question Re: Hive reflect function is not allowed in Archives of Support Questions (Read Only)

Hive reflect function is not allowed

TeeupData — Thu, 11 Feb 2016 12:01:31 GMT

on Sandbox 2.3.2, the following hive query errors out:

SELECT reflect("java.lang.String", "valueOf", 1), reflect("java.lang.String", "isEmpty"), reflect("java.lang.Math", "max", 2, 3), reflect("java.lang.Math", "min", 2, 3), reflect("java.lang.Math", "round", 2.5), reflect("java.lang.Math", "exp", 1.0), reflect("java.lang.Math", "floor", 1.9) FROM hyhelp LIMIT 1;

error message is:

Error while compiling statement: FAILED: SemanticException UDF reflect is not allowed

hiveserver2.log shows:

2016-02-10 22:51:23,461 ERROR [HiveServer2-Handler-Pool: Thread-46]: ql.Driver (SessionState.java:printError(960)) - FAILED: SemanticException UDF reflect is not allowed org.apache.hadoop.hive.ql.parse.SemanticException: UDF reflect is not allowed at org.apache.hadoop.hive.ql.exec.Registry.getFunctionInfo(Registry.java:245) at org.apache.hadoop.hive.ql.exec.FunctionRegistry.getFunctionInfo(FunctionRegistry.java:463) at org.apache.hadoop.hive.ql.exec.FunctionRegistry.impliesOrder(FunctionRegistry.java:1521) at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.doPhase1GetAllAggregations(SemanticAnalyzer.java:530) at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.doPhase1GetAggregationsFromSelect(SemanticAnalyzer.java:465) at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.doPhase1(SemanticAnalyzer.java:1145) at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.doPhase1(SemanticAnalyzer.java:1415) at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.doPhase1(SemanticAnalyzer.java:1415) at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genResolvedParseTree(SemanticAnalyzer.java:10048) at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.analyzeInternal(SemanticAnalyzer.java:10106) at org.apache.hadoop.hive.ql.parse.CalcitePlanner.analyzeInternal(CalcitePlanner.java:211) at org.apache.hadoop.hive.ql.parse.BaseSemanticAnalyzer.analyze(BaseSemanticAnalyzer.java:227) at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:424)

....

Is this a configuration issue or there are jar files missing?

Thanks

Re: Hive reflect function is not allowed

pminovic — Thu, 11 Feb 2016 16:23:43 GMT

Hi @Herman Yu, on my Sandbox, also HDP-2.3.2 it works, I only changed table name:

hive> SELECT reflect("java.lang.String", "valueOf", 1), reflect("java.lang.String", "isEmpty"), reflect("java.lang.Math", "max", 2, 3), reflect("java.lang.Math", "min", 2, 3), reflect("java.lang.Math", "round", 2.5), reflect("java.lang.Math", "exp", 1.0), reflect("java.lang.Math", "floor", 1.9) FROM st2 limit 1;
OK
1	true	3	2	3	2.718281828459045	1.0
Time taken: 1.97 seconds, Fetched: 1 row(s)

Do other Hive commands and scripts work? Can you try reflect one by one, or, if you copy/pasted the command from somewhere try typing the first reflect.

Re: Hive reflect function is not allowed

lprisock — Fri, 12 Feb 2016 03:24:42 GMT

Does not work for me either.

Re: Hive reflect function is not allowed

TeeupData — Fri, 12 Feb 2016 09:04:48 GMT

Thanks, I think it is a configuration issue. it doesn't work with a customized Hue I installed, doesn't work with Ambari Hive view either, but does work with Hive CLI. I found a walk-around for now, will figure out the configurations later when have time.

thanks.

Re: Hive reflect function is not allowed

pminovic — Mon, 19 Aug 2019 08:46:59 GMT

It also works with standard Hue-2.6.1 packaged with HDP-2.3.4 (that's the only one I can try; it should also work with Hue coming with 2.3.2 because it's the same version), I tried:

SELECT reflect("java.lang.Math","exp",2.0), reflect("java.lang.Math","hypot",3.0,4.0) from t2 limit 1;

Re: Hive reflect function is not allowed

lprisock — Sat, 13 Feb 2016 02:33:11 GMT

I am still unable to get this to work. All I am doing is trying to run the query, is there something I need to do in order to get this to work?