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https://issues.apache.org/jira/browse/ACCUMULO-3602?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14499919#comment-14499919
]
ASF GitHub Bot commented on ACCUMULO-3602:
------------------------------------------
Github user echeipesh commented on a diff in the pull request:
https://github.com/apache/accumulo/pull/25#discussion_r28599303
--- Diff:
core/src/main/java/org/apache/accumulo/core/client/mapreduce/InputFormatBase.java
---
@@ -325,27 +362,12 @@ protected void setupIterators(TaskAttemptContext
context, Scanner scanner, Strin
* the Hadoop context for the configured job
* @param scanner
* the scanner to configure
+ * @deprecated since 1.7.0; Use {@link #contextIterators} instead.
*/
@Deprecated
protected void setupIterators(TaskAttemptContext context, Scanner
scanner) {
- setupIterators(context, scanner, null);
- }
-
- /**
- * Initialize a scanner over the given input split using this task
attempt configuration.
- */
- protected void setupIterators(TaskAttemptContext context, Scanner
scanner, org.apache.accumulo.core.client.mapreduce.RangeInputSplit split) {
--- End diff --
`setupIterators` with that sig became concrete in super type,
`AbstractInputFormat`
https://github.com/apache/accumulo/pull/25/files#diff-696314c306e81784094e2dc76341728bR479
I understood that would keep the compatability.
> BatchScanner optimization for AccumuloInputFormat
> -------------------------------------------------
>
> Key: ACCUMULO-3602
> URL: https://issues.apache.org/jira/browse/ACCUMULO-3602
> Project: Accumulo
> Issue Type: Improvement
> Components: client
> Affects Versions: 1.6.1, 1.6.2
> Reporter: Eugene Cheipesh
> Assignee: Eugene Cheipesh
> Labels: performance
> Fix For: 1.7.0
>
>
> Currently {{AccumuloInputFormat}} produces a split for reach {{Range}}
> specified in the configuration. Some table indexing schemes, for instance
> z-order geospacial index, produce large number of small ranges resulting in
> large number of splits. This is specifically a concern when using
> {{AccumuloInputFormat}} as a source for Spark RDD where each Split is mapped
> to an RDD partition.
> Large number of small RDD partitions leads to poor parallism on read and high
> overhead on processing. A desirable alternative is to group ranges by tablet
> into a single split and use {{BatchScanner}} to produce the records. Grouping
> by tablets is useful because it represents Accumulos attempt to distributed
> stored records and can be influance by the user through table splits.
> The grouping functionality already exists in the internal {{TabletLocator}}
> class.
> Current proposal is to modify {{AbstractInputFormat}} such that it generates
> either {{RangeInputSplit}} or {{MultiRangeInputSplit}} based on a new setting
> in {{InputConfigurator}}. {{AccumuloInputFormat}} would then be able to
> inspect the type of the split and instantiate an appropriate reader.
> The functinality of {{TabletLocator}} should be exposed as a public API in
> 1.7 as it is useful for optimizations.
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