Major Description
The LIRS cache calculates the estimated number of cells using the cache size and the average entry size, and allocates empty arrays accordingly.
Currently, the LIRS cache uses a default entry size of 100 bytes, which is relatively low. Because of that, even an empty cache needs quite a lot of memory.
I found the average size of the entries is around 2000 for our unit tests. Using this average size should reduce memory usage a lot.