Re: handling null argument in custom udf
Right. Thanks for all the help.
It turned out that it did help to check for null in the code. No mystery.
I did try that earlier but the attempt got lost somehow.
Thanks for the advise on using GenericUDF.
cheers
Søren
On 05/12/2012 11:10, Vivek Mishra wrote:
The way UDF works is, you need to tell your ObjectInspector about your
primitive or JavaTypes. So in your case even if value is null, you should be
able to assign it as a String or any other object. Then invocation to
evaluate() function should know about type of java object.
-Vivek
From: Vivek Mishra
Sent: 05 December 2012 15:36
To: user@hive.apache.org
Subject: RE: handling null argument in custom udf
Could you please look into and share your task log/attemptlog for complete
error trace or actual error behind this?
-Vivek
From: Søren [s...@syntonetic.com]
Sent: 04 December 2012 20:28
To: user@hive.apache.org
Subject: Re: handling null argument in custom udf
Thanks. Did you mean I should handle null in my udf or my serde?
I did try to check for null inside the code in my udf, but it fails even before
it gets called.
This is from when the udf fails:
Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Unable to execute
method public org.apache.hadoop.io.Text
com.company.hive.myfun.evaluate(java.lang.Object,java.lang.Object)
on objectcom.company.hive.myfun@1412332 of class com.company.hive.myfun with
arguments {0:java.lang.Object, null} of size 2
It looks like there is a null, or is this error message misleading?
On 04/12/2012 15:43, Edward Capriolo wrote:
There is no null argument. You should handle the null case in your code.
If (arga == null)
Or optionally you could use a generic udf but a regular one should handle what
you are doing.
On Tuesday, December 4, 2012, Søren
mailto:s...@syntonetic.com>> wrote:
Hi Hive community
I have a custom udf, say myfun, written in Java which I utilize like this
select myfun(col_a, col_b) from mytable where etc
col_b is a string type and sometimes it is null.
When that happens, my query crashes with
---
java.lang.RuntimeException: org.apache.hadoop.hive.ql.metadata.HiveException:
Hive Runtime Error while processing row
{"col_a":"val","col_b":null}
...
Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Unable to execute
method public org.apache.hadoop.io.Text
---
public final class myfun extends UDF {
public Text evaluate(final Text argA, final Text argB) {
I'm unsure how this should be fixed in a proper way. Is the framework looking
for an overload of evaluate that would comply with the null argument?
I need to say that the table is declared using my own json serde reading from
S3. I'm not processing nulls in my serde in any special way because Hive seems
to handle null in the right way when not passed to my own UDF.
Are there anyone out there with ideas or experiences on this issue?
thanks in advance
Søren
NOTE: This message may contain information that is confidential, proprietary,
privileged or otherwise protected by law. The message is intended solely for
the named addressee. If received in error, please destroy and notify the
sender. Any use of this email is prohibited when received in error. Impetus
does not represent, warrant and/or guarantee, that the integrity of this
communication has been maintained nor that the communication is free of errors,
virus, interception or interference.
NOTE: This message may contain information that is confidential, proprietary,
privileged or otherwise protected by law. The message is intended solely for
the named addressee. If received in error, please destroy and notify the
sender. Any use of this email is prohibited when received in error. Impetus
does not represent, warrant and/or guarantee, that the integrity of this
communication has been maintained nor that the communication is free of errors,
virus, interception or interference.
Re: handling null argument in custom udf
Thanks. Did you mean I should handle null in my udf or my serde?
I did try to check for null inside the code in my udf, but it fails even
before it gets called.
This is from when the udf fails:
Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Unable to
execute method public org.apache.hadoop.io.Text
com.company.hive.myfun.evaluate(java.lang.Object,java.lang.Object)
on objectcom.company.hive.myfun@1412332 of class
com.company.hive.myfun with arguments {0:java.lang.Object, null} of size 2
It looks like there is a null, or is this error message misleading?
On 04/12/2012 15:43, Edward Capriolo wrote:
There is no null argument. You should handle the null case in your code.
If (arga == null)
Or optionally you could use a generic udf but a regular one should
handle what you are doing.
On Tuesday, December 4, 2012, Søren <mailto:s...@syntonetic.com>> wrote:
> Hi Hive community
>
> I have a custom udf, say myfun, written in Java which I utilize like
this
>
> select myfun(col_a, col_b) from mytable where etc
>
> col_b is a string type and sometimes it is null.
>
> When that happens, my query crashes with
> ---
> java.lang.RuntimeException:
org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error
while processing row
> {"col_a":"val","col_b":null}
> ...
> Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Unable
to execute method public org.apache.hadoop.io.Text
> ---
>
> public final class myfun extends UDF {
> public Text evaluate(final Text argA, final Text argB) {
>
> I'm unsure how this should be fixed in a proper way. Is the
framework looking for an overload of evaluate that would comply with
the null argument?
>
> I need to say that the table is declared using my own json serde
reading from S3. I'm not processing nulls in my serde in any special
way because Hive seems to handle null in the right way when not passed
to my own UDF.
>
> Are there anyone out there with ideas or experiences on this issue?
>
> thanks in advance
> Søren
>
>
handling null argument in custom udf
Hi Hive community
I have a custom udf, say myfun, written in Java which I utilize like this
select myfun(col_a, col_b) from mytable where etc
col_b is a string type and sometimes it is null.
When that happens, my query crashes with
---
java.lang.RuntimeException:
org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error
while processing row
{"col_a":"val","col_b":null}
...
Caused by: org.apache.hadoop.hive.ql.metadata.HiveException: Unable to
execute method public org.apache.hadoop.io.Text
---
public final class myfun extends UDF {
public Text evaluate(final Text argA, final Text argB) {
I'm unsure how this shouldbe fixed in a proper way.Is the framework
looking for an overload of evaluate that would comply with the null
argument?
I need to say that the table is declared using my own json serde reading
from S3. I'm not processing nulls in my serde in any special way because
Hive seems to handle null in the right way when not passed to my own UDF.
Are there anyone out there with ideas or experiences on this issue?
thanks in advance
Søren
external table on flume log files in S3
Hi Hive community We are collecting huge amounts of data into Amazon S3 using Flume. In Elastic Mapreduce, we have so far managed to create an external Hive table on JSON formatted gzipped log files in S3 using a customized serde. The log files are collected and stored in one single folder with file names following this pattern: usr-20120423-012725137+.2392780833002846.0029.gz usr-20120423-012928765+.2392904461259123.0029.gz usr-20120423-013032368+.2392968063991639.0029.gz There are thousands to millions of these files. Is there a way to make HIVE benefit from the datetime stamp in the filenames? For example to make queries on smaller subsets. Or filtering when creating the external table. If using the INPUT__FILE__NAME, the job gets done but there is no significant performance gain. I guess, due the the evaluation order of the SQL statement. I.e. processing the entire repository takes the same time as only one day's logs. Same large number of total open-file jobs. SELECT * FROM mytable WHERE INPUT__FILE__NAME LIKE 's3://myflume-logs/usr-20120423%'; Best practise knowledge from others who have been down this road is very welcomed. thanks in advance Soren
