问题
Can anyone help me solve this problem, I have the stacktrace of the problem, but can't understand what the trace actually means.
The error occurs when I try to retrieve all data from a bucket, in a Riak Database. And I am using java-riak-client library as the ORM. I can figure out that its a MapReduce problem, but other than that.....
Here below is the actual stacktrace, I actually could not figure out what error is it pointing to, and I tried to find out the record its displaying in error. @Update: Yes the record is there, when i 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
回答1:
The stack trace is telling us that there was a case clause exception at line 180 of the fie riak_kv_wm_mapred.erl
The clause at that line is handling the responses for the pipe processing the map phase, which appears to be returning the error preflist_exhausted, which is not explicitly handled by the case statement.
That error usually indicates that one or more vnodes were overloaded or otherwise unavailable, and fallbacks had not yet started to take over their workload.
The affected partition was 913438523331814323877303020447676887284957839360, the console.log and error.log may have further details about what happened.
来源：https://stackoverflow.com/questions/25277718/how-to-understand-this-riak-stacktrace