Error running Hive query with JSON data? - json

Question

I have data containing the following:
{"field1":{"data1": 1},"field2":100,"field3":"more data1","field4":123.001}
{"field1":{"data2": 1},"field2":200,"field3":"more data2","field4":123.002}
{"field1":{"data3": 1},"field2":300,"field3":"more data3","field4":123.003}
{"field1":{"data4": 1},"field2":400,"field3":"more data4","field4":123.004}
I uploaded it to S3 and converted it to a Hive table using the following from the Hive console:
ADD JAR s3://elasticmapreduce/samples/hive-ads/libs/jsonserde.jar;
CREATE EXTERNAL TABLE impressions (json STRING ) ROW FORMAT DELIMITED LINES TERMINATED BY '\n' LOCATION 's3://my-bucket/';
The query:
SELECT * FROM impressions;
gives output fine but as soon as I try and use the get_json_object UDF
and run the query:
SELECT get_json_object(impressions.json, '$.field2') FROM impressions;
I get the following error:
> SELECT get_json_object(impressions.json, '$.field2') FROM impressions;
Total MapReduce jobs = 1
Launching Job 1 out of 1
Number of reduce tasks is set to 0 since there's no reduce operator
java.io.IOException: cannot find dir = s3://nick.bucket.dev/snapshot.csv in pathToPartitionInfo: [s3://nick.bucket.dev/]
at org.apache.hadoop.hive.ql.io.HiveFileFormatUtils.getPartitionDescFromPathRecursively(HiveFileFormatUtils.java:291)
at org.apache.hadoop.hive.ql.io.HiveFileFormatUtils.getPartitionDescFromPathRecursively(HiveFileFormatUtils.java:258)
at org.apache.hadoop.hive.ql.io.CombineHiveInputFormat$CombineHiveInputSplit.<init>(CombineHiveInputFormat.java:108)
at org.apache.hadoop.hive.ql.io.CombineHiveInputFormat.getSplits(CombineHiveInputFormat.java:423)
at org.apache.hadoop.mapred.JobClient.writeOldSplits(JobClient.java:1036)
at org.apache.hadoop.mapred.JobClient.writeSplits(JobClient.java:1028)
at org.apache.hadoop.mapred.JobClient.access$700(JobClient.java:172)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:944)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:897)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:396)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1059)
at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:897)
at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:871)
at org.apache.hadoop.hive.ql.exec.ExecDriver.execute(ExecDriver.java:479)
at org.apache.hadoop.hive.ql.exec.MapRedTask.execute(MapRedTask.java:136)
at org.apache.hadoop.hive.ql.exec.Task.executeTask(Task.java:133)
at org.apache.hadoop.hive.ql.exec.TaskRunner.runSequential(TaskRunner.java:57)
at org.apache.hadoop.hive.ql.Driver.launchTask(Driver.java:1332)
at org.apache.hadoop.hive.ql.Driver.execute(Driver.java:1123)
at org.apache.hadoop.hive.ql.Driver.run(Driver.java:931)
at org.apache.hadoop.hive.cli.CliDriver.processLocalCmd(CliDriver.java:261)
at org.apache.hadoop.hive.cli.CliDriver.processCmd(CliDriver.java:218)
at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:409)
at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:684)
at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:567)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.util.RunJar.main(RunJar.java:156)
Job Submission failed with exception 'java.io.IOException(cannot find dir = s3://my-bucket/snapshot.csv in pathToPartitionInfo: [s3://my-bucket/])'
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.MapRedTask
Does anyone know what is wrong?

Answer 1

Any reason why you are declaring:
ADD JAR s3://elasticmapreduce/samples/hive-ads/libs/jsonserde.jar;
But not using the serde in your table definition? See the code snippet below on how to use it. I can't see any reason to use get_json_object here.
CREATE EXTERNAL TABLE impressions (
field1 string, field2 string, field3 string, field4 string
)
ROW FORMAT
serde 'com.amazon.elasticmapreduce.JsonSerde'
with serdeproperties ( 'paths'='field1, field2, field3,
field4)
LOCATION 's3://mybucket' ;