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Small Avro Files

Small Avro Files

Champion Alumni



We have a  use case for ingesting binary files from mainframe to HDFS in avro format.These binary files contain  different record types that are variable in length .The first 4 bytes denotes the length of  the record.I have written a stand alone java program to  ingest the data  to hdfs using Avro DataFileWriter.Now these files from  mainframe are much smaller in size (under a block size) and creates small files .

Some of the   options we came up with  to avoid these are 


1. Convert the batch process to more   of a  service that runs behind the scene ,so the avro datafile writer can keep running and flush the data based on certain interval (time/size ) . I do not see a default implementation  for this  right now .

2. Write the data into an hdfs tmp location,merge the files   every hour or so and move the files to final hdfs destination. We can afford a latency of an hour before  data is made available to consumers.


3. Make use of avro append functionality.


Appreciate  your help!


Re: Small Avro Files

Super Collaborator

Why not compacting the historical data ... for example compact daily files into one file for now-14days.


A compaction job that runs daily and compact the data before 2 weeks.


By this you can make sure you are not imapcting the data freshness.