Choose an installation path. In the following example, the libs will actually be installed at /usr/local/lib; note that lib is appended to the prefix.

export RDK_PREFIX=/usr/local

Download, build, and install.

wget https://github.com/edenhill/librdkafka/archive/v0.9.4.tar.gz  -O - | tar -xz
cd librdkafka-0.9.4/
./configure --prefix=$RDK_PREFIX
make 
make install

Ensure that the installation location is on the search path for the runtime shared library loader.

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$RDK_PREFIX/lib