Run-time Database Configuration运行时数据库配置

Configure the Database配置数据库

Consider the following basic configuration:考虑以下基本配置：

processManagement:
   fork: true
net:
   bindIp: localhost
   port: 27017
storage:
   dbPath: /var/lib/mongo
systemLog:
   destination: file
   path: "/var/log/mongodb/mongod.log"
   logAppend: true
storage:
   journal:
      enabled: true

For most standalone servers, this is a sufficient base configuration. 对于大多数独立服务器，这是一个足够的基本配置。It makes several assumptions, but consider the following explanation:它做了几个假设，但是考虑下面的解释：

• fork is true, which enables a daemon mode for mongod, which detaches (i.e. "forks") the MongoDB from the current session and allows you to run the database as a conventional server.是true，这将为mongod启用守护程序模式，将MongoDB从当前会话中分离（即“分叉”），并允许您将数据库作为常规服务器运行。

• bindIp is localhost, which forces the server to only listen for requests on the localhost IP. 是localhost，它强一致性务器只侦听本地主机IP上的请求。Only bind to secure interfaces that the application-level systems can access with access control provided by system network filtering (i.e. "firewall").仅绑定到应用级系统可以通过系统网络筛选（即“防火墙”）提供的访问控制访问的安全接口。

• port is 27017, which is the default MongoDB port for database instances. 是27017，这是数据库实例的默认MongoDB端口。MongoDB can bind to any port. MongoDB可以绑定到任何端口。You can also filter access based on port using network filtering tools.您还可以使用网络筛选工具根据端口筛选访问。

  Note注意

  UNIX-like systems require superuser privileges to attach processes to ports lower than 1024.类UNIX系统需要超级用户权限才能将进程连接到1024以下的端口。

• quiet is true. 这是true。This disables all but the most critical entries in output/log file, and is notrecommended for production systems. 这将禁用输出/日志文件中除最关键的条目外的所有条目，不建议用于生产系统。If you do set this option, you can use setParameter to modify this setting during run time.如果设置了此选项，则可以在运行时使用setParameter修改此设置。

• dbPath is /var/lib/mongo, which specifies where MongoDB will store its data files.是/var/lib/mongo，它指定MongoDB将存储其数据文件的位置。

  If you installed MongoDB on Linux using a package manager, such as yum or apt, the /etc/mongod.conf file provided with your MongoDB installation sets the following default dbPath, depending on your Linux distro:如果您在Linux上使用软件包管理器（如yum或apt）安装了MongoDB，则MongoDB安装附带的/etc/mongod.conf文件将根据您的Linux发行版设置以下默认数据库路径：

  Platform平台	Package Manager软件包管理器	Default 默认dbPath
  RHEL / CentOS and Amazon	yum	/var/lib/mongo
  SUSE	zypper	/var/lib/mongo
  Ubuntu and Debian	apt	/var/lib/mongodb
  macOS	brew	/usr/local/var/mongodb

  The user account that mongod runs under will need read and write access to this directory.mongod运行的用户帐户需要对该目录进行读写访问。

• systemLog.path is /var/log/mongodb/mongod.log which is where mongod will write its output. 是/var/log/mongodb/mongod.log，mongod将在其中写入其输出。If you do not set this value, mongod writes all output to standard output (e.g. stdout.)如果不设置此值，mongod会将所有输出写入标准输出（例如stdout）
• logAppend is true, which ensures that mongod does not overwrite an existing log file following the server start operation.为true，这确保mongod不会在服务器启动操作后覆盖现有日志文件。
• storage.journal.enabled is true, which enables journaling. 是true，这使日志记录成为可能。Journaling ensures single instance write-durability. 日志记录确保了单实例写入的持久性。64-bit builds of mongod enable journaling by default. 默认情况下，mongod的64位版本支持日志记录。Thus, this setting may be redundant.因此，该设置可能是多余的。

Given the default configuration, some of these values may be redundant. 给定默认配置，其中一些值可能是多余的。However, in many situations explicitly stating the configuration increases overall system intelligibility.然而，在许多情况下，明确说明配置会提高整个系统的可理解性。

Security Considerations安全考虑

The following configuration options are useful for limiting access to a mongod instance:以下配置选项可用于限制对mongod实例的访问：

net:
   bindIp: localhost,10.8.0.10,192.168.4.24,/tmp/mongod.sock
security:
   authorization: enabled

net.bindIp

This example provides four values to the bindIp option:本例为bindIp选项提供了四个值：

• localhost, the localhost interface;，本地主机接口；
• 10.8.0.10, a private IP address typically used for local networks and VPN interfaces;，一个专用IP地址，通常用于本地网络和VPN接口；
• 192.168.4.24, a private network interface typically used for local networks; and，通常用于本地网络的专用网络接口；和
• /tmp/mongod.sock, a Unix domain socket path.，一个Unix域套接字路径。

Because production MongoDB instances need to be accessible from multiple database servers, it is important to bind MongoDB to multiple interfaces that are accessible from your application servers. 由于生产MongoDB实例需要可从多个数据库服务器访问，因此将MongoDB绑定到可从应用服务器访问的多个接口非常重要。At the same time it's important to limit these interfaces to interfaces controlled and protected at the network layer.同时，将这些接口限制为网络层控制和保护的接口也很重要。

security.authorization

Setting this option to true enables the authorization system within MongoDB. 将此选项设置为true将启用MongoDB中的授权系统。If enabled you will need to log in by connecting over the localhost interface for the first time to create user credentials.如果启用，您将需要首次通过localhost接口连接登录以创建用户凭据。

Replication and Sharding Configuration复制和分分片配置

replication:
   replSetName: set0

security:
   keyFile: /srv/mongodb/keyfile

 sharding:
    clusterRole: configsvr
 net:
    bindIp: 10.8.0.12
    port: 27001
replication:
    replSetName: csRS

sharding:
   clusterRole: shardsvr
replication:
   replSetName: shardA

sharding:
   configDB: csRS/10.8.0.12:27001

Run Multiple Database Instances on the Same System在同一系统上运行多个数据库实例

In many cases running multiple instances of mongod on a single system is not recommended. 在许多情况下，不建议在单个系统上运行多个mongod实例。On some types of deployments [2] and for testing purposes you may need to run more than one mongod on a single system.在某些类型的部署[2]上，出于测试目的，您可能需要在单个系统上运行多个mongod。

In these cases, use a base configuration for each instance, but consider the following configuration values:在这些情况下，为每个实例使用基本配置，但请考虑以下配置值：

storage:
   dbPath: /var/lib/mongo/db0/
processManagement:
   pidFilePath: /var/lib/mongo/db0.pid

The dbPath value controls the location of the mongod instance's data directory. dbPath值控制mongod实例的数据目录的位置。Ensure that each database has a distinct and well labeled data directory. 确保每个数据库都有一个明确且标记良好的数据目录。The pidFilePath controls where mongod process places it's process id (PID) file. pidFilePath控制mongod进程将其进程id（PID）文件放置在何处。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.由于这会跟踪特定的mongod文件，所以文件必须是唯一的，并且标记良好，以便轻松启动和停止这些过程。

Create additional init scripts and/or adjust your existing MongoDB configuration and init script as needed to control these processes.根据需要创建其他初始化脚本和/或调整现有MongoDB配置和初始化脚本，以控制这些进程。

Diagnostic Configurations诊断配置

The following configuration options control various mongod behaviors for diagnostic purposes:以下配置选项控制各种mongod行为以进行诊断：

• operationProfiling.mode sets the database profiler level. 设置数据库探查器级别。The profiler is not active by default because of the possible impact on the profiler itself on performance. 默认情况下，探查器不处于活动状态，因为探查器本身可能会对性能产生影响。Unless this setting is on, queries are not profiled.除非启用此设置，否则不会分析查询。

• operationProfiling.slowOpThresholdMs configures the threshold which determines whether a query is "slow" for the purpose of the logging system and the profiler. 为日志系统和探查器配置用于确定查询是否“缓慢”的阈值。The default value is 100 milliseconds. 默认值为100毫秒。Set to a lower value if the logging system and the database profiler do not return useful results or set to a higher value to only log the longest running queries.如果日志记录系统和数据库探查器未返回有用的结果，请将其设置为较低的值，或者将其设置为较高的值，以便仅记录运行时间最长的查询。

  Starting in version 4.2 (also available starting in 4.0.6), secondary members of a replica set now log oplog entries that take longer than the slow operation threshold to apply. 从版本4.2开始（也可从4.0.6开始使用），副本集的次要成员现在会记录需要比慢速操作阈值更长时间才能应用的oplog条目。These slow oplog messages:这些缓慢的oplog消息：

  • Are logged for the secondaries in the diagnostic log.在诊断日志中记录辅助设备的。
  • Are logged under the REPL component with the text applied op: <oplog entry> took <num>ms.记录在REPL组件下，文本为applied op: <oplog entry> took <num>ms。
  • Do not depend on the log levels (either at the system or component level)不要依赖于日志级别（系统或组件级别）
  • Do not depend on the profiling level.不要依赖于分析级别。

  • May be affected by slowOpSampleRate, depending on your MongoDB version:可能会受到slowOpSampleRate的影响，具体取决于您的MongoDB版本：

    • In MongoDB 4.2 and earlier, these slow oplog entries are not affected by the slowOpSampleRate. 在MongoDB 4.2及更早版本中，这些缓慢的oplog条目不受slowOpSampleRate的影响。MongoDB logs all slow oplog entries regardless of the sample rate.无论采样率如何，MongoDB都会记录所有慢速oplog条目。
    • In MongoDB 4.4 and later, these slow oplog entries are affected by the slowOpSampleRate.在MongoDB 4.4及更高版本中，这些较慢的oplog条目会受到slowOpSampleRate的影响。

  The profiler does not capture slow oplog entries.探查器不会捕获较慢的oplog条目。

• systemLog.verbosity controls the amount of logging output that mongod write to the log. 控制mongod写入日志的日志输出量。Only use this option if you are experiencing an issue that is not reflected in the normal logging level.仅当遇到正常日志记录级别中未反映的问题时，才使用此选项。

  Starting in MongoDB 3.0, you can also specify verbosity level for specific components using the systemLog.component.<name>.verbosity setting. 从MongoDB 3.0开始，还可以使用systemLog.component.<name>.verbosity设置为特定组件指定详细级别。For the available components, see component verbosity settings.有关可用组件，请参阅组件详细度设置。

For more information, see also Database Profiling and MongoDB Performance.有关更多信息，请参阅数据库评测和MongoDB性能。