[GitHub] spark pull request #15673: [SPARK-17992][SQL] Return all partitions from Hiv...

[mallman <gi...@git.apache.org>]

Github user mallman commented on a diff in the pull request:

    https://github.com/apache/spark/pull/15673#discussion_r216037341
  
    --- Diff: sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveShim.scala ---
    @@ -586,17 +587,31 @@ private[client] class Shim_v0_13 extends Shim_v0_12 {
             getAllPartitionsMethod.invoke(hive, table).asInstanceOf[JSet[Partition]]
           } else {
             logDebug(s"Hive metastore filter is '$filter'.")
    +        val tryDirectSqlConfVar = HiveConf.ConfVars.METASTORE_TRY_DIRECT_SQL
    +        val tryDirectSql =
    +          hive.getConf.getBoolean(tryDirectSqlConfVar.varname, tryDirectSqlConfVar.defaultBoolVal)
             try {
    +          // Hive may throw an exception when calling this method in some circumstances, such as
    +          // when filtering on a non-string partition column when the hive config key
    +          // hive.metastore.try.direct.sql is false
               getPartitionsByFilterMethod.invoke(hive, table, filter)
                 .asInstanceOf[JArrayList[Partition]]
             } catch {
    -          case e: InvocationTargetException =>
    -            // SPARK-18167 retry to investigate the flaky test. This should be reverted before
    -            // the release is cut.
    -            val retry = Try(getPartitionsByFilterMethod.invoke(hive, table, filter))
    -            logError("getPartitionsByFilter failed, retry success = " + retry.isSuccess)
    -            logError("all partitions: " + getAllPartitions(hive, table))
    -            throw e
    +          case ex: InvocationTargetException if ex.getCause.isInstanceOf[MetaException] &&
    +              !tryDirectSql =>
    +            logWarning("Caught Hive MetaException attempting to get partition metadata by " +
    +              "filter from Hive. Falling back to fetching all partition metadata, which will " +
    +              "degrade performance. Modifying your Hive metastore configuration to set " +
    +              s"${tryDirectSqlConfVar.varname} to true may resolve this problem.", ex)
    +            // HiveShim clients are expected to handle a superset of the requested partitions
    +            getAllPartitionsMethod.invoke(hive, table).asInstanceOf[JSet[Partition]]
    +          case ex: InvocationTargetException if ex.getCause.isInstanceOf[MetaException] &&
    +              tryDirectSql =>
    +            throw new RuntimeException("Caught Hive MetaException attempting to get partition " +
    --- End diff --
    
    Hi @rezasafi
    
    I believe the reasoning is if the user has disabled direct sql, we will try to fetch the partitions for the requested partition predicate anyway. However, since we don't expect that call to succeed, we just log a warning and fallback to the legacy behavior.
    
    On the other hand, if the user has enabled direct sql, then we expect the call to Hive to succeed. If it fails, we consider that an error and throw an exception.
    
    I hope that helps clarify things.


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