Production Notes制作说明

x86_64

MongoDB requires the following minimum x86_64 microarchitectures:MongoDB至少需要以下x86_64微体系结构： [2]

• For Intel x86_64, MongoDB requires one of:对于Intel x86_64，MongoDB需要以下选项之一：

  • a Sandy Bridge or later Core processor, orSandy Bridge或更高版本的核心处理器，或
  • a Tiger Lake or later Celeron or Pentium processor.老虎湖或后来的赛扬或奔腾处理器。

• For AMD x86_64, MongoDB requires:对于AMD x86_64，MongoDB需要：

  • a Bulldozer or later processor.推土机或更高版本的处理器。

Starting in MongoDB 5.0, mongod, mongos, and the legacy mongo shell no longer support x86_64 platforms which do not meet this minimum microarchitecture requirement.从MongoDB 5.0开始，mongod、mongos和遗留mongoshell不再支持不满足最低微架构要求的x86_64平台。

ARM64

MongoDB on arm64 requires the ARMv8.2-A or later microarchitecture.arm64上的MongoDB需要ARMv8.2-A或更高版本的微架构。

Starting in MongoDB 5.0, mongod, mongos, and the legacy mongo shell no longer support arm64 platforms which do not meet this minimum microarchitecture requirement.从MongoDB 5.0开始，mongod、mongos和遗留mongoshell不再支持不满足最低微架构要求的arm64平台。

PPC64LE (MongoDB Enterprise Edition)

s390x (MongoDB Community Edition)（MongoDB社区版）

s390x (MongoDB Enterprise Edition)

Containers

WiredTiger

The WiredTiger storage engine is multithreaded and can take advantage of additional CPU cores. WiredTiger存储引擎是多线程的，可以利用额外的CPU内核。Specifically, the total number of active threads (i.e. concurrent operations) relative to the number of available CPUs can impact performance:具体而言，活动线程（即并发操作）的总数相对于可用CPU的数量会影响性能：

• Throughput increases as the number of concurrent active operations increases up to the number of CPUs.吞吐量随着并发活动操作的数量增加到CPU的数量而增加。
• Throughput decreases as the number of concurrent active operations exceeds the number of CPUs by some threshold amount.当并发活动操作的数量超过CPU数量一定阈值时，吞吐量会降低。

The threshold depends on your application. 阈值取决于您的应用程序。You can determine the optimum number of concurrent active operations for your application by experimenting and measuring throughput. 您可以通过实验和测量吞吐量来确定应用程序的最佳并发活动操作数。The output from mongostat provides statistics on the number of active reads/writes in the (ar|aw) column.mongostat的输出提供了（ar|aw）列中活动读/写次数的统计信息。

With WiredTiger, MongoDB utilizes both the WiredTiger internal cache and the filesystem cache.在WiredTiger中，MongoDB同时利用WiredTig内部缓存和文件系统缓存。

Starting in MongoDB 3.4, the default WiredTiger internal cache size is the larger of either:从MongoDB 3.4开始，默认的WiredTiger内部缓存大小为以下值中的较大值：

• 50% of (RAM - 1 GB), or50%（RAM-1 GB），或
• 256 MB.256毫巴。

For example, on a system with a total of 4GB of RAM the WiredTiger cache will use 1.5GB of RAM (0.5 * (4 GB - 1 GB) = 1.5 GB). 例如，在总共有4GB RAM的系统上，WiredTiger缓存将使用1.5GB的RAM（0.5 * (4 GB - 1 GB) = 1.5 GB）。Conversely, a system with a total of 1.25 GB of RAM will allocate 256 MB to the WiredTiger cache because that is more than half of the total RAM minus one gigabyte (0.5 * (1.25 GB - 1 GB) = 128 MB < 256 MB).相反，总RAM为1.25 GB的系统将为WiredTiger缓存分配256 MB，因为这超过了总RAM减去1 GB的一半（0.5 * (1.25 GB - 1 GB) = 128 MB < 256 MB）。

By default, WiredTiger uses Snappy block compression for all collections and prefix compression for all indexes. 默认情况下，WiredTiger对所有集合使用Snappy块压缩，对所有索引使用前缀压缩。Compression defaults are configurable at a global level and can also be set on a per-collection and per-index basis during collection and index creation.压缩默认值可以在全局级别进行配置，也可以在集合和索引创建期间根据每个集合和每个索引进行设置。

Different representations are used for data in the WiredTiger internal cache versus the on-disk format:WiredTiger内部缓存中的数据与磁盘上的数据格式使用不同的表示：

• Data in the filesystem cache is the same as the on-disk format, including benefits of any compression for data files. 文件系统缓存中的数据与磁盘上的格式相同，包括对数据文件进行任何压缩的好处。The filesystem cache is used by the operating system to reduce disk I/O.操作系统使用文件系统缓存来减少磁盘I/O。
• Indexes loaded in the WiredTiger internal cache have a different data representation to the on-disk format, but can still take advantage of index prefix compression to reduce RAM usage. WiredTiger内部缓存中加载的索引具有与磁盘格式不同的数据表示，但仍可以利用索引前缀压缩来减少RAM使用。Index prefix compression deduplicates common prefixes from indexed fields.索引前缀压缩可从索引字段中删除常用前缀。
• Collection data in the WiredTiger internal cache is uncompressed and uses a different representation from the on-disk format. WiredTiger内部缓存中的集合数据未压缩，并使用与磁盘格式不同的表示形式。Block compression can provide significant on-disk storage savings, but data must be uncompressed to be manipulated by the server.块压缩可以显著节省磁盘存储空间，但数据必须解压缩才能由服务器操作。

Via the filesystem cache, MongoDB automatically uses all free memory that is not used by the WiredTiger cache or by other processes.通过文件系统缓存，MongoDB自动使用WiredTiger缓存或其他进程未使用的所有空闲内存。

To adjust the size of the WiredTiger internal cache, see storage.wiredTiger.engineConfig.cacheSizeGB and --wiredTigerCacheSizeGB. 要调整WiredTiger内部缓存的大小，请参阅storage.wiredTiger.engineConfig.cacheSizeGB和--wiredTigerCacheSizeGB。Avoid increasing the WiredTiger internal cache size above its default value.避免将WiredTiger内部缓存大小增加到其默认值以上。

The default WiredTiger internal cache size value assumes that there is a single mongod instance per machine. 默认的WiredTiger内部缓存大小值假定每台机器有一个mongod实例。If a single machine contains multiple MongoDB instances, then you should decrease the setting to accommodate the other mongod instances.如果一台机器包含多个MongoDB实例，那么应该减少设置以适应其他mongod实例。

If you run mongod in a container (e.g. lxc, cgroups, Docker, etc.) that does not have access to all of the RAM available in a system, you must set storage.wiredTiger.engineConfig.cacheSizeGB to a value less than the amount of RAM available in the container. 如果在无法访问系统中所有可用RAM的容器（例如lxc、cgroups、Docker等）中运行mongod，则必须将storage.wiredTiger.engineConfig.cacheSizeGB设置为小于容器中可用RAM量的值。The exact amount depends on the other processes running in the container. 确切的数量取决于容器中运行的其他进程。See memLimitMB.请参阅memLimitMB。

To view statistics on the cache and eviction rate, see the wiredTiger.cache field returned from the serverStatus command.要查看缓存和收回率的统计信息，请参阅serverStatus命令返回的wiredTiger.cache字段。

Compression and Encryption压缩和加密

When using encryption, CPUs equipped with AES-NI instruction-set extensions show significant performance advantages. 使用加密时，配备AES-NI指令集扩展的CPU显示出显著的性能优势。If you are using MongoDB Enterprise with the Encrypted Storage Engine, choose a CPU that supports AES-NI for better performance.如果将MongoDB Enterprise与加密存储引擎一起使用，请选择支持AES-NI的CPU以获得更好的性能。

Configuring NUMA on Windows在Windows上配置NUMA

On Windows, memory interleaving must be enabled through the machine's BIOS. 在Windows上，必须通过计算机的BIOS启用内存交错。Consult your system documentation for details.有关详细信息，请参阅系统文档。

Configuring NUMA on Linux在Linux上配置NUMA

On Linux, you must disable zone reclaim and also ensure that your mongod and mongos instances are started by numactl, which is generally configured through your platform's init system. 在Linux上，您必须禁用区域回收，并确保mongod和mongos实例由numactl启动，通常通过平台的init系统进行配置。You must perform both of these operations to properly disable NUMA for use with MongoDB.您必须执行这两个操作才能正确禁用NUMA以用于MongoDB。

1. Disable zone reclaim with one of the following commands:使用以下命令之一禁用区域回收：

   echo 0 | sudo tee /proc/sys/vm/zone_reclaim_mode

   sudo sysctl -w vm.zone_reclaim_mode=0

2. Ensure that mongod and mongos are started by numactl. 确保mongod和mongos由numactl启动。This is generally configured through your platform's init system. Run the following command to determine which init system is in use on your platform:这通常通过平台的init系统进行配置。运行以下命令以确定您的平台上正在使用哪个init系统：

   ps --no-headers -o comm 1

   • If "systemd", your platform uses the systemd init system, and you must follow the steps in the systemd tab below to edit your MongoDB service file(s).如果为“systemd”，则您的平台使用systemd init系统，您必须按照下面systemd选项卡中的步骤编辑MongoDB服务文件。
   • If "init", your platform uses the SysV Init system, and you do not need to perform this step. 如果“init”，您的平台将使用SysV init系统，您不需要执行此步骤。The default MongoDB init script for SysV Init includes the necessary steps to start MongoDB instances via numactl by default.SysV init的默认MongoDB init脚本包括默认情况下通过numactl启动MongoDB实例的必要步骤。

   • If you manage your own init scripts (i.e. you are not using either of these init systems), you must follow the steps in the Custom init scripts tab below to edit your custom init script(s).如果您管理自己的init脚本（即，您没有使用这些init系统中的任何一个），则必须按照下面“自定义init脚本”选项卡中的步骤来编辑自定义初始化脚本。

     
     
   systemdCustom init scripts自定义初始化脚本

   You must use numactl to start each of your mongod instances, including all config servers, mongos instances, and clients. 必须使用numactl启动每个mongod实例，包括所有配置服务器、mongos实例和客户端。Edit the default systemd service file for each as follows:按如下方式编辑每个系统的默认systemd服务文件：

   1. Copy the default MongoDB service file:复制默认MongoDB服务文件：

      sudo cp /lib/systemd/system/mongod.service /etc/systemd/system/

   2. Edit the /etc/systemd/system/mongod.service file, and update the ExecStart statement to begin with:编辑/etc/systemd/system/mongod.service文件，并更新ExecStart语句以开始：

      /usr/bin/numactl --interleave=all

      Example示例

      If your existing ExecStart statement reads:如果现有的ExecStart语句为：

      ExecStart=/usr/bin/mongod --config /etc/mongod.conf

      Update that statement to read:将该语句更新为：

      ExecStart=/usr/bin/numactl --interleave=all /usr/bin/mongod --config /etc/mongod.conf

   3. Apply the change to systemd:将更改应用于systemd：

      sudo systemctl daemon-reload

   4. Restart any running mongod instances:重新启动所有正在运行的mongod实例：

      sudo systemctl stop mongod
      sudo systemctl start mongod

   5. If applicable, repeat these steps for any mongos instances.如果适用，对任何mongos实例重复这些步骤。

   You must use numactl to start each of your mongod instances, including all config servers, mongos instances, and clients.必须使用numactl启动每个mongod实例，包括所有配置服务器、mongos实例和客户端。

   1. Install numactl for your platform if not already installed. 如果尚未安装，请为您的平台安装numactl。Refer to the documentation for your operating system for information on installing the numactl package.有关安装numactl包的信息，请参阅操作系统的文档。

   2. Configure each of your custom init scripts to start each MongoDB instance via numactl:配置每个自定义初始化脚本，通过numactl启动每个MongoDB实例：

      numactl --interleave=all <path> <options>

      Where <path> is the path to the program you are starting and <options> are any optional arguments to pass to that program.其中<path>是您正在启动的程序的路径，<options>是传递给该程序的任何可选参数。

      Example

      numactl --interleave=all /usr/local/bin/mongod -f /etc/mongod.conf

For more information, see the Documentation for /proc/sys/vm/*.有关详细信息，请参阅/proc/sys/vm/*的文档。

Swap

MongoDB performs best where swapping can be avoided or kept to a minimum, as retrieving data from swap will always be slower than accessing data in RAM. MongoDB在可以避免交换或将交换保持在最低限度的地方表现最好，因为从交换中检索数据总是比访问RAM中的数据慢。However, if the system hosting MongoDB runs out of RAM, swapping can prevent the Linux OOM Killer from terminating the mongod process.但是，如果托管MongoDB的系统内存不足，交换可以防止Linux OOM Killer终止mongod进程。

Generally, you should choose one of the following swap strategies:通常，您应该选择以下掉期策略之一：

1. Assign swap space on your system, and configure the kernel to only permit swapping under high memory load, or在系统上分配交换空间，并将内核配置为仅允许在高内存负载下进行交换，或者
2. Do not assign swap space on your system, and configure the kernel to disable swapping entirely不要在系统上分配交换空间，并将内核配置为完全禁用交换

See Set vm.swappiness for instructions on configuring swap on your Linux system following these guidelines.请参阅Set vm.swapiness，了解有关按照这些指导原则在Linux系统上配置swap的说明。

RAID

For optimal performance in terms of the storage layer, use disks backed by RAID-10. 为了在存储层方面获得最佳性能，请使用RAID-10支持的磁盘。RAID-5 and RAID-6 do not typically provide sufficient performance to support a MongoDB deployment.RAID-5和RAID-6通常不能提供足够的性能来支持MongoDB部署。

Remote Filesystems (NFS)远程文件系统（NFS）

With the WiredTiger storage engine, WiredTiger objects may be stored on remote file systems if the remote file system conforms to ISO/IEC 9945-1:1996 (POSIX.1). 使用WiredTiger存储引擎，如果远程文件系统符合ISO/IEC 9945-1:1996(POSIX.1），则WiredTig对象可以存储在远程文件系统上。Because remote file systems are often slower than local file systems, using a remote file system for storage may degrade performance.由于远程文件系统通常比本地文件系统慢，因此使用远程文件系统进行存储可能会降低性能。

If you decide to use NFS, add the following NFS options to your /etc/fstab file:如果决定使用NFS，请将以下NFS选项添加到/etc/fstab文件中：

• bg
• hard
• nolock
• noatime
• nointr

Depending on your kernel version, some of these values may already be set as the default. 根据您的内核版本，其中一些值可能已经设置为默认值。Consult your platform's documentation for more information.有关详细信息，请参阅您平台的文档。

Separate Components onto Different Storage Devices将组件分离到不同的存储设备上

For improved performance, consider separating your database's data, journal, and logs onto different storage devices, based on your application's access and write pattern. 为了提高性能，请考虑根据应用程序的访问和写入模式将数据库的数据、日志和日志分离到不同的存储设备上。Mount the components as separate filesystems and use symbolic links to map each component's path to the device storing it.将组件作为单独的文件系统挂载，并使用符号链接将每个组件的路径映射到存储它的设备。

For the WiredTiger storage engine, you can also store the indexes on a different storage device. 对于WiredTiger存储引擎，您还可以将索引存储在不同的存储设备上。See storage.wiredTiger.engineConfig.directoryForIndexes.请参阅storage.wiredTiger.engineConfig.directoryForIndexes。

Scheduling行程安排

Kernel and File Systems

When running MongoDB in production on Linux, you should use Linux kernel version 2.6.36 or later, with either the XFS or EXT4 filesystem. 在Linux上的生产环境中运行MongoDB时，应使用Linux内核版本2.6.36或更高版本，以及XFS或EXT4文件系统。If possible, use XFS as it generally performs better with MongoDB.如果可能，请使用XFS，因为它通常在MongoDB中表现更好。

With the WiredTiger storage engine, using XFS is strongly recommended for data bearing nodes to avoid performance issues that may occur when using EXT4 with WiredTiger.对于WiredTiger存储引擎，强烈建议数据承载节点使用XFS，以避免将EXT4与WiredTiger一起使用时可能出现的性能问题。

• In general, if you use the XFS file system, use at least version 2.6.25 of the Linux Kernel.通常，如果您使用XFS文件系统，请至少使用Linux内核2.6.25版本。

• If you use the EXT4 file system, use at least version 2.6.28 of the Linux Kernel.如果使用EXT4文件系统，请至少使用Linux内核2.6.28版本。
• On Red Hat Enterprise Linux and CentOS, use at least version 2.6.18-194 of the Linux kernel.在Red Hat Enterprise Linux和CentOS上，至少使用2.6.18-194版本的Linux内核。

System C Library系统C库

MongoDB uses the GNU C Library(glibc) on Linux. MongoDB在Linux上使用GNU C库（glibc）。Generally, each Linux distro provides its own vetted version of this library. 通常，每个Linux发行版都会提供这个库的自己的经过审查的版本。For best results, use the latest update available for this system-provided version. You can check whether you have the latest version installed by using your system's package manager. 为了获得最佳效果，请使用此系统提供版本的最新更新。您可以使用系统的软件包管理器检查是否安装了最新版本。For example:例如：

• On RHEL / CentOS, the following command updates the system-provided GNU C Library:在RHEL/CentOS上，以下命令更新系统提供的GNU C库：

  sudo yum update glibc

• On Ubuntu / Debian, the following command updates the system-provided GNU C Library:在Ubuntu/Debian上，以下命令更新系统提供的GNU C库：

  sudo apt-get install libc6

fsync() on Directories目录上的fsync()

Set vm.swappiness to 1 or 0将vm.swapiness设置为1或0

“Swappiness” is a Linux kernel setting that influences the behavior of the Virtual Memory manager. “Swappiness”是影响虚拟内存管理器行为的Linux内核设置。The vm.swappiness setting ranges from 0 to 100: the higher the value, the more strongly it prefers swapping memory pages to disk over dropping pages from RAM.vm.swapiness设置的范围从0到100：该值越高，它越倾向于将内存页面交换到磁盘，而不是从RAM中删除页面。

• A setting of 0 disables swapping entirely设置为0将完全禁用交换 [3].
• A setting of 1 permits the kernel to swap only to avoid out-of-memory problems.设置为1只允许内核交换以避免内存不足问题。
• A setting of 60 tells the kernel to swap to disk often, and is the default value on many Linux distributions.设置为60告诉内核经常交换到磁盘，这是许多Linux发行版的默认值。
• A setting of 100 tells the kernel to swap aggressively to disk.设置为100会告诉内核积极地交换到磁盘。

MongoDB performs best where swapping can be avoided or kept to a minimum. MongoDB在可以避免交换或将交换保持在最低限度的地方表现最佳。As such you should set vm.swappiness to either 1 or 0 depending on your application needs and cluster configuration.因此，您应该根据应用程序需求和集群配置将vm.swapiness设置为1或0。

• To check the current swappiness setting on your system, run:要检查系统上的当前交换设置，请运行：

  cat /proc/sys/vm/swappiness

• To change swappiness on your system:要更改系统上的交换：

  1. Edit the /etc/sysctl.conf file and add the following line:编辑/etc/sysctl.conf文件并添加以下行：

     vm.swappiness = 1

  2. Run the following command to apply the setting:运行以下命令以应用设置：

     sudo sysctl -p

Recommended Configuration建议的配置

For all MongoDB deployments:对于所有MongoDB部署：

• Use the Network Time Protocol (NTP) to synchronize time among your hosts. 使用网络时间协议（NTP）在主机之间同步时间。This is especially important in sharded clusters.这在分片集群中尤为重要。

For the WiredTiger storage engines, consider the following recommendations:对于WiredTiger存储引擎，请考虑以下建议：

• Turn off atime for the storage volume containing the database files.关闭包含数据库文件的存储卷的atime。

• Adjust the ulimit settings for your platform according to the recommendations in the ulimit reference. 根据ulimit参考中的建议调整平台的ulimit设置。Low ulimit values will negatively affect MongoDB when under heavy use and can lead to failed connections to MongoDB processes and loss of service.低ulimit值将在大量使用时对MongoDB产生负面影响，并可能导致与MongoDB进程的连接失败和服务丢失。

  Note注意

  Starting in MongoDB 4.4, a startup error is generated if the ulimit value for number of open files is under 64000.从MongoDB 4.4开始，如果打开文件数的ulimit值低于64000，则会生成启动错误。

• Disable Transparent Huge Pages. MongoDB performs better with normal (4096 bytes) virtual memory pages. 禁用透明大页面。MongoDB在使用普通（4096字节）虚拟内存页时性能更好。See Transparent Huge Pages Settings.请参见透明大页面设置。
• Disable NUMA in your BIOS. If that is not possible, see MongoDB on NUMA Hardware.在BIOS中禁用NUMA。如果不可能，请参阅NUMA硬件上的MongoDB。

• Configure SELinux for MongoDB if you are not using the default MongoDB directory paths or ports.如果未使用默认MongoDB目录路径或端口，请为MongoDB配置SELinux。

  Note注意

  If you are using SELinux, any MongoDB operation that requires server-side JavaScript will result in segfault errors. 如果您使用SELinux，任何需要服务器端JavaScript的MongoDB操作都会导致segfault错误。Disable Server-Side Execution of JavaScript describes how to disable execution of server-side JavaScript.禁用服务器端JavaScript的执行描述了如何禁用服务器端JavaScript的执行。

For the WiredTiger storage engine:对于WiredTiger存储引擎：

• Set the readahead setting between 8 and 32 regardless of storage media type (spinning disk, SSD, etc.).无论存储介质类型（旋转磁盘、SSD等）如何，都将预读设置设置在8和32之间。

  Higher readahead commonly benefits sequential I/O operations. 较高的预读通常有利于顺序I/O操作。Since MongoDB disk access patterns are generally random, using higher readahead settings provides limited benefit or potential performance degradation. 由于MongoDB磁盘访问模式通常是随机的，因此使用较高的预读设置只能带来有限的好处或潜在的性能下降。As such, for optimal MongoDB performance, set readahead between 8 and 32, unless testing shows a measurable, repeatable, and reliable benefit in a higher readahead value. 因此，为了获得最佳的MongoDB性能，请将readahead设置在8到32之间，除非测试显示较高的readahea值具有可测量、可重复和可靠的优点。MongoDB commercial support can provide advice and guidance on alternate readahead configurations.可以提供关于备用预读配置的建议和指导。

MongoDB and TLS/SSL LibrariesMongoDB和TLS/SSL库

On Linux platforms, you may observe one of the following statements in the MongoDB log:在Linux平台上，您可以在MongoDB日志中观察到以下语句之一：

<path to TLS/SSL libs>/libssl.so.<version>: no version information available (required by /usr/bin/mongod)
<path to TLS/SSL libs>/libcrypto.so.<version>: no version information available (required by /usr/bin/mongod)

These warnings indicate that the system's TLS/SSL libraries are different from the TLS/SSL libraries that the mongod was compiled against. 这些警告表明系统的TLS/SSL库与mongod编译时使用的TLS/SSL库不同。Typically these messages do not require intervention; however, you can use the following operations to determine the symbol versions that mongod expects:通常，这些信息不需要干预；但是，您可以使用以下操作来确定mongod期望的符号版本：

objdump -T <path to mongod>/mongod | grep " SSL_"
objdump -T <path to mongod>/mongod | grep " CRYPTO_"

These operations will return output that resembles one the of the following lines:这些操作将返回类似于以下行之一的输出：

0000000000000000
      DF *UND*
       0000000000000000  libssl.so.10 SSL_write
0000000000000000
      DF *UND*
       0000000000000000  OPENSSL_1.0.0 SSL_write

The last two strings in this output are the symbol version and symbol name. 此输出中的最后两个字符串是符号版本和符号名称。Compare these values with the values returned by the following operations to detect symbol version mismatches:将这些值与以下操作返回的值进行比较，以检测符号版本不匹配：

objdump -T <path to TLS/SSL libs>/libssl.so.1*
objdump -T <path to TLS/SSL libs>/libcrypto.so.1*

This procedure is neither exact nor exhaustive: many symbols used by mongod from the libcrypto library do not begin with CRYPTO_.这个过程既不精确也不详尽：mongod从libcrypto库中使用的许多符号都不是以CRYPTO_开头的。

AWS EC2

There are two performance configurations to consider:有两种性能配置需要考虑：

• Reproducible performance for performance testing or benchmarking, and用于性能测试或基准测试的可复制性能，以及
• Raw maximum performance原始最大性能

To tune performance on EC2 for either configuration, you should:要为两种配置调优EC2上的性能，您应该：

• Enable AWS Enhanced Networking for your instance. 为您的实例启用AWS增强型网络。Not all instance types support Enhanced Networking.并非所有实例类型都支持增强型网络。

  To learn more about Enhanced Networking, see to the AWS documentation.要了解有关增强型网络的更多信息，请参阅AWS文档。

If you are concerned more about reproducible performance on EC2, you should also:如果您更关心EC2的可复制性能，您还应：

• Use provisioned IOPS for the storage, with separate devices for journal and data. 为存储使用配置的IOPS，日志和数据使用单独的设备。Do not use the ephemeral (SSD) storage available on most instance types as their performance changes moment to moment. 不要使用大多数实例类型上可用的临时（SSD）存储，因为它们的性能会随时变化。(The i series is a notable exception, but very expensive.)（i系列是一个显著的例外，但非常昂贵。）

• Disable DVFS and CPU power saving modes.禁用DVFS和CPU节能模式。

  Tip提示

  See also: 参阅：

  Amazon documentation on Processor State Control亚马逊关于处理器状态控制的文档

• Disable hyperthreading.禁用超读。

  Tip提示

  See also: 参阅：

  Amazon blog post on disabling Hyper-Threading亚马逊关于禁用超线程的博客文章.

• Use numactl to bind memory locality to a single socket.使用numactl将内存位置绑定到单个套接字。

Azure

Use Premium Storage. 使用高级存储。Microsoft Azure offers two general types of storage: Standard storage, and Premium storage. Microsoft Azure提供两种一般类型的存储：标准存储和高级存储。MongoDB on Azure has better performance when using Premium storage than it does with Standard storage.Azure上的MongoDB在使用高级存储时比使用标准存储时具有更好的性能。

The TCP idle timeout on the Azure load balancer is 240 seconds by default, which can cause it to silently drop connections if the TCP keepalive on your Azure systems is greater than this value. 默认情况下，Azure负载平衡器上的TCP空闲超时为240秒，如果您的Azure系统上的TCP保持活动状态大于此值，这可能会导致它静默地断开连接。You should set tcp_keepalive_time to 120 to ameliorate this problem.您应该将tcp_keepalive_time设置为120以改善此问题。

• To view the keepalive setting on Linux, use one of the following commands:要查看Linux上的keepalive设置，请使用以下命令之一：

  sysctl net.ipv4.tcp_keepalive_time

  Or:或者：

  cat /proc/sys/net/ipv4/tcp_keepalive_time

  The value is measured in seconds.该值以秒为单位测量。

  Note注意

  Although the setting name includes ipv4, the tcp_keepalive_time value applies to both IPv4 and IPv6.尽管设置名称包括ipv4，但tcp_keepalive_time值同时适用于ipv4和IPv6。

• To change the tcp_keepalive_time value, you can use one of the following commands, supplying a <value> in seconds:要更改tcp_keepalive_time值，可以使用以下命令之一，以秒为单位提供<value>：

  sudo sysctl -w net.ipv4.tcp_keepalive_time=<value>

  Or:或者：

  echo <value> | sudo tee /proc/sys/net/ipv4/tcp_keepalive_time

  These operations do not persist across system reboots. 这些操作不会在系统重新启动期间持续。To persist the setting, add the following line to /etc/sysctl.conf, supplying a <value> in seconds, and reboot the machine:要保持该设置，请将以下行添加到/etc/sysctl.conf中，以秒为单位提供<value>，然后重新启动计算机：

  net.ipv4.tcp_keepalive_time = <value>

  Keepalive values greater than 300 seconds, (5 minutes) will be overridden on mongod and mongos sockets and set to 300 seconds.大于300秒（5分钟）的Keepalive值将在mongod和mongos套接字上被覆盖，并设置为300秒。

• To view the keepalive setting on Windows, issue the following command:要在Windows上查看keepalive设置，请发出以下命令：

  reg query HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters /v KeepAliveTime

  The registry value is not present by default. 默认情况下，注册表值不存在。The system default, used if the value is absent, is 7200000 milliseconds or 0x6ddd00 in hexadecimal.如果该值不存在，则使用系统默认值为7200000毫秒或0x6ddd00（十六进制）。

  
  

• To change the KeepAliveTime value, use the following command in an Administrator Command Prompt, where <value> is expressed in hexadecimal (e.g. 120000 is 0x1d4c0):要更改KeepAliveTime值，请在管理员命令提示符中使用以下命令，其中<value>以十六进制表示（例如120000为0x1d4c0）：

  reg add HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ /t REG_DWORD /v KeepAliveTime /d <value>

  Windows users should consider the Windows Server Technet Article on KeepAliveTime for more information on setting keepalive for MongoDB deployments on Windows systems. Windows用户应考虑有关KeepAliveTime的Windows Server Technet文章，以了解有关在Windows系统上为MongoDB部署设置keepalive的更多信息。Keepalive values greater than or equal to 600000 milliseconds (10 minutes) will be ignored by mongod and mongos.大于或等于600000毫秒（10分钟）的Keepalive值将被mongod和mongos忽略。

VMware

MongoDB is compatible with VMware.MongoDB与VMware兼容。

VMware supports memory overcommitment, where you can assign more memory to your virtual machines than the physical machine has available. VMware支持内存超量使用，您可以为虚拟机分配比物理机可用内存更多的内存。When memory is overcommitted, the hypervisor reallocates memory between the virtual machines. 当内存超量使用时，虚拟机监控程序会在虚拟机之间重新分配内存。VMware's balloon driver (vmmemctl) reclaims the pages that are considered least valuable.VMware的气球驱动程序（vmmemctl）回收被认为最不值钱的页面。

The balloon driver resides inside the guest operating system. 气球驱动程序驻留在来宾操作系统中。When the balloon driver expands, it may induce the guest operating system to reclaim memory from guest applications, which can interfere with MongoDB's memory management and affect MongoDB's performance.当气球驱动程序扩展时，它可能会导致来宾操作系统从来宾应用程序中回收内存，这会干扰MongoDB的内存管理并影响MongoDB性能。

Do not disable the balloon driver and memory overcommitment features. 不要禁用气球驱动程序和内存超限功能。This can cause the hypervisor to use its swap which will affect performance. 这可能导致虚拟机监控程序使用其交换，从而影响性能。Instead, map and reserve the full amount of memory for the virtual machine running MongoDB. 相反，映射并保留运行MongoDB的虚拟机的全部内存。This ensures that the balloon will not be inflated in the local operating system if there is memory pressure in the hypervisor due to an overcommitted configuration.这可以确保，如果由于过度提交配置而导致虚拟机监控程序内存压力，则气球不会在本地操作系统中膨胀。

Ensure that virtual machines stay on a specific ESX/ESXi host by setting VMware's affinity rules. 通过设置VMware的关联规则，确保虚拟机位于特定的ESX/ESXi主机上。If you must manually migrate a virtual machine to another host and the mongod instance on the virtual machine is the primary, you must first step down the primary and then shut down the instance.如果您必须手动将虚拟机迁移到另一个主机，并且虚拟机上的mongod实例是primary，则必须首先关闭primary，然后关闭该实例。

Follow the networking best practices for vMotion and the VMKernel. 遵循vMotion和VMKernel的网络最佳实践。Failure to follow the best practices can result in performance problems and affect replica set and sharded cluster high availability mechanisms.不遵循最佳实践可能会导致性能问题，并影响副本集和分片群集的高可用性机制。

It is possible to clone a virtual machine running MongoDB. 可以克隆运行MongoDB的虚拟机。You might use this function to spin up a new virtual host to add as a member of a replica set. 您可以使用此功能启动一个新的虚拟主机，将其添加为副本集的成员。If you clone a VM with journaling enabled, the clone snapshot will be valid. 如果克隆启用日志记录的VM，克隆快照将有效。If not using journaling, first stop mongod, then clone the VM, and finally, restart mongod.如果不使用日志记录，首先停止mongod，然后克隆VM，最后重新启动mongod。

KVM

MongoDB is compatible with KVM.MongoDB与KVM兼容。

KVM supports memory overcommitment, where you can assign more memory to your virtual machines than the physical machine has available. KVM支持内存超限，您可以为虚拟机分配比物理机可用内存更多的内存。When memory is overcommitted, the hypervisor reallocates memory between the virtual machines. KVM's balloon driver reclaims the pages that are considered least valuable.当内存超量使用时，虚拟机监控程序会在虚拟机之间重新分配内存。KVM的气球驱动程序会回收被认为最没有价值的页面。

The balloon driver resides inside the guest operating system. When the balloon driver expands, it may induce the guest operating system to reclaim memory from guest applications, which can interfere with MongoDB's memory management and affect MongoDB's performance.气球驱动程序驻留在来宾操作系统中。当气球驱动程序扩展时，它可能会导致来宾操作系统从来宾应用程序中回收内存，这会干扰MongoDB的内存管理并影响MongoDB性能。

Do not disable the balloon driver and memory overcommitment features. 不要禁用气球驱动程序和内存超限功能。This can cause the hypervisor to use its swap which will affect performance. 这可能导致虚拟机监控程序使用其交换，从而影响性能。Instead, map and reserve the full amount of memory for the virtual machine running MongoDB. 相反，映射并保留运行MongoDB的虚拟机的全部内存。This ensures that the balloon will not be inflated in the local operating system if there is memory pressure in the hypervisor due to an overcommitted configuration.这可以确保，如果由于过度提交配置而导致虚拟机监控程序内存压力，则气球不会在本地操作系统中膨胀。