To do this we will have to find Riak's riak.conf file, which can be
found where your installation keeps its Riak configuration files
(e.g., /etc/riak/riak.conf.config). If you are running SmartOS it will be at /opt/local/etc/riak/riak.conf, and if you used Homebrew to install Riak on OSX it will be at /usr/local/Cellar/riak/**VERSION**/libexec/etc/riak.conf.
Open the riak.conf file in your favorite text editor and search for the storage_backend setting.
Change it from bitcask to leveldb (because only
LevelDB
supports secondary indexes, a feature that we'll use in our examples in this tutorial).
Save your riak.conf and restart riak via the command line:
$ riak stop
$ riak start
Let's make sure the node is up and running:
$ riak ping