[Backport] Add doc for Hadoop-based ingestion vs Native batch ingestion

docs/content/ingestion/hadoop-vs-native-batch.md

@@ -0,0 +1,43 @@
+---
+layout: doc_page
+title: "Hadoop-based Batch Ingestion VS Native Batch Ingestion"
+---
+
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+
+# Comparison of Batch Ingestion Methods
+
+Druid basically supports three types of batch ingestion: Hadoop-based
+batch ingestion, native parallel batch ingestion, and native local batch
+ingestion. The below table shows what features are supported by each
+ingestion method.
+
+
+|   |Hadoop-based ingestion|Native parallel ingestion|Native local ingestion|
+|---|----------------------|-------------------------|----------------------|
+| Parallel indexing | Always parallel | Parallel if firehose is splittable | Always sequential |
+| Supported indexing modes | Replacing mode | Both appending and replacing modes | Both appending and replacing modes |
+| External dependency | Hadoop (it internally submits Hadoop jobs) | No dependency | No dependency |
+| Supported [rollup modes](http://druid.io/docs/latest/ingestion/index.html#roll-up-modes) | Perfect rollup | Best-effort rollup | Both perfect and best-effort rollup |
+| Supported partitioning methods | [Both Hash-based and range partitioning](http://druid.io/docs/latest/ingestion/hadoop.html#partitioning-specification) | N/A | Hash-based partitioning (when `forceGuaranteedRollup` = true) |
+| Supported input locations | All locations accessible via HDFS client or Druid dataSource | All implemented [firehoses](./firehose.html) | All implemented [firehoses](./firehose.html) |
+| Supported file formats | All implemented Hadoop InputFormats | Currently only text file format (CSV, TSV, JSON) | Currently only text file format (CSV, TSV, JSON) |
+| Saving parse exceptions in ingestion report | Currently not supported | Currently not supported | Supported |
+| Custom segment version | Supported, but this is NOT recommended | N/A | N/A |

docs/content/ingestion/hadoop.md

@@ -25,7 +25,9 @@ title: "Hadoop-based Batch Ingestion"
 # Hadoop-based Batch Ingestion
 
 Hadoop-based batch ingestion in Druid is supported via a Hadoop-ingestion task. These tasks can be posted to a running
-instance of a Druid [Overlord](../design/overlord.html). 
+instance of a Druid [Overlord](../design/overlord.html).
+
+Please check [Hadoop-based Batch Ingestion VS Native Batch Ingestion](./hadoop-vs-native-batch.html) for differences between native batch ingestion and Hadoop-based ingestion.
 
 ## Command Line Hadoop Indexer
 

docs/content/ingestion/native_tasks.md

@@ -28,6 +28,8 @@ Druid currently has two types of native batch indexing tasks, `index_parallel` w
 in parallel on multiple MiddleManager nodes, and `index` which will run a single indexing task locally on a single
 MiddleManager.
 
+Please check [Hadoop-based Batch Ingestion VS Native Batch Ingestion](./hadoop-vs-native-batch.html) for differences between native batch ingestion and Hadoop-based ingestion.
+
 Parallel Index Task
 --------------------------------
 

docs/content/ingestion/tasks.md

@@ -41,6 +41,10 @@ See [batch ingestion](../ingestion/hadoop.html).
 Druid provides a native index task which doesn't need any dependencies on other systems.
 See [native index tasks](./native_tasks.html) for more details.
 
+<div class="note info">
+Please check [Hadoop-based Batch Ingestion VS Native Batch Ingestion](./hadoop-vs-native-batch.html) for differences between native batch ingestion and Hadoop-based ingestion.
+</div>
+
 ### Kafka Indexing Tasks
 
 Kafka Indexing tasks are automatically created by a Kafka Supervisor and are responsible for pulling data from Kafka streams. These tasks are not meant to be created/submitted directly by users. See [Kafka Indexing Service](../development/extensions-core/kafka-ingestion.html) for more details.