Well, it's not throwing me errors anymore. Now it's just discarding the field. When I run it on two records where I've verified a field exists in the json, I get:

Encountered Warning FIELD_DISCARDED_TYPE_CONVERSION_FAILED 2 time(s).

More specifically, my json is of the following form:

{"foo":0,"bar":"hi"}

On that, I'm running:

initial = LOAD 'some_file.lzo' USING com.twitter.elephantbird.pig.store.LzoPigStorage('\\t') AS (col1, col2, col3, json_data);
extracted = FOREACH initial GENERATE (chararray) json_data#'type' AS type;
dump extracted;

Which gives me the above warning along with:

()
()

I also tried it without the cast to chararray, but received the same results. Should I be casting json_data as some other data type when I load it initially? Seems by default it's cast to a bytearray when I describe initial. Would that be a problem?

Thanks for all the help so far!

Eli



On 9/12/11 9:26 PM, Dmitriy Ryaboy wrote:
Ah yeah that's my favorite thing about Pig maps (prior to pig 0.9,
theoretically).
The values are bytearrays. You are probably trying to treat them as strings.
  You have to do stuff like this:

x = foreach myrelation generate
   (chararray) mymap#'foo' as foo,
   (chararray) mymap#'bar' as bar;


On Mon, Sep 12, 2011 at 11:54 AM, Eli Finkelshteyn<[email protected]>  wrote:

Hmmm, now it gets past my mention of the function, but when I run a dump on
generated information, I get:

2011-09-12 14:48:12,814 [main] ERROR org.apache.pig.tools.grunt.**Grunt -
ERROR 2997: Unable to recreate exception from backed error:
java.lang.ClassCastException: *org.apache.pig.data.**DataByteArray cannot
be cast to java.lang.String*

Thanks for all the help so far!

Eli


On 9/12/11 2:42 PM, Dmitriy Ryaboy wrote:

You also want json-simple-1.1.jar


On Mon, Sep 12, 2011 at 10:46 AM, Eli 
Finkelshteyn<iefinkel@gmail.**com<[email protected]>
wrote:
  Hmm, I'm loading up hadoop-lzo.*.jar, elephant-bird.*.jar, guava-*.jar,
and
piggybank.jar, and then trying to use that UDF, but getting the following
error:

ERROR 2998: Unhandled internal error. org/json/simple/parser/**
ParseException

java.lang.****NoClassDefFoundError: org/json/simple/parser/****
ParseException
        at java.lang.Class.forName0(****Native Method)
        at java.lang.Class.forName(Class.****java:247)
        at org.apache.pig.impl.****PigContext.resolveClassName(**
PigContext.java:426)
        at org.apache.pig.impl.****PigContext.****
instantiateFuncFromSpec(**
PigContext.java:456)
        at org.apache.pig.impl.****PigContext.****
instantiateFuncFromSpec(**
PigContext.java:508)
        at org.apache.pig.impl.****PigContext.****
instantiateFuncFromAlias(**
PigContext.java:531)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.EvalFuncSpec(****QueryParser.java:5462)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.BaseEvalSpec(****QueryParser.java:5291)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.UnaryExpr(****QueryParser.java:5187)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.CastExpr(****QueryParser.java:5133)
        at org.apache.pig.impl.****logicalLayer.parser.****QueryParser.**
MultiplicativeExpr(****QueryParser.java:5042)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.AdditiveExpr(****QueryParser.java:4968)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.InfixExpr(****QueryParser.java:4934)
        at org.apache.pig.impl.****logicalLayer.parser.****QueryParser.**
FlattenedGenerateItem(****QueryParser.java:4861)
        at org.apache.pig.impl.****logicalLayer.parser.****QueryParser.**
FlattenedGenerateItemList(****QueryParser.java:4747)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.GenerateStatement(****QueryParser.java:4704)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.NestedBlock(****QueryParser.java:4030)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.ForEachClause(****QueryParser.java:3433)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.BaseExpr(****QueryParser.java:1464)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.Expr(QueryParser.****java:1013)
        at org.apache.pig.impl.****logicalLayer.parser.**
QueryParser.Parse(QueryParser.****java:800)
        etc...

Any ideas? I've verified that it recognizes the function itself, and that
the data it's running on is valid json. Not sure what else I can check.

Eli



On 9/9/11 7:13 PM, Dmitriy Ryaboy wrote:

  They derive from the same classes as far as lzo handling goes, so I
suspect
something's up with your environment or inputs if you get
LzoTokenizedLoader
to work, but LzoJsonStorage does not.

Note that LzoTokenizedLoader is deprecated -- just use LzoPigStorage.

JsonLoader wouldn't work for you because it expects the complete input
line
to be json, not part of it. You want to load with LzoPigStorage, and
then
apply the JsonStringToMap udf to the third field.

-D


On Fri, Sep 9, 2011 at 3:49 PM, Eli Finkelshteyn<iefinkel@gmail.****
com<[email protected]>>

  wrote:

  Hi,

I'm currently working on trying to load lzos that contain some JSON
elements. This is of the form:

item1    item2    {'thing1':'1','thing2':'2'}
item3    item4    {'thing3':'1','thing27':'2'}
item5    item6    {'thing5':'1','thing19':'2'}

I was thinking I could use LzoJsonLoader for this, but it keeps
throwing
me
errors like:
ERROR com.hadoop.compression.lzo.******LzoCodec - Cannot load
native-lzo
without native-hadoop

This is despite the fact that I can load normal lzos just fine using
LzoTokenizedLoader('\\t'). So, now I'm at a bit of a standstill. What
should
I do to go about loading these files? Does anyone have any ideas?

Cheers,
Eli




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