Apache PIG、ELEPHANTBIRDJSON 加载器

Question

我正在尝试使用 Elephantbird json 加载程序

解析以下输入（此输入中有 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}]

这是我的语法：

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: {node_disk_lnum_1: bytearray,node_disk_xfers_in_rate_sum: bytearray,node_disk_bytes_in_rate_22: bytearray,node_disk_lnum_7: bytearray}

c = FOREACH b GENERATE node_disk_lnum_1;

DESCRIBE c;

c: {node_disk_lnum_1: bytearray}

DUMP c;

预期结果：

36, 136.40000000000001, 187392.0, 13

36, 105.2, 123084.8, 13

抛出以下错误

2017-02-06 01:05:49,337 [main] INFO org.apache.pig.tools.pigstats.ScriptState - Pig features used in the script: UNKNOWN 2017-02-06 01:05:49,386 [main] INFO org.apache.pig.data.SchemaTupleBackend - Key [pig.schematuple] was not set... will not generate code. 2017-02-06 01:05:49,387 [main] INFO org.apache.pig.newplan.logical.optimizer.LogicalPlanOptimizer - {RULES_ENABLED=[AddForEach, ColumnMapKeyPrune, ConstantCalculator, GroupByConstParallelSetter, LimitOptimizer, LoadTypeCastInserter, MergeFilter, MergeForEach, PartitionFilterOptimizer, PredicatePushdownOptimizer, PushDownForEachFlatten, PushUpFilter, SplitFilter, StreamTypeCastInserter]} 2017-02-06 01:05:49,390 [main] INFO org.apache.pig.newplan.logical.rules.ColumnPruneVisitor - Map key required for a: [=17=]->[node_disk_lnum_1, node_disk_xfers_in_rate_sum, node_disk_bytes_in_rate_22, node_disk_lnum_7]

2017-02-06 01:05:49,395 [main] INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRCompiler - File concatenation threshold: 100 optimistic? false 2017-02-06 01:05:49,398 [main] INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer - MR plan size before optimization: 1 2017-02-06 01:05:49,398 [main] INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MultiQueryOptimizer - MR plan size after optimization: 1 2017-02-06 01:05:49,425 [main] INFO org.apache.pig.tools.pigstats.mapreduce.MRScriptState - Pig script settings are added to the job 2017-02-06 01:05:49,426 [main] INFO org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.JobControlCompiler - mapred.job.reduce.markreset.buffer.percent is not set, set to default 0.3 2017-02-06 01:05:49,428 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 2998: Unhandled internal error. com/twitter/elephantbird/util/HadoopCompat

请帮忙看看我遗漏了什么？

Answer 1

您的 json 中没有任何嵌套数据，因此删除 -nestedload

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

Apache PIG、ELEPHANTBIRDJSON 加载器

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