Production Notes for Self-Managed Deployments自我管理部署的生产备忘

WiredTiger

The WiredTiger storage engine is multithreaded and can take advantage of additional CPU cores. Specifically, the total number of active threads (i.e. concurrent operations) relative to the number of available CPUs can impact performance:WiredTiger存储引擎是多线程的，可以利用额外的CPU内核。具体来说，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数量的某个阈值时，吞吐量会降低。

The threshold depends on your application. You can determine the optimum number of concurrent active operations for your application by experimenting and measuring throughput. 阈值取决于应用程序。您可以通过实验和测量吞吐量来确定应用程序并发活动操作的最佳数量。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/写次数的统计数据。

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

The default WiredTiger internal cache size is the larger of either:默认的WiredTiger内部缓存大小是以下两者中的较大值：

• 50% of (RAM - 1 GB), or
• 256 MB.

For example, on a system with a total of 4GB of RAM the WiredTiger cache uses 1.5GB of RAM (0.5 * (4 GB - 1 GB) = 1.5 GB). Conversely, on a system with a total of 1.25 GB of RAM WiredTiger allocates 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).例如，在总共有4GB RAM的系统上，WiredTiger缓存使用1.5GB RAM（0.5 * (4 GB - 1 GB) = 1.5 GB）。相反，在总共有1.25 GB RAM的系统上，WiredTiger将256 MB分配给WiredTigeer缓存，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. 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.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。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:与磁盘格式相比，WiredTiger内部缓存中的数据使用了不同的表示方式：

• Data in the filesystem cache is the same as the on-disk format, including benefits of any compression for data files. The filesystem cache is used by the operating system to reduce disk I/O.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。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. Index prefix compression deduplicates common prefixes from indexed fields.加载在WiredTiger内部缓存中的索引具有与磁盘上格式不同的数据表示形式，但仍然可以利用索引前缀压缩来减少RAM使用。索引前缀压缩可消除索引字段中的常见前缀的重复。
• Collection data in the WiredTiger internal cache is uncompressed and uses a different representation from the on-disk format. Block compression can provide significant on-disk storage savings, but data must be uncompressed to be manipulated by the server.WiredTiger内部缓存中的集合数据是未压缩的，并使用与磁盘格式不同的表示形式。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。

With the filesystem cache, MongoDB automatically uses all free memory that is not used by the WiredTiger cache or by other processes.使用文件系统缓存，MongoDB会自动使用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 --wiredTigerCacheSizeGB and storage.wiredTiger.engineConfig.cacheSizeGB. 要调整WiredTiger内部缓存的大小，请参阅--wiredTigerCacheSizeGB和storage.wiredTiger.engineConfig.cacheSizeGB。Avoid increasing the WiredTiger internal cache size above its default value. 避免将WiredTiger内部缓存大小增加到默认值以上。If your use case requires increased internal cache size, see --wiredTigerCacheSizePct and storage.wiredTiger.engineConfig.cacheSizePct.如果用例需要增加内部缓存大小，请参阅--wiredTigerCacheSizePct和storage.wiredTiger.engineConfig.cacheSizePct。

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只有一个mongod实例。If a single machine contains multiple MongoDB instances, decrease the setting to accommodate the other mongod instances.如果一台机器包含多个MongoDB实例，请减小设置以容纳其他mongod实例。

If you run mongod in a container (for example, 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. 如果你在一个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，你必须将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. See memLimitMB.确切的数量取决于容器中运行的其他进程。请参阅memLimitMB。

You can only provide one of either storage.wiredTiger.engineConfig.cacheSizeGB or storage.wiredTiger.engineConfig.cacheSizePct.您只能提供storage.wiredTiger.engineConfig.cacheSizeGB或storage.wiredTiger.engineConfig.cacheSizePct中的一个。

To view statistics on the cache and eviction rate, see the wiredTiger.cache field returned from the serverStatus command.要查看缓存和驱逐率的统计信息，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. If you are using MongoDB Enterprise with the Encrypted Storage Engine, choose a CPU that supports AES-NI for better performance.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。如果您使用的是带有加密存储引擎的MongoDB Enterprise，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. Consult your system documentation for details.在Windows上，必须通过机器的BIOS启用内存交错。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. You must perform both of these operations to properly disable NUMA for use with MongoDB.在Linux上，您必须禁用区域回收，并确保mongod和mongos实例由numactl启动，numactl通常通过您平台的init系统配置。您必须执行这两个操作才能正确禁用NUMA以与MongoDB一起使用。

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:这通常是通过平台的init系统配置的。运行以下命令以确定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).如果是“systemd”，则平台使用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. The default MongoDB init script for SysV Init includes the necessary steps to start MongoDB instances via numactl by default.如果是“init”，则平台使用SysV init系统，您不需要执行此步骤。SysV init的默认MongoDB初始化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).如果您管理自己的初始化脚本（即您没有使用这两个初始化系统中的任何一个），则必须按照下面“自定义初始化脚本”选项卡中的步骤编辑自定义初始化脚本。

     
     
   Systemd

   You must use numactl to start each of your mongod instances, including all config servers, mongos instances, and clients. 您必须使用numactl来启动每个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的默认systemd服务文件：

   1. Copy the default MongoDB service file:复制默认的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，使其以以下内容开头：

      /usr/bin/numactl --interleave=all

      Example示例

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

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

      Update that statement to read:将该声明更新为：

      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:重新启动任何正在运行的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。
   Custom init scripts

   You must use numactl to start each of your mongod instances, including all config servers, mongos instances, and clients.您必须使用numactl来启动每个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. Refer to the documentation for your operating system for information on installing the numactl package.如果尚未安装，请为平台安装numactl。有关安装numactl软件包的信息，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init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>是您要启动的程序的路径，<options>是传递给该程序的任何可选参数。

      Example示例

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

For more information, see the Documentation for /proc/sys/vm/*.有关更多信息，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在可以避免或尽量减少交换的情况下表现最佳，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杀手终止mongod进程。

Generally, you should choose one of the following swap strategies:通常，您应该选择以下交换策略之一：

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
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.有关按照这些准则在Linux系统上配置交换的说明，请参阅设置vm.swappiness。

RAID

For optimal performance in terms of the storage layer, use disks backed by RAID-10. RAID-5 and RAID-6 do not typically provide sufficient performance to support a MongoDB deployment.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). Because remote file systems are often slower than local file systems, using a remote file system for storage may degrade performance.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WiredTigeer对象可以存储在远程文件系统上。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:如果您决定使用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. Consult your platform's documentation for more information.根据内核版本，其中一些值可能已经设置为默认值。有关更多信息，请参阅平台文档。

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. Mount the components as separate filesystems and use symbolic links to map each component's path to the device storing it.为了提高性能，可以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。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. See storage.wiredTiger.engineConfig.directoryForIndexes.对于WiredTiger存储引擎，您还可以将索引存储在其他存储设备上。请参阅storage.wiredTiger.engineConfig.directoryForIndexes。

Scheduling日程安排

Kernel and File Systems内核和文件系统

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. If possible, use XFS as it generally performs better with MongoDB.在Linux上的生产环境中运行MongoDB时，您应该使用Linux内核版本2.6.36或更高版本，以及XFS或EXT4文件系统。如果可能的话，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，强烈建议对数据承载节点使用XFS，以避免在将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.一般来说，如果您使用XFS文件系统，请至少使用Linux内核的2.6.25版本。
• If you use the EXT4 file system, use at least version 2.6.28 of the Linux Kernel.如果您使用EXT4文件系统，请至少使用Linux内核的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Linux内核的2.6.18-194版本。

System C Library系统C库

MongoDB uses the GNU C Library (glibc) on Linux. Generally, each Linux distro provides its own vetted version of this library. MongoDB在Linux上使用GNU C库（glibc）。通常，每个Linux发行版都提供自己的经过审查的此库版本。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. For example:为了获得最佳效果，请使用此系统提供版本的最新更新。您可以使用系统的包管理器检查是否安装了最新版本。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

Set vm.swappiness to 1 or 0

"Swappiness" is a Linux kernel setting that influences the behavior of the Virtual Memory manager.“Swappiness”是一个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.swappiness设置的范围为0到100：值越高，它越喜欢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[8].
• 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. As such you should set vm.swappiness to either 1 or 0 depending on your application needs and cluster configuration.MongoDB在可以避免交换或将交换保持在最低限度的情况下表现最佳。因此，您应该根据应用程序需求和集群配置将vm.swappiness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swappiness设置，请运行：

  cat /proc/sys/vm/swappiness

• To change swappiness on your system:要更改系统上的swappity，请执行以下操作：

  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推荐配置

For all MongoDB deployments:对于所有MongoDB部署：

• Use the Network Time Protocol (NTP) to synchronize time among your hosts. This is especially important in sharded clusters.使用网络时间协议（NTP）在主机之间同步时间。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值在频繁使用时会对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

  If the ulimit value for number of open files is under 64000, MongoDB generates a startup warning.如果打开文件数的ulimit值低于64000，MongoDB会生成启动警告。

• If you are running MongoDB 8.0, enable Transparent Hugepages.如果您运行的是MongoDB 8.0，请启用透明护圈。

  • If you are running MongoDB 7.0 or earlier, disable Transparent Hugepages. In earlier versions, MongoDB performs better with typical (4096 bytes) virtual memory pages.如果您运行的是MongoDB 7.0或更早版本，请禁用透明护圈。在早期版本中，MongoDB在典型的（4096字节）虚拟内存页面上表现更好。
• Disable NUMA in your BIOS. If that is not possible, see MongoDB on NUMA Hardware.在BIOS中禁用NUMA。如果这不可能，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.如果您没有使用默认的MongoDB目录路径或端口，请为MongoDB配置SELinux。

  Note

  If you are using SELinux, any MongoDB operation that requires server-side JavaScript will result in segfault errors. 如果你使用的是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禁用服务器端执行JavaScript describes how to disable execution of server-side JavaScript.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.).将预读设置设置在8到32之间，而不管存储介质类型（旋转磁盘、SSD等）如何。

  Higher readahead commonly benefits sequential I/O operations. Since MongoDB disk access patterns are generally random, using higher readahead settings provides limited benefit or potential performance degradation. 较高的预读通常有利于顺序I/O操作。由于MongoDB磁盘访问模式通常是随机的，因此使用更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，请将预读设置在8到32之间，除非测试显示在更高的预读值中有可衡量、可重复和可靠的好处。MongoDB commercial support商业支持 can provide advice and guidance on alternate readahead configurations.可以就替代预读配置提供建议和指导。

MongoDB and TLS/SSL Libraries以及TLS/SSL库

On Linux platforms, you may observe one of the following statements in the MongoDB log:在Linux平台上，您可能会在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，这些消息不需要干预；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. Compare these values with the values returned by the following operations to detect symbol version mismatches:此输出中的最后两个字符串是符号版本和符号名称。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在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再现性能，以及
• Raw maximum performance原始最大性能

To tune performance on EC2 for either configuration, you should:要调整EC2上任一配置的性能，您应该：

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

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

• Set tcp_keepalive_time to 120.将tcp_kealive_time设置为120。

If you are concerned more about reproducible performance on EC2, you should also:如果您更关心EC2上的可重复性能，您还应该：

• Use provisioned IOPS for the storage, with separate devices for journal and data. Do not use the ephemeral (SSD) storage available on most instance types as their performance changes moment to moment. (The i series is a notable exception, but very expensive.)为存储使用配置的IOPS，日志和数据使用单独的设备。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发生变化。（i系列是一个明显的例外，但非常昂贵。）

• Disable DVFS and CPU power saving modes.禁用DVFS和CPU省电模式。

  Tip

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

• Disable hyperthreading.禁用超线程。

  Tip

  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. Microsoft Azure offers two general types of storage: Standard storage, and Premium storage. MongoDB on Azure has better performance when using Premium storage than it does with Standard storage.使用高级存储。Microsoft Azure提供两种通用类型的存储：标准存储和高级存储。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。

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. When memory is overcommitted, the hypervisor reallocates memory between the virtual machines. VMware支持内存超量使用，您可以为虚拟机分配比物理机可用的更多内存。当内存超量使用时，管理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）回收被认为价值最低的页面。

The balloon driver resides inside the guest operating system. Under certain configurations, when the balloon driver expands, it can interfere with MongoDB's memory management and affect MongoDB's performance.气球驱动程序位于客户操作系统内部。在某些配置下，当气球驱动程序扩展时，它可能会干扰MongoDB的内存管理并影响MongoDB的性能。

To prevent negative performance impact from the balloon driver and memory overcommitment features, reserve the full amount of memory for the virtual machine running MongoDB. Reserving the appropriate amount of memory for the virtual machine prevents the balloon from inflating in the local operating system when there is memory pressure in the hypervisor.为了防止气球驱动程序和内存超量使用功能对性能产生负面影响，请为运行MongoDB的虚拟机保留全部内存。为虚拟机保留适量的内存可以防止在管理程序内存压力时气球在本地操作系统中膨胀。

Even though the balloon driver and memory overcommitment features can negatively affect MongoDB performance under certain configurations, do not disable these features. If you disable these features, the hypervisor may use its swap space to fulfill memory requests, which negatively affects performance.即使气球驱动程序和内存超量使用功能在某些配置下会对MongoDB的性能产生负面影响，也不要禁用这些功能。如果禁用这些功能，管理程序可能会使用其交换空间来满足内存请求，这会对性能产生负面影响。

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，确保虚拟机保持在特定的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.如果必须手动将虚拟机迁移到另一台主机，并且虚拟机上的mongod实例是primary实例，则必须首先关闭主实例，然后关闭实例。

Follow the networking best practices for vMotion and 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集群的高可用性机制。

You can clone a virtual machine running MongoDB. You might use this function to deploy a new virtual host to add as a member of a replica set.您可以克隆运行MongoDB的虚拟机。您可以使用此功能部署新的虚拟主机，以添加为副本集的成员。

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. When memory is overcommitted, the hypervisor reallocates memory between the virtual machines. KVM's balloon driver reclaims the pages that are considered least valuable.KVM支持内存超量使用，您可以为虚拟机分配比物理机可用的更多内存。当内存超量使用时，管理程序会在虚拟机之间重新分配内存。KVM的气球驱动程序回收被认为最没有价值的页面。

The balloon driver resides inside the guest operating system. Under certain configurations, when the balloon driver expands, it can interfere with MongoDB's memory management and affect MongoDB's performance.气球驱动程序位于客户操作系统内部。在某些配置下，当气球驱动程序扩展时，它可能会干扰MongoDB的内存管理并影响MongoDB的性能。

To prevent negative performance impact from the balloon driver and memory overcommitment features, reserve the full amount of memory for the virtual machine running MongoDB. Reserving the appropriate amount of memory for the virtual machine prevents the balloon from inflating in the local operating system when there is memory pressure in the hypervisor.为了防止气球驱动程序和内存超量使用功能对性能产生负面影响，请为运行MongoDB的虚拟机保留全部内存。为虚拟机保留适量的内存可以防止在管理程序内存压力时气球在本地操作系统中膨胀。

Even though the balloon driver and memory overcommitment features can negatively affect MongoDB performance under certain configurations, do not disable these features. If you disable these features, the hypervisor may use its swap space to fulfill memory requests, which negatively affects performance.即使气球驱动程序和内存超量使用功能在某些配置下会对MongoDB的性能产生负面影响，也不要禁用这些功能。如果禁用这些功能，管理程序可能会使用其交换空间来满足内存请求，这会对性能产生负面影响。