For diagnostic purposes, it's useful to print out statistics of the objects in the CDS archive heap. For example, this shows the number of objects with a distribution of different sizes.

[6.772s][info][cds,heap] 0 objects are <= 8 bytes (total 0 bytes, avg 0.0 bytes)
[6.772s][info][cds,heap] 1205 objects are <= 16 bytes (total 19280 bytes, avg 16.0 bytes)
[6.772s][info][cds,heap] 15717 objects are <= 32 bytes (total 411024 bytes, avg 26.2 bytes)
[6.772s][info][cds,heap] 4127 objects are <= 64 bytes (total 198080 bytes, avg 48.0 bytes)
[6.772s][info][cds,heap] 2380 objects are <= 128 bytes (total 243016 bytes, avg 102.1 bytes)
[6.772s][info][cds,heap] 293 objects are <= 256 bytes (total 47920 bytes, avg 163.5 bytes)
[6.772s][info][cds,heap] 51 objects are <= 512 bytes (total 17112 bytes, avg 335.5 bytes)
[6.772s][info][cds,heap] 18 objects are <= 1024 bytes (total 14480 bytes, avg 804.4 bytes)
[6.772s][info][cds,heap] 11 objects are <= 2048 bytes (total 13440 bytes, avg 1221.8 bytes)
[6.772s][info][cds,heap] 3 objects are <= 4096 bytes (total 9808 bytes, avg 3269.3 bytes)
[6.772s][info][cds,heap] 3 objects are <= 8192 bytes (total 12840 bytes, avg 4280.0 bytes)
[6.772s][info][cds,heap] 4 objects are <= 16384 bytes (total 37240 bytes, avg 9310.0 bytes)
[6.772s][info][cds,heap] 0 objects are <= 32768 bytes (total 0 bytes, avg 0.0 bytes)
[6.772s][info][cds,heap] 0 objects are <= 65536 bytes (total 0 bytes, avg 0.0 bytes)
[6.772s][info][cds,heap] 0 objects are <= 131072 bytes (total 0 bytes, avg 0.0 bytes)
[6.772s][info][cds,heap] 0 objects are <= 262144 bytes (total 0 bytes, avg 0.0 bytes)
[6.772s][info][cds,heap] 0 huge objects (total 0 bytes, avg 0.0 bytes)
[6.772s][info][cds,heap] 23812 total objects (total 1024240 bytes, avg 43.0 bytes)