[jira] [Created] (HIVE-19435) Data lost when Incremental REPL LOAD with Drop partitioned table followed by create/insert non-partitioned table with same name.

["Sankar Hariappan (JIRA)" <ji...@apache.org>]

Sankar Hariappan created HIVE-19435:
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             Summary: Data lost when Incremental REPL LOAD with Drop partitioned table followed by create/insert non-partitioned table with same name.
                 Key: HIVE-19435
                 URL: https://issues.apache.org/jira/browse/HIVE-19435
             Project: Hive
          Issue Type: Bug
          Components: HiveServer2, repl
    Affects Versions: 3.0.0
            Reporter: Sankar Hariappan
            Assignee: Sankar Hariappan
             Fix For: 3.0.0, 3.1.0


Hive replication uses Hadoop distcp to copy files from primary to replica warehouse. If the HDFS block size is different across clusters, it cause file copy failures.
{code:java}
2018-04-09 14:32:06,690 ERROR [main] org.apache.hadoop.tools.mapred.CopyMapper: Failure in copying hdfs://chelsea/apps/hive/warehouse/tpch_flat_orc_1000.db/customer/000259_0 to hdfs://marilyn/apps/hive/warehouse/tpch_flat_orc_1000.db/customer/.hive-staging_hive_2018-04-09_14-30-45_723_7153496419225102220-2/-ext-10001/000259_0
java.io.IOException: File copy failed: hdfs://chelsea/apps/hive/warehouse/tpch_flat_orc_1000.db/customer/000259_0 --> hdfs://marilyn/apps/hive/warehouse/tpch_flat_orc_1000.db/customer/.hive-staging_hive_2018-04-09_14-30-45_723_7153496419225102220-2/-ext-10001/000259_0
 at org.apache.hadoop.tools.mapred.CopyMapper.copyFileWithRetry(CopyMapper.java:299)
 at org.apache.hadoop.tools.mapred.CopyMapper.map(CopyMapper.java:266)
 at org.apache.hadoop.tools.mapred.CopyMapper.map(CopyMapper.java:52)
 at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:146)
 at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:787)
 at org.apache.hadoop.mapred.MapTask.run(MapTask.java:341)
 at org.apache.hadoop.mapred.YarnChild$2.run(YarnChild.java:170)
 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:1869)
 at org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:164)
Caused by: java.io.IOException: Couldn't run retriable-command: Copying hdfs://chelsea/apps/hive/warehouse/tpch_flat_orc_1000.db/customer/000259_0 to hdfs://marilyn/apps/hive/warehouse/tpch_flat_orc_1000.db/customer/.hive-staging_hive_2018-04-09_14-30-45_723_7153496419225102220-2/-ext-10001/000259_0
 at org.apache.hadoop.tools.util.RetriableCommand.execute(RetriableCommand.java:101)
 at org.apache.hadoop.tools.mapred.CopyMapper.copyFileWithRetry(CopyMapper.java:296)
 ... 10 more
Caused by: java.io.IOException: Check-sum mismatch between hdfs://chelsea/apps/hive/warehouse/tpch_flat_orc_1000.db/customer/000259_0 and hdfs://marilyn/apps/hive/warehouse/tpch_flat_orc_1000.db/customer/.hive-staging_hive_2018-04-09_14-30-45_723_7153496419225102220-2/-ext-10001/.distcp.tmp.attempt_1522833620762_4416_m_000000_0. Source and target differ in block-size. Use -pb to preserve block-sizes during copy. Alternatively, skip checksum-checks altogether, using -skipCrc. (NOTE: By skipping checksums, one runs the risk of masking data-corruption during file-transfer.)
 at org.apache.hadoop.tools.mapred.RetriableFileCopyCommand.compareCheckSums(RetriableFileCopyCommand.java:212)
 at org.apache.hadoop.tools.mapred.RetriableFileCopyCommand.doCopy(RetriableFileCopyCommand.java:130)
 at org.apache.hadoop.tools.mapred.RetriableFileCopyCommand.doExecute(RetriableFileCopyCommand.java:99)
 at org.apache.hadoop.tools.util.RetriableCommand.execute(RetriableCommand.java:87)
 ... 11 more
{code}
Distcp failed as the CM path for the file doesn't point to source file system. So, it is needed to get the qualified cm root URI as part of files listed in dump.

Also, REPL LOAD returns success even if distcp jobs failed.

CopyUtils.doCopyRetry doesn't throw error if copy failed even after maximum attempts. 

So, need to perform 2 things.
 # If copy of multiple files fail for some reason, then retry with same set of files again but need to set CM path if original source file is missing or modified based on checksum. Let distcp to skip the properly copied files. FileUtil.copy will always overwrite the files.
 # If source path is moved to CM path, then delete the incorrectly copied files.
 # If copy fails for maximum attempt, then throw error.

 



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