Database Reference
In-Depth Information
Learning about mongostat
This tool produces a brief summary of relevant statistics of the currently running Mon-
goDB instances, either the
mongod
or
mongos
instance.
The following screenshot illustrates the output of this tool:
The preceding screenshot shows you the number of queries, update, insert, and delete oper-
ations from the database every second.
The following bullet list gives you a brief description for each column:
•
insert
: This refers to the number of insert operations per second.
•
query
: This refers to the number of queries per second.
•
update
: This refers to the number of update operations per second.
•
delete
: This refers to the number of delete operations per second.
•
getmore
: This refers to the number of
getmore
operations (that is, the
it
com-
mand in mongo shell) per second.
•
command
: This refers to the number of executed commands since the last
mon-
gostat
call.
•
flushes
: This refers to the number of
fsync
operations at the time of the last
mongostat
execution. The
fsync
operation is a system call that flushes all
dirty in-memory pages to the disk.
•
mapped
: This refers to the total amount of data mapped in megabytes.
•
vsize
: This refers to the amount of virtual memory in megabytes used by the pro-
cess at the time of the last
mongostat
execution.
•
res
: This refers to the amount of resident memory in megabytes used by the pro-
cess at the time of the last
mongostat
execution.
•
locked
: This refers to the percentage of time in a global write lock.
