It's not mapred.tasttracker.map.tasks.maximum
, but mapred.tasktracker.map.tasks.maximum
. I hope it is only a typo and you used correct names in your config.
On startup DSE creates dse-mapred-default.xml and dse-core-default.xml files and fills them with defaults adapted to your local OS configuration and hardware. This is mostly for Hadoop autotuning feature and for simplifying configuring of security-enabled Hadoop. Then Hadoop loads config files in the following order:
- Hadoop internal defaults (the defaults you can find in the Hadoop docs)
- DSE defaults from dse-core-default.xml and dse-mapred-default.xml
- User files: core-site.xml and mapred-site.xml.
Settings from files loaded later override settings loaded earlier. The final state of configuration is not written back to the files with defaults. You should not expect settings from mapred-site.xml to be copied into dse-mapred-default.xml files.
If you're unsure what is the final configuration and whether your settings are properly set - just run a job and look into hadoop log directory and search for files matching pattern job_xxxxxxxxxxxx_xxxx_conf.xml, where x is a digit. You can also view the final config in the jobtracker HTTP console.