The cbstats memory command gets memory-related statistics.

CLI command and parameter

This provides various memory-related stats including the stats from tcmalloc.

cbstats all
Note: tcmalloc stats are not available on operating systems (e.g., Windows) that do not support tcmalloc.
Stat Description
mem_used (deprecated) Engine’s total memory usage
bytes Engine’s total memory usage
ep_kv_size Memory used to store item metadata,
keys and values, no matter the
vbucket’s state. If an item’s value
is ejected, this stat will be
decremented by the size of the
item’s value.
ep_value_size Memory used to store values for
resident keys
ep_overhead Extra memory used by transient data
like persistence queue, replication
queues, checkpoints, etc
ep_max_size Max amount of data allowed in memory
ep_mem_low_wat Low water mark for auto-evictions
ep_mem_high_wat High water mark for auto-evictions
ep_oom_errors Number of times unrecoverable OOMs
happened while processing operations
ep_tmp_oom_errors Number of times temporary OOMs
happened while processing operations
ep_mem_tracker_enabled If smart memory tracking is enabled
tcmalloc_allocated_bytes Engine’s total memory usage reported
from tcmalloc
tcmalloc_heap_size Bytes of system memory reserved by
tcmalloc_free_bytes Number of bytes in free, mapped
pages in page heap
tcmalloc_unmapped_bytes Number of bytes in free, unmapped
pages in page heap. These are bytes
that have been released back to OS
tcmalloc_max_thread_cache_bytes A limit to how much memory TCMalloc
dedicates for small objects
tcmalloc_current_thread_cache_bytes A measure of some of the memory
TCMalloc is using for small objects


Request syntax:

cbstats [localhost]:11210 memory


Example request:

cbstats memory


Example response:

bytes:                               23716184
 ep_blob_num:                         0
 ep_blob_overhead:                    0
 ep_item_num:                         1364
 ep_kv_size:                          0
 ep_max_size:                         524288000
 ep_mem_high_wat:                     445644800
 ep_mem_low_wat:                      393216000
 ep_mem_tracker_enabled:              true
 ep_oom_errors:                       0
 ep_overhead:                         18344996
 ep_storedval_num:                    0
 ep_storedval_overhead:               0
 ep_storedval_size:                   0
 ep_tmp_oom_errors:                   0
 ep_value_size:                       0
 mem_used:                            23716184
 tcmalloc_current_thread_cache_bytes: 18642072
 tcmalloc_max_thread_cache_bytes:     33554432
 total_allocated_bytes:               211297528
 total_fragmentation_bytes:           33069832
 total_free_mapped_bytes:             5283840
 total_free_unmapped_bytes:           7684096
 total_heap_bytes:                    257335296