NAME

       mongoperf - MongoDB

SYNOPSIS

       mongoperf is a utility to check disk I/O performance independently of MongoDB.

       It  times tests of random disk I/O and presents the results. You can use mongoperf for any
       case apart from MongoDB. The mmf true mode is completely  generic.  In  that  mode  is  it
       somewhat analogous to tools such as bonnie++ (albeit mongoperf is simpler).

       Specify options to mongoperf using a JavaScript document.

       See also

       • bonnie

       • bonnie++

       • Output from an example run

       • Checking Disk Performance with the mongoperf Utility

OPTIONS

       mongoperf

       --help Displays  the  options  to  mongoperf.   Specify  options  to mongoperf with a JSON
              document described in the Configuration Fields section.

       <jsonconfig>
              mongoperf accepts configuration options in the form of a file  that  holds  a  JSON
              document.  You  must  stream  the  content  of  this file into mongoperf, as in the
              following operation:

              mongoperf < config

              In this example config is the name of a  file  that  holds  a  JSON  document  that
              resembles the following example:

              {
                nThreads:<n>,
                fileSizeMB:<n>,
                sleepMicros:<n>,
                mmf:<bool>,
                r:<bool>,
                w:<bool>,
                recSizeKB:<n>,
                syncDelay:<n>
              }

              See the Configuration Fields section for documentation of each of these fields.

CONFIGURATION FIELDS

       mongoperf.nThreads
              Type: Integer.

              Default: 1

              Defines  the  number  of  threads  mongoperf will use in the test. To saturate your
              system's storage system you will need multiple threads. Consider  setting  nThreads
              to 16.

       mongoperf.fileSizeMB
              Type: Integer.

              Default: 1 megabyte (i.e. 10242 bytes)

              Test file size.

       mongoperf.sleepMicros
              Type: Integer.

              Default: 0

              mongoperf  will  pause  for  the  number  of  specified  sleepMicros divided by the
              nThreads between each operation.

       mongoperf.mmf
              Type: Boolean.

              Default: false

              Set mmf to true to use memory mapped files for the tests.

              Generally:

              • when mmf is false, mongoperf tests direct, physical, I/O, without caching. Use  a
                large file size to test heavy random I/O load and to avoid I/O coalescing.

              • when  mmf is true, mongoperf runs tests of the caching system, and can use normal
                file system cache. Use mmf in this mode to test file system cache  behavior  with
                memory mapped files.

       mongoperf.r
              Type: Boolean.

              Default: false

              Set r to true to perform reads as part of the tests.

              Either r or w must be true.

       mongoperf.w
              Type: Boolean.

              Default: false

              Set w to true to perform writes as part of the tests.

              Either r or w must be true.

       mongoperf.syncDelay
              Type: Integer.

              Default: 0

              Seconds between disk flushes. syncDelay is similar to syncDelay for mongod.

              The syncDelay controls how frequently mongoperf performs an asynchronous disk flush
              the memory mapped file used for testing. By default, mongod performs this operation
              every every 60 seconds. Use syncDelay to test basic system performance of this type
              of operation.

              Only use syncDelay in conjunction with mmf set to true.

              The default value of 0 disables this

USE

       mongoperf < jsonconfigfile

       Replace jsonconfigfile with the path to the mongoperf configuration. You may  also  invoke
       mongoperf in the following form:

       echo "{nThreads:16,fileSizeMB:1000,r:true}" | ./mongoperf

       In this operation:

       • mongoperf tests direct physical random read io's, using 16 concurrent reader threads.

       • mongoperf  uses a 1 gigabyte test file.

       Consider  using  iostat,  as  invoked  in the following example to monitor I/O performance
       during the test.

       iostat -xm 2

AUTHOR

       MongoDB Documentation Project

COPYRIGHT

       2011-2013, 10gen, Inc.