From 9edd88782e0268439c5ab57400d6a7ab432fc269 Mon Sep 17 00:00:00 2001
From: Chen Chao <crazyjvm@gmail.com>
Date: Wed, 16 Apr 2014 09:14:18 -0700
Subject: [PATCH] update spark.default.parallelism
actually, the value 8 is only valid in mesos fine-grained mode :
<code>
override def defaultParallelism() = sc.conf.getInt("spark.default.parallelism", 8)
</code>
while in coarse-grained model including mesos coares-grained, the value of the property depending on core numbers!
<code>
override def defaultParallelism(): Int = {
conf.getInt("spark.default.parallelism", math.max(totalCoreCount.get(), 2))
}
</code>
Author: Chen Chao <crazyjvm@gmail.com>
Closes #389 from CrazyJvm/patch-2 and squashes the following commits:
84a7fe4 [Chen Chao] miss </li> at the end of every single line
04a9796 [Chen Chao] change format
ee0fae0 [Chen Chao] update spark.default.parallelism
---
docs/configuration.md | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/docs/configuration.md b/docs/configuration.md
index f3bfd036f4..a3029837ff 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -96,7 +96,13 @@ Apart from these, the following properties are also available, and may be useful
<tr><th>Property Name</th><th>Default</th><th>Meaning</th></tr>
<tr>
<td>spark.default.parallelism</td>
- <td>8</td>
+ <td>
+ <ul>
+ <li>Mesos fine grained mode: 8</li>
+ <li>Local mode: core number of the local machine</li>
+ <li>Others: total core number of all executor nodes or 2, whichever is larger</li>
+ </ul>
+ </td>
<td>
Default number of tasks to use across the cluster for distributed shuffle operations (<code>groupByKey</code>,
<code>reduceByKey</code>, etc) when not set by user.
--
GitLab