HADOOP-17869. `fs.s3a.connection.maximum` should be bigger than `fs.s3a.threads.max` (#3337).

The value of `fs.s3a.connection.maximum` has been increased to 96

Contributed by Dongjoon Hyun

hadoop-common-project/hadoop-common/src/main/resources/core-default.xml

@@ -1381,7 +1381,7 @@
 
 <property>
   <name>fs.s3a.connection.maximum</name>
-  <value>48</value>
+  <value>96</value>
   <description>Controls the maximum number of simultaneous connections to S3.
     This must be bigger than the value of fs.s3a.threads.max so as to stop
     threads being blocked waiting for new HTTPS connections.

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/Constants.java

@@ -147,7 +147,7 @@ public final class Constants {
 
   // number of simultaneous connections to s3
   public static final String MAXIMUM_CONNECTIONS = "fs.s3a.connection.maximum";
-  public static final int DEFAULT_MAXIMUM_CONNECTIONS = 48;
+  public static final int DEFAULT_MAXIMUM_CONNECTIONS = 96;
 
   // connect to s3 over ssl?
   public static final String SECURE_CONNECTIONS =