Support Questions
Find answers, ask questions, and share your expertise
Announcements
Alert: Welcome to the Unified Cloudera Community. Former HCC members be sure to read and learn how to activate your account here.

How to make hive queries including scala and python functions?

Solved Go to solution
Highlighted

How to make hive queries including scala and python functions?

Contributor

Hello guys,

I'm following this Twitter streaming spark tutorial

However, instead of Spark I'm using Flume and Hive to store the data.

The problem is that in the tutorial we create 2 functions: one in scala and the other in python.

And when I use the hive interpreter to access the data %hive it doens't recognize the functions created before.

Is there any way to make a bridge between Scala and/or Python so that Hive can recognize these 2 functions?

/* declaring a function in Scala */

def sentiment(s:String) : String = {
    val positive = Array("like", "love", "good", "great", "happy", "cool", "the", "one", "that")
    val negative = Array("hate", "bad", "stupid", "is")

    var st = 0;

    val words = s.split(" ")    
    positive.foreach(p =>
        words.foreach(w =>
            if(p==w) st = st+1
        )
    )

    negative.foreach(p=>
        words.foreach(w=>
            if(p==w) st = st-1
        )
    )
    if(st>0)
        "positivie"
    else if(st<0)
        "negative"
    else
        "neutral"
}

sqlc.udf.register("sentiment", sentiment _)
%pyspark

#declaring a function in Python

import re

def wordcount(a):
  return len(re.split("\W+",a))
  
sqlContext.registerFunction("wordcount", wordcount)

Many thanks in advance.

Best regards

1 ACCEPTED SOLUTION

Accepted Solutions
Highlighted

Re: How to make hive queries including scala and python functions?

@Hugo Felix

One option is to implement these functions as a Hive UDF (written in python).

For example, your new python function (my_py_udf.py) would look something like this:

import sys

for line in sys.stdin:
    
    createdAt, screenName, text = line.replace('\n',' ').split('\t')
    
    positive = set(["love", "good", "great", "happy", "cool", "best", "awesome", "nice"])
    negative = set(["hate", "bad", "stupid"])
    
    words = text.split()
    word_count = len(words)
    
    positive_matches = [1 for word in words if word in positive]
    negative_matches = [-1 for word in words if word in negative]
    
    st = sum(positive_matches) + sum(negative_matches)
    
    if st > 0:
        print '\t'.join([text, 'positive', str(word_count)])
    elif st < 0:
        print '\t'.join([text, 'negative', str(word_count)])
    else:
        print '\t'.join([text, 'neutral', str(word_count)])

NOTE: This function combines both of your previous functions into one (since you can calculate wordcount and sentiment in one function).

To call this UDF within Hive, run Hive code similar to this:

ADD FILE /home/hive/my_py_udf.py;
SELECT
TRANSFORM (createdAt, screenName, text)
USING 'python my_py_udf.py'
AS  text, 
    sentiment,
    word_count
FROM tweets;

Hope this helps!

View solution in original post

23 REPLIES 23
Highlighted

Re: How to make hive queries including scala and python functions?

@Hugo Felix

One option is to implement these functions as a Hive UDF (written in python).

For example, your new python function (my_py_udf.py) would look something like this:

import sys

for line in sys.stdin:
    
    createdAt, screenName, text = line.replace('\n',' ').split('\t')
    
    positive = set(["love", "good", "great", "happy", "cool", "best", "awesome", "nice"])
    negative = set(["hate", "bad", "stupid"])
    
    words = text.split()
    word_count = len(words)
    
    positive_matches = [1 for word in words if word in positive]
    negative_matches = [-1 for word in words if word in negative]
    
    st = sum(positive_matches) + sum(negative_matches)
    
    if st > 0:
        print '\t'.join([text, 'positive', str(word_count)])
    elif st < 0:
        print '\t'.join([text, 'negative', str(word_count)])
    else:
        print '\t'.join([text, 'neutral', str(word_count)])

NOTE: This function combines both of your previous functions into one (since you can calculate wordcount and sentiment in one function).

To call this UDF within Hive, run Hive code similar to this:

ADD FILE /home/hive/my_py_udf.py;
SELECT
TRANSFORM (createdAt, screenName, text)
USING 'python my_py_udf.py'
AS  text, 
    sentiment,
    word_count
FROM tweets;

Hope this helps!

View solution in original post

Highlighted

Re: How to make hive queries including scala and python functions?

Contributor

@Dan Zaratsian

Many many thanks for your great answer!

I ran the code you gave me but encounter a first error which was due to the fact that I had security enabled on hive. Disabled it and now I get this one:

java.sql.SQLException: Error while 
processing statement: FAILED: Execution Error, return code 2 from 
org.apache.hadoop.hive.ql.exec.tez.TezTask. Vertex failed, 
vertexName=Map 1, vertexId=vertex_1499773736316_0013_1_00, 
diagnostics=[Task failed, taskId=task_1499773736316_0013_1_00_000000, 
diagnostics=[TaskAttempt 0 failed, info=[Error: Failure while running 
task:java.lang.RuntimeException: java.lang.RuntimeException: 
org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error 
while processing row {"id":884722952981426178,"created_at":"Tue Jul 11 
10:36:04 +0000 2017","source":"<a 
href=\"http://twitter.com/download/iphone\" rel=\"nofollow\">Twitter 
for 
iPhone</a>","favorited":false,"retweeted_status":{"text":"We're 
hiring! https://t.co/jGOOgyxuzo via @colliderocks #jobs #onsite #lisbon 
#gamedev","user":{"screen_name":"tiagomploureiro","name":"Tiago 
Loureiro"},"retweet_count":1},"entities":{"urls":[{"expanded_url":"https://collide.rocks/careers/"}],"user_mentions":[{"screen_name":"tiagomploureiro","name":"Tiago
 
Loureiro"},{"screen_name":"CollideRocks","name":"Collide"}],"hashtags":[{"text":"jobs"},{"text":"onsite"},{"text":"lisbon"},{"text":"gamedev"}]},"lang":"en","retweet_count":0,"text":"RT
 @tiagomploureiro: We're hiring! https://t.co/jGOOgyxuzo via 
@colliderocks #jobs #onsite #lisbon 
#gamedev","user":{"screen_name":"diogostuart","name":"Diogo 
Vasconcelos","friends_count":1976,"followers_count":2954,"statuses_count":5122,"verified":false,"utc_offset":3600,"time_zone":"Lisbon"},"datehour":2017071111}
	at 
org.apache.hadoop.hive.ql.exec.tez.TezProcessor.initializeAndRunProcessor(TezProcessor.java:173)
	at 
org.apache.hadoop.hive.ql.exec.tez.TezProcessor.run(TezProcessor.java:139)
	at 
org.apache.tez.runtime.LogicalIOProcessorRuntimeTask.run(LogicalIOProcessorRuntimeTask.java:344)
	at 
org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable$1.run(TezTaskRunner.java:181)
	at 
org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable$1.run(TezTaskRunner.java:172)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:422)
	at 
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
	at 
org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable.callInternal(TezTaskRunner.java:172)
	at 
org.apache.tez.runtime.task.TezTaskRunner$TaskRunnerCallable.callInternal(TezTaskRunner.java:168)
	at org.apache.tez.common.CallableWithNdc.call(CallableWithNdc.java:36)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at 
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.RuntimeException: 
org.apache.hadoop.hive.ql.metadata.HiveException: Hive Runtime Error 
while processing row {"id":884722952981426178,"created_at":"Tue Jul 11 
10:36:04 +0000 2017","source":"<a 
href=\"http://twitter.com/download/iphone\" rel=\"nofollow\">Twitter 
for 
iPhone</a>","favorited":false,"retweeted_status":{"text":"We're 
hiring! https://t.co/jGOOgyxuzo via @colliderocks #jobs #onsite #lisbon 
#gamedev","user":{"screen_name":"tiagomploureiro","name":"Tiago 
Loureiro"},"retweet_count":1},"entities":{"urls":[{"expanded_url":"https://collide.rocks/careers/"}],"user_mentions":[{"screen_name":"tiagomploureiro","name":"Tiago
 
Loureiro"},{"screen_name":"CollideRocks","name":"Collide"}],"hashtags":[{"text":"jobs"},{"text":"onsite"},{"text":"lisbon"},{"text":"gamedev"}]},"lang":"en","retweet_count":0,"text":"RT
 @tiagomploureiro: We're hiring! https://t.co/jGOOgyxuzo via 
@colliderocks #jobs #onsite #lisbon 
#gamedev","user":{"screen_name":"diogostuart","name":"Diogo 
Vasconcelos","friends_count":1976,"followers_count":2954,"statuses_count":5122,"verified":false,"utc_offset":3600,"time_zone":"Lisbon"},"datehour":2017071111}
	at 
org.apache.hadoop.hive.ql.exec.tez.MapRecordSource.processRow(MapRecordSource.java:91)
	at 
org.apache.hadoop.hive.ql.exec.tez.MapRecordSource.pushRecord(MapRecordSource.java:68)
	at 
(...)



I think this is an out o memory error... What do you think?

I've always had a lot of difficulties configuring the memory on this VM.

Many thanks in advance. Kind regards

Highlighted

Re: How to make hive queries including scala and python functions?

@Hugo Felix

It might be an out of memory issue, but it could also be a variable/column mismatch. Can you share your python function and the Hive query so that I can review?

Highlighted

Re: How to make hive queries including scala and python functions?

Contributor

@Dan Zaratsian

I'm using the stuff you've gave me for now:

    import sys
     
    for line in sys.stdin:
        
        created_at, user.screen_name, text = line.split('\t')
        
        positive = set(["love", "good", "great", "happy", "cool", "best", "awesome", "nice"])
        negative = set(["hate", "bad", "stupid"])
        
        words = text.split()
        word_count = len(words)
        
        positive_matches = [1 for word in words if word in positive]
        negative_matches = [-1 for word in words if word in negative]
        
        st = sum(positive_matches) + sum(negative_matches)
        
        if st > 0:
            print '\t'.join([text, 'positive', str(word_count)])
        elif st < 0:
            print '\t'.join([text, 'negative', str(word_count)])
        else:
            print '\t'.join([text, 'neutral', str(word_count)])
ADD JAR /tmp/json-serde-1.3.8-jar-with-dependencies.jar;
ADD FILE /tmp/my_py_udf.py;

SELECT
    TRANSFORM (created_at, user.screen_name, text)
    USING 'python my_py_udf.py'
    AS  text, 
        sentiment,
        word_count
    FROM tweets
Highlighted

Re: How to make hive queries including scala and python functions?

Contributor

@Dan Zaratsian

Can you please help one more time?

Many thanks in advance.

Re: How to make hive queries including scala and python functions?

@Hugo Felix What happens if you replace

created_at, user.screen_name, text = line.split('\t')

with

created_at, screen_name, text = line.split('\t')

I do not believe python will be able to parse the user.screen_name variable in the context you are writing it. In my example, the function accepts a tab-delimited argument and then you perform the split('\t'), it parses the argument out into X number of variables. The names of the assigned variables (such as created_at, screen_name, text) are arbitrary (you could name then x,y,z if you wanted, but you would have to make sure the rest of the python script used the x,y,z variable names). Give that a try and let me know if it helps. Thanks.

Highlighted

Re: How to make hive queries including scala and python functions?

Contributor

Hello @Dan Zaratsian

It happens exactly the same...

I'm still wondering if this is a problem of Hive or some other configuration on Ambari.

I ask this because I've made this simple UDF:

import sys
for line in sys.stdin:
print '\t'.join([line])

And ran this query:

ADD JAR /tmp/json-serde-1.3.8-jar-with-dependencies.jar;
ADD FILE /tmp/test.py;

SELECT
    TRANSFORM (text)
    USING 'python test.py'
    FROM tweets

And I'm getting the exact same error...

Highlighted

Re: How to make hive queries including scala and python functions?

@Hugo Felix Yeah, that was the next test I had in mind for you to test out. Thanks for sharing the results. Can you share the environment you are working in?

Are you using Spark 1.6.x or Spark 2.x?

Also, what version of HDP are you using?

Highlighted

Re: How to make hive queries including scala and python functions?

Contributor

@Dan Zaratsian

I'm not using Spark at the moment since I'm running the job directly on Hive for troubleshooting

Spark ver - 1.6.x.2.4

Hive - 1.2.1.2.4

HDP - 2.4.0.0

Don't have an account?
Coming from Hortonworks? Activate your account here