Dong, We see this from time to time as well. In my experience, it is almost always caused by a bad node. You should try to find out where the file was written and remove that node as soon as possible.
As far as finding out what is wrong with the file, that's a difficult task. Parquet's encoding is very dense and corruption in encoded values often looks like different data. When you see a decoding exception like this, we find it is usually that the compressed data was corrupted and is no longer valid. You can look for the page of data based on the value counter, but that's about it. Even if you could find a single record that was affected, that's not valuable because you don't know whether there is other corruption that is undetectable. There's nothing to reliably recover here. What we do in this case is find and remove the bad node, then reprocess data so we know everything is correct from the upstream source. rb On Mon, Feb 5, 2018 at 9:01 AM, Dong Jiang <dji...@dataxu.com> wrote: > Hi, > > We are running on Spark 2.2.1, generating parquet files, like the following > pseudo code > df.write.parquet(...) > We have recently noticed parquet file corruptions, when reading the parquet > in Spark or Presto, as the following: > > Caused by: org.apache.parquet.io.ParquetDecodingException: Can not read > value at 40870 in block 0 in file > file:/Users/djiang/part-00122-80f4886a-75ce-42fa-b78f- > 4af35426f434.c000.snappy.parquet > > Caused by: org.apache.parquet.io.ParquetDecodingException: could not read > page Page [bytes.size=1048594, valueCount=43663, uncompressedSize=1048594] > in col [incoming_aliases_array, list, element, key_value, value] BINARY > > It appears only one column in one of the rows in the file is corrupt, the > file has 111041 rows. > > My questions are > 1) How can I identify the corrupted row? > 2) What could cause the corruption? Spark issue or Parquet issue? > > Any help is greatly appreciated. > > Thanks, > > Dong > > > > -- > Sent from: http://apache-spark-developers-list.1001551.n3.nabble.com/ > > --------------------------------------------------------------------- > To unsubscribe e-mail: dev-unsubscr...@spark.apache.org > > -- Ryan Blue Software Engineer Netflix
