This benchRun command is designed as a QA baseline performance measurement tool; it is not designed to be a "benchmark".

db.foo.drop();
db.foo.insert( { _id : 1 } )

ops = [{op: "findOne", ns: "test.foo", query: {_id: 1}},
       {op: "update", ns: "test.foo", query: {_id: 1}, update: {$inc: {x: 1}}}]

for ( var x = 1; x <= 128; x *= 2) {
    res = benchRun( {
        parallel : x ,
        seconds : 5 ,
        ops : ops
    } );
    print( "threads: " + x + "\t queries/sec: " + res.query );
}

// benchmark updates using the $inc operator
res = benchRun( {
    ops : [ {
        ns : "test.foo" ,
        op : "update" ,
        query : { _id : { "#RAND_INT" : [ 0 , 100 ] } } ,
        update : { $inc : { x : 1 } }
    } ] ,
    parallel : 2 ,
    seconds : 1
} );
print( "threads: 2\t update/sec: " + res.update );
// benchmark inserts with random strings
res = benchRun( {
    ops : [ {
        ns : "test.foo" ,
        op : "insert" ,
        doc : { y : { "#RAND_STRING" : [ 10 ] } }
    } ] ,
    parallel : 2 ,
    seconds : 1
} );
print( "threads: 2\t insert/sec: " + res.insert );

• host

  The hostname of the machine mongod is running on (defaults to localhost).

• username

  The username to use when authenticating to mongod (only use if running with auth).

• password

  The password to use when authenticating to mongod (only use if running with auth).

• db

  The database to authenticate to (only necessary if running with auth).

• ops

  A list of objects describing the operations to run (documented below).

• parallel

  The number of threads to run (defaults to single thread).

• seconds

  The amount of time to run the tests for (defaults to one second).

• hideResults

  Prevents results from each operation executed from being logged. Default value is true. Overridden by setting showResult on a specific operation.

• handleErrors

  Prevents a thread from stopping on error. Default value is false. Overridden by setting handleError on a specific operation.

• hideErrors

  Prevents errors from being logged. Default value is false. Overridden by setting showError for a specific operation.

• throwGLE

  Causes benchRun to actually throw an exception on errors in updates/inserts/deletes rather than handling them. Default value is false to have benchRun to handle the errors itself. throwGLE can also be set on specific operations.

• ns

  The namespace of the collection you are running the operation on, should be of the form "db.collection".

• op

  The type of operation can be "findOne", "find", "insert", "update", "remove", "createIndex", "dropIndex" or "command".

• query

  The query object to use when querying or updating documents.

• update

  The update object (same as 2nd argument of update() function).

• doc

  The document to insert into the database (only for insert and remove).

• safe

  boolean specifies whether to use safe writes (only for update and insert).

• delay

  integer specifies the time to wait between executing the operation.

• skip

  Only applies to find operations. integer specifies the number of documents to skip in a query.

• limit

  Only applies to find operations. integer specifies the number of elements a query should return.

• batchSize

  Only applies to find operations. integer specifies the number of elements the returned cursor should cache.

• filter

  Only applies to find operations. Document specifies which fields should be returned.

• expected

  Only applies to find operations. integer specifies the expected number of elements returned. If the count is not as expected the operation will throw an error. Turning on the handleErrors option allows benchRun to continue if the count was not as expected.

• multi

  boolean specifies whether or not the update or delete should apply to multiple documents. Default value is false.

• upsert

  boolean specifies whether or not an update operation should be run as an upsert. Default value is false.

• key

  Only works for and is required by the createIndex and dropIndex operations. The definition for the index to create or drop.

• showResult

  boolean specifies whether to log the result of each call of the operation.

{ "#RAND_INT" : [ min , max , <multiplier> ] }

• [ 0 , 10 , 4 ] would produce random numbers between 0 and 10 and then multiply by 4.

{ "#RAND_STRING" : [ length ] }

• [ 3 ] would produce a string of 3 random characters.

Dynamic operators generate random strings, random ints, etc but don't work in second level objects, just main level.

• This is fine:

  var complexDoc3 = { info: "#RAND_STRING": [30] } }
  

• This is only going to insert a value called "#RAND_STRING" with an array as a key:

  var complexDoc3 = { info: { inner_field: { "#RAND_STRING": [30] } } }
  

More info:

• Bench Test 1
• Bench Test 2
• Bench Test 3