward_preflist},
{error,[preflist_exhausted]},
{input,
{ok,{r_object,<<"xxxx-users">>,
<<"xxxx@hotmail.com-userpass">>,
[{r_content,
{dict,7,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],
[],[],[],[]},
{{[],[],
[[<<"Links">>]],
[],[],[],[],[],[],[],
[[<<"content-type">>,97,112,112,108,
105,99,97,116,105,111,110,47,106,
115,111,110],
[<<"X-Riak-VTag">>,54,98,119,73,73,
84,107,120,66,70,107,86,102,67,103,
71,73,116,120,121,85,53]],
[[<<"index">>]],
[],
[[<<"X-Riak-Last-Modified">>|
{1407,514685,380030}]],
[],
[[<<"charset">>,117,116,102,45,56],
[<<"X-Riak-Meta">>]]}}},
<<"{\"identityId\":{\"userId\":\"xxxx@hotmail.com\",\"providerId\":\"userpass\"},\"firstName\":\"xx\",\"lastName\":\"xx\",\"fullName\":\"xx xx\",\"email\":\"xxxx@hotmail.com\",\"authMethod\":{\"method\":\"userPassword\"},\"passwordInfo\":{\"hasher\":\"bcrypt\",\"password\":\"$2a$10$Gm1VVCM09iyI7TQY7r8B7.Baa.YrtHHgREkQpTIH9ThyW4WzuUeJ.\"}}">>}],
[{<<35,9,254,249,83,228,76,146>>,
{1,63574733885}}],
{dict,1,16,16,8,80,48,
{[],[],[],[],[],[],[],[],[],[],[],[],[],[],
[],[]},
{{[],[],[],[],[],[],[],[],[],[],[],[],[],[],
[[clean|true]],
[]}}},
undefined},
undefined}},
{modstate,
{state,
913438523331814323877303020447676887284957839360,
{fitting_details,
{fitting,<0.21083.23>,#Ref<0.0.31.39954>,
follow,1},
0,riak_kv_mrc_map,
{{jsfun,<<"Riak.mapValuesJson">>},none},
{fitting,<0.21081.23>,#Ref<0.0.31.39954>,sink,
undefined},
[{log,sink},
{trace,[error]},
{sink,
{fitting,<0.21081.23>,#Ref<0.0.31.39954>,
sink,undefined}},
{sink_type,{fsm,10,infinity}}],
64},
{jsfun,<<"Riak.mapValuesJson">>},
none}},
{stack,[]}]}}},
[{riak_kv_wm_mapred,pipe_mapred_nonchunked,3,
[{file,"src/riak_kv_wm_mapred.erl"},{line,180}]},
{webmachine_resource,resource_call,3,
[{file,"src/webmachine_resource.erl"},{line,183}]},
{webmachine_resource,do,3,
[{file,"src/webmachine_resource.erl"},{line,141}]},
{webmachine_decision_core,resource_call,1,
[{file,"src/webmachine_decision_core.erl"},{line,48}]},
{webmachine_decision_core,decision,1,
[{file,"src/webmachine_decision_core.erl"},{line,481}]},
{webmachine_decision_core,handle_request,2,
[{file,"src/webmachine_decision_core.erl"},{line,33}]},
{webmachine_mochiweb,loop,1,
[{file,"src/webmachine_mochiweb.erl"},{line,97}]},
{mochiweb_http,parse_headers,5,
[{file,"src/mochiweb_http.erl"},{line,180}]}]}}</pre><P><HR><ADDRESS>mochiweb+webmachine web server</ADDRESS></body></html>
at com.basho.riak.client.raw.http.ConversionUtil.convert(ConversionUtil.java:589)
at com.basho.riak.client.raw.http.HTTPClientAdapter.mapReduce(HTTPClientAdapter.java:386)
at com.basho.riak.client.query.MapReduce.execute(MapReduce.java:79)
... 36 more
答案 0 :(得分：2)
堆栈跟踪告诉我们在fie riak_kv_wm_mapred.erl的第180行有一个case子句异常
该行的子句正在处理处理map阶段的管道的响应，该阶段似乎返回错误preflist_exhausted，而case语句没有明确处理该错误。
该错误通常表示一个或多个vnode过载或无法使用，并且回退尚未开始接管其工作负载。
受影响的分区为913438523331814323877303020447676887284957839360，console.log和error.log可能会提供有关所发生情况的更多详细信息。