Refers to reducers in the mapreduce framework. Mappers split up a large problem and solve parts of it in parallel. Reducers collect and summarize the output of a map method.
Reference: https://en.wikipedia.org/wiki/MapReduce
Questions tagged [reducers]
819 questions
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votes
1 answer
java.lang.Exception: java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be cast to org.apache.hadoop.io.IntWritable
public class PrimeMapper extends Mapper
{
public void map(LongWritable k,IntWritable val,Context c) throws IOException, InterruptedException
{
int…
AcCesS DoOmeR
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votes
1 answer
Hbase Error: java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be cast to org.apache.hadoop.hbase.client.Mutation
I am getting following error while transferring values from one Hbase table to other Hbase table. The code is working fine while transferring from Hbase table to file output.
Error: java.lang.ClassCastException: org.apache.hadoop.io.Text cannot be…
stonecrusher
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votes
3 answers
Array.length in map reduce throwing Null pointer exception
This is the code i am using in mapreduce and getting a null pointer exception..I am passing a variable via configuration, getting that as string and parsing and storing in an int array and processing that--
int[] results;
public void…
Muthu Palaniappan
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votes
1 answer
hadoop output file unrecognizable characters
I don't know how it happened, but suddenly my output file from my hadoop reducer contains a bunch of characters which I never put it in. The first few lines are…
King Saber
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1 answer
Can my reducer's output key type be different than input?
Actually my key to reducer is custom key (word1, word2) and I want to write output, in format like "word1\tword2" . And I'm not able to do that.
Any help appreciated.
Thanks.
EDIT: there was already \t between pair... I didn't notice it!
code muncher
- 1,592
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votes
3 answers
array of array sum and breaks when if-condition meet
I have a js array like this.
const test_arr = [ [ 20, 7, 23, 19, 10, 15, 25 ],
[ 20, 7, 23, 19, 10, 15, 8 ],
[ 20, 7, 23, 19, 10, 15, 13 ],
[ 20, 7, 23, 19, 10, 25, 8 ],
[ 20, 7, 23, 19, 10, 25, 13 ],
[ 20, 7, 23, 19, 10, 8, 13 ],
[ 20,…
horoyoi o
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votes
1 answer
Update to state does not get displayed in component in Redux
I update transcriptDisplay in reducer(I have a method on button click to update the state). I can see it getting updated in state tree.
case actions.TRANSCRIPT_GET:
return Object.assign({}, state, {
transcriptDisplay: action.payload,
…
funkadelic
- 83
- 10
-4
votes
1 answer
How to pass Badge Value with Redux to BottomTabBar on React Native
How to change Badge Value on BottomTabBar using Redux ?
Value Badge on BottomTabBar with Redux (99+) there i want to change it with value from redux
Connect
Rakha Hidayat
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votes
2 answers
How to delete state in every Reducer with single action
I have 10 reducer and I want to delete state values in every reducer with
a single click, how can I achieve this?
mustafa bagwala
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