metadata operations failing in in-memory configurations

[1490812549:504397][5153:0x7f81b57fa700]  t  WT_SESSION.alter: metadata 

unroll update file:wt to access_pattern_hint=none allocation_size=512

app_metadata= block_allocation=best block_compressor=

cache_resident=false checkpoint= checkpoint_lsn= checksum="uncompressed"

collator= columns= dictionary=0 encryption=(keyid= name=) format=btree

huffman_key= huffman_value=english id=1

ignore_in_memory_cache_size=false internal_item_max=0

internal_key_max=659 internal_key_truncate=true internal_page_max=32768

key_format=r key_gap=11 leaf_item_max=0 leaf_key_max=818

leaf_page_max=32768 leaf_value_max=0 log=(enabled=true)

memory_page_max=5MB os_cache_dirty_max=0 os_cache_max=0

prefix_compression=false prefix_compression_min=4

split_deepen_min_child=0 split_deepen_per_child=0 split_pct=54

value_format=u version=(major=1 minor=1): WT_CACHE_FULL: operation would

overflow cache