MongoDB Documentation, Release 3.0.4 Diagnostic Configurations Production Notes MongoDB file. As this tracks the specific mongod file, it is crucial that file be unique and well labeled to make it easy to start and stop these processes. Create additional control scripts and/or adjust your existing MongoDB configuration and control script as needed to control these processes. The following configuration options control various mongod behaviors for diagnostic purposes: For more information, see also Database Profiling (page 215) and Analyzing MongoDB Performance (page 213). This page details system configurations that affect MongoDB, especially in production. Note: MongoDB Cloud Manager$^{55}$, a hosted service, and Ops Manager$^{56}$, an on-premise solution, provide monitor- ing, backup, and automation of MongoDB instances. See the MongoDB Cloud Manager documentation 57 and Ops Manager documentation 58 for more information. Storage Engines Changed in version 3.0: MongoDB includes support for two storage engines: MMAPv1 (page 91), the storage engine available in previous versions of MongoDB, and WiredTiger (page 90). MongoDB uses the MMAPv1 engine by default. The files in the dbPath directory must correspond to the configured storage engine. mongod will not start if dbPath contains data files created by a storage engine other than the one specified by --storageEngine . Supported Platforms MongoDB distributions are currently available for Mac OS X, Linux, Windows Server 2012, Windows Server 2008 R2 64bit, Windows 7 (64 bit), Windows Vista, and Solaris. The MongoDB distribution for Solaris does not include support for the WiredTiger storage engine (page 90). 197 5.1. Administration Concepts $^{55}$https://cloud.mongodb.com/?jmp=docs $^{56}$https://www.mongodb.com/products/mongodb-enterprise-advanced?jmp=docs $^{57}$https://docs.cloud.mongodb.com/ $^{58}$https://docs.opsmanager.mongodb.com?jmp=docs • operationProfiling.mode sets the database profiler (page 215) level. The profiler is not active by default because of the possible impact on the profiler itself on performance. Unless this setting is on, queries are not profiled. • operationProfiling.slowOpThresholdMs configures the threshold which determines whether a query is “slow” for the purpose of the logging system and the profiler (page 215). The default value is 100 milliseconds. Set a lower value if the database profiler does not return useful results or a higher value to only log the longest running queries. • systemLog.verbosity controls the amount of logging output that mongod write to the log. Only use this option if you are experiencing an issue that is not reflected in the normal logging level. Changed in version 3.0: You can also specify verbosity level for specific components using the systemLog.component.<name>.verbosity setting. For the available components, see component verbosity settings .