As Titan is required throughout this chapter, I will install it now, and show how it can be acquired, installed, and configured. I have downloaded the latest prebuilt version (0.9.0-M2) of Titan at: s3.thinkaurelius.com/downloads/titan/titan-0.9.0-M2-hadoop1.zip.

I have downloaded the zipped release to a temporary directory, as shown next. Carry out the following steps to ensure that Titan is installed on each node in the cluster:

[[hadoop@hc2nn tmp]$ ls -lh titan-0.9.0-M2-hadoop1.zip
-rw-r--r-- 1 hadoop hadoop 153M Jul 22 15:13 titan-0.9.0-M2-hadoop1.zip

Using the Linux unzip command, unpack the zipped Titan release file:

[hadoop@hc2nn tmp]$ unzip titan-0.9.0-M2-hadoop1.zip

[hadoop@hc2nn tmp]$ ls -l
total 155752
drwxr-xr-x 10 hadoop hadoop      4096 Jun  9 00:56 titan-0.9.0-M2-hadoop1
-rw-r--r--  1 hadoop hadoop 159482381 Jul 22 15:13 titan-0.9.0-M2-hadoop1.zip

Now, use the Linux su (switch user) command to change to the root account, and move the install to the /usr/local/ location. Change the file and group membership of the install to the hadoop user, and create a symbolic link called titan so that the current Titan release can be referred to as the simplified path called /usr/local/titan:

[hadoop@hc2nn ~]$ su –
[root@hc2nn ~]# cd /home/hadoop/tmp
[root@hc2nn titan]# mv titan-0.9.0-M2-hadoop1 /usr/local
[root@hc2nn titan]# cd /usr/local
[root@hc2nn local]# chown -R hadoop:hadoop titan-0.9.0-M2-hadoop1
[root@hc2nn local]# ln -s titan-0.9.0-M2-hadoop1 titan
[root@hc2nn local]# ls -ld *titan*
lrwxrwxrwx  1 root   root     19 Mar 13 14:10 titan -> titan-0.9.0-M2-hadoop1
drwxr-xr-x 10 hadoop hadoop 4096 Feb 14 13:30 titan-0.9.0-M2-hadoop1

Using a Titan Gremlin shell that will be demonstrated later, Titan is now available for use. This version of Titan needs Java 8; make sure that you have it installed.