According to redis docs, it's advisable to disable Transparent Huge Pages.
Would the guidance be the same if the machine was shared between the redis server and the application.
Moreover, for other technologies, I've also read guidance that THP should be disabled for all production environments when setting up the server. Is this kind of pre-emptiveness applicable to redis as well, or one must first strictly monitor latency issues before deciding to turn off THP?
Note: At the time this answer was originally written, turning off THP was still advised all the time. Things have changed since this and it is no longer advisable to turn off THP unless you are persisting to disk. I am only leaving this answer here for posterity's sake.
Turn it off. The problem lies in how THP shifts memory around to try and keep or create contiguous pages. Some applications can tolerate this, most databases cannot and it causes intermittent performance problems, some pretty bad. This is not unique to Redis by any means.
For your application, especially if it is JAVA, set up real HugePages and leave the transparent variety out of it. If you do that just make sure you allocate memory correctly for the app and redis. Though I have to say, I probably would not recommend running both the app and redis on the same instance/server/vm.