where is core-default.xml file?
It is in resources of hadoop-common
; https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/main/resources/core-default.xml
So in this case you will be able to find it inside jar file of hadoop-common
; the jar can be found in /opt/mapr/hadoop/hadoop-<version>/share/hadoop/common/hadoop-common-<version>.jar
I have extracted the jar and list the files;
[... ~]$ jar xf ./hadoop-common-<version>.jar
[... ~]$ ll
-rw-rw-r-- 1 mapr mapr 1041 Mar 15 18:36 common-version-info.properties
-rw-rw-r-- 1 mapr mapr 64287 Mar 15 18:06 core-default.xml
...
Is there any way to check the current value of parameter?
Yes there is. In order to grep the property by means of hadoop
utilities, please run the following command;
hadoop org.apache.hadoop.conf.Configuration | grep "fs.s3a.connection.ssl.enabled"