Mongo Db Moitoring with mongotop Command

Mongo Db monitoring with mongotop command

mongotop provides a method to track the amount of time a MongoDB instance spends reading and writing data. mongotop provides statistics on a per-collection level. By default, mongotop returns values every second.

Mongotop  Options

--help, -h |Returns information on the options and use of mongotop.

--verbose, -v |Increases the amount of internal reporting returned on standard output or in log files. Increase the verbosity with the -v form by including the option multiple times, (e.g. -vvvvv.)

--quiet |Runs the mongotop in a quiet mode that attempts to limit the amount of output. This option suppresses:

• output from database commands
• replication activity
• connection accepted events
• connection closed events

--version|Returns the mongotop release number.

Fields in mongotop

mongotop.ns -- Contains the database namespace, which combines the database name and collection.
mongotop.db -- Contains the name of the database. Refers to the global lock, rather than a specific database. This field does not appear unless you have invoked mongotop with the --locks option.

mongotop.total -- Provides the total amount of time that this mongod spent operating on this namespace.
mongotop.read -- Provides the amount of time that this mongod spent performing read operations on this namespace.
mongotop.write -- Provides the amount of time that this mongod spent performing write operations on this namespace.
mongotop.<timestamp> -- Provides a time stamp for the returned data.

Syntax :

By default mongotop connects to the MongoDB instance running on the localhost port 27017.However, mongotop can optionally connect to remote mongod instances. See the mongotop options for more information.

mongotop  --  mongotop will return every second.
mongotop 15 -- mongotop will return every 15 seconds.

Mongo Db monitoring with mongostat command

The mongostat utility provides a quick overview of the status of a currently running mongod or mongosinstance. mongostat is functionally similar to the UNIX/Linux file system utility vmstat, but provides data regarding mongod and mongos instances.

Mongostat Options

--help, -h  | Returns information on the options and use of mongostat.

--verbose, -v | Increases the amount of internal reporting returned on standard output or in log files. Increase the verbosity with the -v form by including the option multiple times, (e.g. -vvvvv.)

--discover | Discovers and reports on statistics from all members of a replica set or sharded cluster. When connected to any member of a replica set, --discover all non-hidden members of the replica set. When connected to a mongos, mongostat will return data from all shards in the cluster. If a replica set provides a shard in the sharded cluster, mongostat will report on non-hidden members of that replica set

.—all | Configures mongostat to return all optional fields.

<sleeptime> | The final argument is the length of time, in seconds, that mongostat waits in between calls. By defaultmongostat returns one call every second.mongostat returns values that reflect the operations over a 1 second period. For values of<sleeptime> greater than 1, mongostat averages data to reflect average operations per second.

--rowcount <number>, -n | Controls the number of rows to output. Use in conjunction with the sleeptime argument to control the duration of a mongostat operation.Unless --rowcount is specified, mongostat will return an infinite number of rows (e.g. value of 0.)

--noheaders | Disables the output of column or field names.

mongostat outputs the following fields:

inserts -- Number of objects inserted into the database per second. If followed by an asterisk (e.g. *), the datum refers to a replicated operation.
query  --  Number of query operations per second.
update  --  Number of update operations per second.
delete  --  Number of delete operations per second.
getmore  --  Number of get more (i.e. cursor batch) operations per second.
command  --  Number of commands per second. On slave and secondary systems, mongostat presents two values separated by a pipe character (e.g. |), in the form of local|replicated commands.
flushes  --  Number of fsync operations per second.
mapped  --  Total amount of data mapped in MB. This is the total data size at the time of the last mongostat call.
size  --  Amount of (virtual) memory in megabytes used by the process at the time of the last mongostat call.
res  --  Amount of (resident) memory in megabytes used by the process at the time of the last mongostat call.
faults  --  Number of page faults per second.
locked  --  The percent of time in a global write lock.
locked db  --  The percent of time in the per-database context-specific lock. mongostat will report the database that has spent the most time since the last mongostat call with a write lock.
(This value represents the amount of time that the listed database spent in a locked state combined with the time that the mongod spent in the global lock. Because of this, and the sampling method, you may see some values greater than 100%.)
idx miss  --  The percent of index access attempts that required a page fault to load a btree node.
qr  --  The length of the queue of clients waiting to read data from the MongoDB instance.
qw  --  The length of the queue of clients waiting to write data from the MongoDB instance.
ar  --  The number of active clients performing read operations.
aw  --  The number of active clients performing write operations.
netIn  --  The amount of network traffic, in bytes, received by the MongoDB instance.
                (This includes traffic from mongostat itself.)
netOut  --  The amount of network traffic, in bytes, sent by the MongoDB instance.
                   (This includes traffic from mongostat itself.)
conn  --  The total number of open connections.
set  --  The name, if applicable, of the replica set.
repl  --  The replication status of the node.
                Value          Replication Type
                     M            master
                  SEC           secondary
                  REC           recovering
                 UNK          unknown
                  SLV           slave

Syntax :

mongostat --rowcount 20 1

mongostat --rowcount 20

mongostat -n 20 1

mongostat -n 20