我试图使用elephantbird json加载程序解析下面的输入（这个输入中有2条记录）
[{“node_disk_lnum_1”：36，“node_disk_xfers_in_rate_sum”：136.40000000000001，“node_disk_bytes_in_rate_22”：187392.0，“node_disk_lnum_7”：13}]
[{“node_disk_lnum_1”：36，“node_disk_xfers_in_rate_sum”：105.2，“node_disk_bytes_in_rate_22”：123084.8，“node_disk_lnum_7”：13}]
以下是我的语法：

register '/home/data/Desktop/elephant-bird-pig-4.1.jar';

a = LOAD '/pig/tc1.log' USING 
com.twitter.elephantbird.pig.load.JsonLoader('-nestedLoad') as (json:map[]);

b = FOREACH a GENERATE flatten(json#'node_disk_lnum_1') AS 
node_disk_lnum_1,flatten(json#'node_disk_xfers_in_rate_sum') AS 
node_disk_xfers_in_rate_sum,flatten(json#'node_disk_bytes_in_rate_22') AS 
node_disk_bytes_in_rate_22, flatten(json#'node_disk_lnum_7') AS
node_disk_lnum_7;

DESCRIBE b;

b描述结果：
b:{节点磁盘1:bytearray，节点磁盘7:bytearray}

c = FOREACH b GENERATE node_disk_lnum_1;

DESCRIBE c;

c:{node\u disk\u lnum\u 1:bytearray}

DUMP c;

预期结果：
36, 136.40000000000001, 187392.0, 13
36, 105.2, 123084.8, 13
抛出下面的错误
2017-02-06 01:05:49337[main]info org.apache.pig.tools.pigstats.scriptstate-脚本中使用的pig功能：未知2017-02-06 01:05:49386[main]info org.apache.pig.data.schematuplebackend-未设置键[pig.schematuple]。。。不会生成代码。2017-02-06 01:05:49387[main]info org.apache.pig.newplan.logical.optimizer.logicalplanoptimizer-{rules\u enabled=[addforeach，columnmapkeyprune，constantcalculator，groupbyconstparallelsetter，limitoptimizer，loadtypecastinerter，mergefilter，mergeforeach，partitionfilteroptimizer，predicatepushdownownoptimizer，pushdownforeachflatten，pushupfilter，splitfilter，streamtypecastinerter]}2017-02-06 01:05:49390[main]info org.apache.pig.newplan.logical.rules.columnprunevisitor-Map键：$0->[node\u disk\u lnum\u 1，node\u disk\u xfers\u in \u rate\u sum，node\u disk\u bytes\u in \u rate\u 22，node\u disk\lnum\u 7]
2017-02-06 01:05:49395[main]info org.apache.pig.backend.hadoop.executionengine.mapreducelayer.mrcompiler-文件连接阈值：100？false 2017-02-06 01:05:49398[main]info org.apache.pig.backend.hadoop.executionengine.mapreducelayer.multiqueryoptimizer-优化前mr计划大小：1 2017-02-06 01:05:49398[main]info org.apache.pig.backend.hadoop.executionengine.mapreducelayer.multiqueryoptimizer-优化后mr计划大小：1 2017-02-06 01:05:49，425[main]info org.apache.pig.tools.pigstats.mapreduce.mrscriptstate-pig脚本设置已添加到作业2017-02-06 01:05:49426[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 2017-02-06 01:05:49，428[main]error org.apache.pig.tools.grunt.grunt-错误2998:未处理的内部错误。com/twitter/elephantbird/util/hadoopcompat
请帮帮我，我错过了什么？