What can I do to monitor "out of shared memory" issues?

I'm new to database administration and I would really like some advice on what tools I could use or what I could do to monitor "out of shared memory" issues. I've been seeing these "out of shared memory" messages when I've been running *rspec* which runs tests for my application. I've also seen messages in the browser when I run my rails app that I "might need to increase max_locks_per_transaction." I think it would be better to find out exactly what is going on first either on the driver level or the PostgreSQL level. My specs are: PostgreSQL 9.4.5 on x86_64-apple-darwin15.0.0, compiled by Apple LLVM version 7.0.0 (clang-700.1.76), 64-bit I have a Macbook Pro running OSX El Capitan 10.11.5 I'm using the gem *pg* version 0.18.4 in my Ruby-on-Rails application.