Apache pig 清管器：说明错误2997

下面的代码运行良好，并在grunt（本地模式）下生成结果，但上一个关系中的插图给出了错误2997

/*在本地模式下打开Grunt清管器-x本地*/

STOCK_A= LOAD '/media/sf_sand/NYSE_daily_prices_A.csv' USING PigStorage(',') AS (exchange:chararray,symbol:chararray,date:chararray,open:float,high:float,low:float,close:float,volume:int,adj_close:float); 
describe STOCK_A;
illustrate STOCK_A;
b= LIMIT STOCK_A 100;
describe b;
illustrate b;
c= FOREACH b GENERATE *;
illustrate c is working
c= FOREACH b GENERATE symbol,date,close;
dump c;  — working

下面是错误说明c不工作（错误2997遇到IO异常）：

015-06-10 11:52:23621[main]INFO org.apache.pig.backend.hadoop.executionengine.HExecutionEngine-连接到hadoop文件系统的位置：file:///
2015-06-10 11:52:23647[main]WARN org.apache.pig.data.SchemaTupleBackend-SchemaTupleBackend已初始化
2015-06-10 11:52:23647[main]INFO org.apache.pig.newplan.logic.optimizer.LogicalPlanOptimizer-{启用规则=[ConstantCalculator，LoadTypeCastInserter，PredicatePushdownOptimizer，StreamTypeCastInserter]，禁用规则=[AddForEach、ColumnMapKeyPrune、GroupByConstParallelSetter、LimitOptimizer、MergeFilter、MergeForEach、PartitionFilterOptimizer、PushDownForEachFlatte、PushUpFilter、SplitFilter]}
2015-06-10 11:52:23650[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRCompiler-文件连接阈值：100乐观？错误
2015-06-10 11:52:23650[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer-优化前的MR计划大小：1
2015-06-10 11:52:23650[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer-优化后的MR计划大小：1
2015-06-10 11:52:23651[main]INFO org.apache.pig.tools.pigstats.mapreduce.MRScriptState-将pig脚本设置添加到作业中
2015-06-10 11:52:23651[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler-mapred.job.reduce.markreset.buffer.percent未设置，设置为默认值0.3
2015-06-10 11:52:23658[main]INFO org.apache.pig.data.SchemaTupleFrontend-键[pig.schematuple]为false，将不会生成代码。
2015-06-10 11:52:23658[main]INFO org.apache.pig.data.SchemaTupleFrontend-开始将生成的代码移动到分布式cacche的过程
2015-06-10 11:52:23658[main]INFO org.apache.pig.data.SchemaTupleFrontend-本地模式下不支持或不需要分布式缓存。使用代码临时目录设置键[pig.schematuple.local.dir]：tmp/1433937143658-0
2015-06-10 11:52:23667[main]INFO org.apache.pig.data.SchemaTupleBackend-未设置键[pig.schematuple]…将不会生成代码。
2015-06-10 11:52:23669[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapOnly$Map-每个作业阶段处理的别名（别名[行，偏移]）：M:STOCK_A[3,9]C:R:
2015-06-10 11:52:23672[main]INFO org.apache.hadoop.mapreduce.lib.input.FileInputFormat-处理的总输入路径：1
2015-06-10 11:52:23672[main]INFO org.apache.pig.backend.hadoop.executionengine.util.MapRedUtil-进程的总输入路径：1
2015-06-10 11:52:23705[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRCompiler-文件连接阈值：100乐观？错误
2015-06-10 11:52:23707[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer-优化前的MR计划大小：1
2015-06-10 11:52:23707[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer-优化后的MR计划大小：1
2015-06-10 11:52:23708[main]INFO org.apache.pig.tools.pigstats.mapreduce.MRScriptState-将pig脚本设置添加到作业中
2015-06-10 11:52:23708[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler-mapred.job.reduce.markreset.buffer.percent未设置，设置为默认值0.3
2015-06-10 11:52:23708[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler-检测到的缩减阶段，估计所需的缩减器。
2015-06-10 11:52:23709[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler-将并行度设置为1
2015-06-10 11:52:23723[main]WARN org.apache.pig.data.SchemaTupleBackend-SchemaTupleBackend已初始化
2015-06-10 11:52:23727[main]INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Map-每个作业阶段正在处理的别名（别名名称[行，偏移量]）：M:STOCK_A[3,9]，STOCK_A[-1，-1]，c[8,3]c:R:b[4,3]
2015-06-10 11:52:23727[main]WARN org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger-org.apache.pig.builtin.Utf8StorageConverter（字段_丢弃_类型_转换_失败）：无法解释值[115、116、111、99、107、95、112、114、105、99、101、95、111、101、110]在转换为float的字段中，捕获的NumberFormatException字段被丢弃
2015-06-10 11:52:23727[main]WARN org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger-org.apache.pig.builtin.Utf8StorageConverter（字段_丢弃_类型_转换_失败）：无法解释值[115、116、111、99、107、95、112、114、105、99、101、95、104、105、103、104]在转换为float的字段中，捕获的NumberFormatException字段被丢弃
2015-06-10 11:52:23727[main]WARN org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger-org.apache.pig.builtin.Utf8StorageConverter（字段_丢弃_类型_转换_失败）：无法解释值[115、116、111、99、107、95、112、114、105、99、101、95、108、111、119]在转换为float的字段中，捕获的NumberFormatException字段被丢弃
2015-06-10 11:52:23727[main]WARN org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger-org.apache.pig.builtin.Utf8StorageConverter（字段_丢弃_类型_转换_失败）：无法解释值[115、116、111、99、107、95、112、114、105、99、101、95、99、108、111、115、101]在转换为float的字段中，捕获的NumberFormatException字段被丢弃
2015-06-10 11:52:23727[main]警告org.apache.pig.backend.had
015-06-10 11:52:23,621 [main] INFO  org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: file:///
2015-06-10 11:52:23,647 [main] WARN  org.apache.pig.data.SchemaTupleBackend - SchemaTupleBackend has already been initialized
2015-06-10 11:52:23,647 [main] INFO  org.apache.pig.newplan.logical.optimizer.LogicalPlanOptimizer - {RULES_ENABLED=[ConstantCalculator, LoadTypeCastInserter, PredicatePushdownOptimizer, StreamTypeCastInserter], RULES_DISABLED=[AddForEach, ColumnMapKeyPrune, GroupByConstParallelSetter, LimitOptimizer, MergeFilter, MergeForEach, PartitionFilterOptimizer, PushDownForEachFlatten, PushUpFilter, SplitFilter]}
2015-06-10 11:52:23,650 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRCompiler - File concatenation threshold: 100 optimistic? false
2015-06-10 11:52:23,650 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer - MR plan size before optimization: 1
2015-06-10 11:52:23,650 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer - MR plan size after optimization: 1
2015-06-10 11:52:23,651 [main] INFO  org.apache.pig.tools.pigstats.mapreduce.MRScriptState - Pig script settings are added to the job
2015-06-10 11:52:23,651 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - mapred.job.reduce.markreset.buffer.percent is not set, set to default 0.3
2015-06-10 11:52:23,658 [main] INFO  org.apache.pig.data.SchemaTupleFrontend - Key [pig.schematuple] is false, will not generate code.
2015-06-10 11:52:23,658 [main] INFO  org.apache.pig.data.SchemaTupleFrontend - Starting process to move generated code to distributed cacche
2015-06-10 11:52:23,658 [main] INFO  org.apache.pig.data.SchemaTupleFrontend - Distributed cache not supported or needed in local mode. Setting key [pig.schematuple.local.dir] with code temp directory: /tmp/1433937143658-0
2015-06-10 11:52:23,667 [main] INFO  org.apache.pig.data.SchemaTupleBackend - Key [pig.schematuple] was not set... will not generate code.
2015-06-10 11:52:23,669 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapOnly$Map - Aliases being processed per job phase (AliasName[line,offset]): M: STOCK_A[3,9] C:  R:
2015-06-10 11:52:23,672 [main] INFO  org.apache.hadoop.mapreduce.lib.input.FileInputFormat - Total input paths to process : 1
2015-06-10 11:52:23,672 [main] INFO  org.apache.pig.backend.hadoop.executionengine.util.MapRedUtil - Total input paths to process : 1
2015-06-10 11:52:23,705 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRCompiler - File concatenation threshold: 100 optimistic? false
2015-06-10 11:52:23,707 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer - MR plan size before optimization: 1
2015-06-10 11:52:23,707 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer - MR plan size after optimization: 1
2015-06-10 11:52:23,708 [main] INFO  org.apache.pig.tools.pigstats.mapreduce.MRScriptState - Pig script settings are added to the job
2015-06-10 11:52:23,708 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - mapred.job.reduce.markreset.buffer.percent is not set, set to default 0.3
2015-06-10 11:52:23,708 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - Reduce phase detected, estimating # of required reducers.
2015-06-10 11:52:23,709 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - Setting Parallelism to 1
2015-06-10 11:52:23,723 [main] WARN  org.apache.pig.data.SchemaTupleBackend - SchemaTupleBackend has already been initialized
2015-06-10 11:52:23,727 [main] INFO  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapReduce$Map - Aliases being processed per job phase (AliasName[line,offset]): M: STOCK_A[3,9],STOCK_A[-1,-1],c[8,3] C:  R: b[4,3]
2015-06-10 11:52:23,727 [main] WARN  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger - org.apache.pig.builtin.Utf8StorageConverter(FIELD_DISCARDED_TYPE_CONVERSION_FAILED): Unable to interpret value [115, 116, 111, 99, 107, 95, 112, 114, 105, 99, 101, 95, 111, 112, 101, 110] in field being converted to float, caught NumberFormatException <For input string: "stock_price_open"> field discarded
2015-06-10 11:52:23,727 [main] WARN  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger - org.apache.pig.builtin.Utf8StorageConverter(FIELD_DISCARDED_TYPE_CONVERSION_FAILED): Unable to interpret value [115, 116, 111, 99, 107, 95, 112, 114, 105, 99, 101, 95, 104, 105, 103, 104] in field being converted to float, caught NumberFormatException <For input string: "stock_price_high"> field discarded
2015-06-10 11:52:23,727 [main] WARN  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger - org.apache.pig.builtin.Utf8StorageConverter(FIELD_DISCARDED_TYPE_CONVERSION_FAILED): Unable to interpret value [115, 116, 111, 99, 107, 95, 112, 114, 105, 99, 101, 95, 108, 111, 119] in field being converted to float, caught NumberFormatException <For input string: "stock_price_low"> field discarded
2015-06-10 11:52:23,727 [main] WARN  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger - org.apache.pig.builtin.Utf8StorageConverter(FIELD_DISCARDED_TYPE_CONVERSION_FAILED): Unable to interpret value [115, 116, 111, 99, 107, 95, 112, 114, 105, 99, 101, 95, 99, 108, 111, 115, 101] in field being converted to float, caught NumberFormatException <For input string: "stock_price_close"> field discarded
2015-06-10 11:52:23,727 [main] WARN  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger - org.apache.pig.builtin.Utf8StorageConverter(FIELD_DISCARDED_TYPE_CONVERSION_FAILED): Unable to interpret value [115, 116, 111, 99, 107, 95, 118, 111, 108, 117, 109, 101] in field being converted to int, caught NumberFormatException <For input string: "stock_volume"> field discarded
2015-06-10 11:52:23,727 [main] WARN  org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigHadoopLogger - org.apache.pig.builtin.Utf8StorageConverter(FIELD_DISCARDED_TYPE_CONVERSION_FAILED): Unable to interpret value [115, 116, 111, 99, 107, 95, 112, 114, 105, 99, 101, 95, 97, 100, 106, 95, 99, 108, 111, 115, 101] in field being converted to float, caught NumberFormatException <For input string: "stock_price_adj_close"> field discarded
java.lang.ClassCastException
2015-06-10 11:52:23,727 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 2997: Encountered IOException. Exception

Unable to interpret value [115, 116, 111, 99, 107, 95, 112, 114, 105, 99, 101, 95, 97, 100, 106, 95, 99, 108, 111, 115, 101] in field being converted to float, caught NumberFormatException field discarded java.lang.ClassCastException 2015-06-10 11:52:23,727 [main]