我试图分析apache日志，目标是找出所有用户代理及其使用百分比。当结果包含每个useragent、count和percentage时，下面的程序可以正常工作。当程序试图按最常用的顺序排序时，在最后一行失败。有人能帮忙吗？

logs = LOAD '$LOGS' USING ApacheCombinedLogLoader AS (remoteHost, hyphen, user, time, method, uri, protocol, statusCode, responseSize, referer, userAgent);

uarows = FOREACH logs GENERATE userAgent;
total = FOREACH (GROUP uarows ALL) GENERATE COUNT(uarows) as count;
dump total; 

gpuarows = GROUP uarows BY userAgent;
result = FOREACH gpuarows {
       subtotal = COUNT(uarows);
       GENERATE flatten(group) as ua, subtotal AS SUB_TOTAL, 100*(double)subtotal/(double)total.count AS percentage;
       };
orderresult = ORDER result BY SUB_TOTAL DESC;
dump orderresult;

奇怪的是“dump result”工作正常，所以订单行会制造麻烦
错误：

013-04-13 11:33:09,976 [Thread-48] INFO  org.apache.hadoop.mapred.MapTask - data buffer = 79691776/99614720
2013-04-13 11:33:09,976 [Thread-48] INFO  org.apache.hadoop.mapred.MapTask - record buffer = 262144/327680
2013-04-13 11:33:09,995 [Thread-48] WARN  org.apache.hadoop.mapred.LocalJobRunner - job_local_0005
java.lang.RuntimeException: org.apache.hadoop.mapreduce.lib.input.InvalidInputException: Input path does not exist: file:/home/dliu/ApacheLogAnalysisWithPig/pigsample_1573648613_1365823989735
    at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.partitioners.WeightedRangePartitioner.setConf(WeightedRangePartitioner.java:157)
    at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:62)
    at org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:117)
    at org.apache.hadoop.mapred.MapTask$NewOutputCollector.<init>(MapTask.java:677)
    at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:756)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
    at org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:212)
Caused by: org.apache.hadoop.mapreduce.lib.input.InvalidInputException: Input path does not exist: file:/home/dliu/ApacheLogAnalysisWithPig/pigsample_1573648613_1365823989735
    at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.listStatus(FileInputFormat.java:235)
    at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigFileInputFormat.listStatus(PigFileInputFormat.java:37)
    at org.apache.hadoop.mapreduce.lib.input.FileInputFormat.getSplits(FileInputFormat.java:252)
    at org.apache.pig.impl.io.ReadToEndLoader.init(ReadToEndLoader.java:177)
    at org.apache.pig.impl.io.ReadToEndLoader.<init>(ReadToEndLoader.java:124)
    at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.partitioners.WeightedRangePartitioner.setConf(WeightedRangePartitioner.java:131)
    ... 6 more
2013-04-13 11:33:10,276 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - HadoopJobId: job_local_0005
2013-04-13 11:33:10,276 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Processing aliases orderresult
2013-04-13 11:33:10,276 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - detailed locations: M: orderresult[16,14] C:  R: 
2013-04-13 11:33:15,286 [main] WARN  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Ooops! Some job has failed! Specify -stop_on_failure if you want Pig to stop immediately on failure.
2013-04-13 11:33:15,286 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - job job_local_0005 has failed! Stop running all dependent jobs
2013-04-13 11:33:15,287 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - 100% complete
2013-04-13 11:33:15,287 [main] ERROR org.apache.pig.tools.pigstats.PigStatsUtil - 1 map reduce job(s) failed!
2013-04-13 11:33:15,288 [main] INFO  org.apache.pig.tools.pigstats.SimplePigStats - Script Statistics: 

HadoopVersion   PigVersion  UserId  StartedAt   FinishedAt  Features
1.0.4   0.11.0  dliu    2013-04-13 11:32:27 2013-04-13 11:33:15 GROUP_BY,ORDER_BY

Some jobs have failed! Stop running all dependent jobs

Job Stats (time in seconds):
JobId   Maps    Reduces MaxMapTime  MinMapTIme  AvgMapTime  MedianMapTime   MaxReduceTime   MinReduceTime   AvgReduceTime   MedianReducetime    Alias   Feature Outputs
job_local_0002  1   1   n/a n/a n/a n/a n/a n/a 1-18,logs,total,uarows  MULTI_QUERY,COMBINER    
job_local_0003  1   1   n/a n/a n/a n/a n/a n/a gpuarows,result GROUP_BY,COMBINER   
job_local_0004  1   1   n/a n/a n/a n/a n/a n/a orderresult SAMPLER 

Failed Jobs:
JobId   Alias   Feature Message Outputs
job_local_0005  orderresult ORDER_BY    Message: Job failed! Error - NA file:/tmp/temp265162785/tmp896004388,

Input(s):
Successfully read 0 records from: "file:///home/dliu/ApacheLogAnalysisWithPig/access.log"

Output(s):
Failed to produce result in "file:/tmp/temp265162785/tmp896004388"

Counters:
Total records written : 0
Total bytes written : 0
Spillable Memory Manager spill count : 0
Total bags proactively spilled: 0
Total records proactively spilled: 0

Job DAG:
job_local_0002  ->  job_local_0003,
job_local_0003  ->  job_local_0004,
job_local_0004  ->  job_local_0005,
job_local_0005

2013-04-13 11:33:15,291 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MapReduceLauncher - Some jobs have failed! Stop running all dependent jobs
2013-04-13 11:33:15,297 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 1066: Unable to open iterator for alias orderresult
Details at logfile: /home/dliu/ApacheLogAnalysisWithPig/pig_1365823931459.log