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指定连接选项

Overview

本节介绍Rust驾驶员中可用的MongoDB连接和身份验证选项。您可以使用连接 URI（也称为连接字符串）或在创建ClientOptions 时在Client 实例上设置字段来配置连接。

使用连接 URI

如果将连接 URI 传递给 Client::with_uri_str 方法，则可以将连接选项作为 <name>=<value> 对包含在字符串中。以下示例显示了一个连接 URI，其中包含值为 60000 的 connectTimeoutMS 选项和值为 true 的 tls 选项：

 use mongodb::Client;
   let uri = "mongodb://<hostname>:<port>/?connectTimeoutMS=60000&tls=true";
   let client = Client::with_uri_str(uri).await?;

使用 ClientOptions

您可以在 ClientOptions实例上设立连接选项，而不是将它们包含在连接 URI 中。使用 ClientOptions实例配置连接时，您可以更轻松地在运行时更改设置并在编译期间捕获错误。以下示例展示了如何使用 ClientOptions设立连接选项：

  use std::time::Duration;
  use mongodb::{Client, options::ClientOptions};
  let uri = "mongodb://<hostname>:<port>/";
  let mut client_options = ClientOptions::parse(uri).await?;
  client_options.connect_timeout = Some(Duration::from_secs(60000));
  //Set additional options on client_options here
  let client = Client::with_options(client_options)?;

连接选项

以下部分介绍了Rust驾驶员中可用的连接选项。要查看连接选项的完整列表，请访问服务器手册指南中有关连接字符串的连接字符串选项部分。

网络压缩

选项名称	接受的值	默认值	说明
compressors	以逗号分隔的字符串列表	无	Specifies compressors that the `Client` instance uses in the specified order. To learn more about network compression, see the Network Compression guide.
zlibCompressionLevel	介于 `0` 和 `9` 之间的整数	`6`	Specifies the level field of the `zlib` compression if you use that compressor. A higher level value results in more compression, which is slower. Setting a value of `0` specifies no compression, and setting a value of `9` specifies maximum compression. To learn more about network compression, see the Network Compression guide.

超时

选项名称	接受的值	默认值	说明
connectTimeoutMS	Non-negative integer	`10000` （10 秒）	指定尝试连接到服务器时传递给每个底层 TCP 流的连接超时时间（以毫秒为单位）。

服务器选择

选项名称	接受的值	默认值	说明
heartbeatFrequencyMS	大于或等于 500 的整数。	`10000` （10 秒）	指定每个监控线程在执行服务器检查之间等待的时间（以毫秒为单位）。
maxStalenessSeconds	`-1`，或任何大于或等于的整数 `90`	`-1`	Specifies the maximum lag, in seconds, behind the primary node that a secondary node can be considered for the given operation. The value of this option must be at least `90`, or the operation raises an error. A value of `-1` means there is no maximum lag.
serverSelectionTimeoutMS	Non-negative integer	`30000` （30 秒）	指定`Client`实例在尝试为操作选择服务器时在超时之前等待的时间（以毫秒为单位）。

身份验证

选项名称	接受的值	默认值	说明
authMechanism	字符串	无	指定要使用的身份验证机制。如果不指定此选项，驱动程序将使用默认的身份验证机制。要了解有关 Rust 驱动程序中身份验证的更多信息，请参阅身份验证机制指南。
authMechanismProperties	字符串	无	为`authMechanism`选项中设置的身份验证机制指定更多属性。
authSource	字符串	查看说明	Specifies the database used to authenticate. This option defaults to `admin` for SCRAM-based authentication mechanisms, `$external` for the `MONGODB-X509` mechanism, and the database name or `$external` for the `PLAIN` mechanism.
TLS	布尔	`false`	Specifies the TLS configuration for the `Client` instance to use in its connections with the server. By default, TLS is off.
tlsAllowInvalidCertificates	布尔	`false`	Specifies whether the `Client` instance returns an error if the server presents an invalid certificate. We recommend that you set this option to `true` only in testing environments to avoid creating vulnerabilities in your application.
tlsCAFile	字符串	查看说明	Specifies the path to the certificate authority (CA) file that the `Client` instance uses for TLS. If you do not specify this option, the driver uses the Mozilla root certificates from the `webpki-roots` crate.
tlsCertificateKeyFile	字符串	无	Specifies the path to the certificate file that the `Client` instance presents to the server to verify its identify. If you do not set this option, the `Client` instance does not attempt to verify its identity to the server.
tlsCertificateKeyFilePassword	字符串	无	如果密钥已加密，请指定用于解密证书文件中的私钥的密码。
tlsInsecure	布尔	`false`	Specifies whether the `Client` instance returns an error if the server presents an invalid certificate. We recommend that you set this option to `true` only in testing environments to avoid creating vulnerabilities in your application.

读取和写入操作

选项名称	接受的值	默认值	说明
directConnection	布尔	`false`	指定`Client`实例是否直接连接到单个主机，而不是发现并连接到集群中的所有服务器。
journal	布尔	`false`	请求确认操作已传播到磁盘上日志。
localThresholdMS	Non-negative integer	`15`	Specifies the amount of time in milliseconds that the average round-trip time between the driver and server can last compared to the shortest round-trip time of all the suitable servers. A value of `0` indicates that there is no latency window, so only the server with the lowest average round-trip time is eligible.
readConcernLevel	字符串	无	Specifies the default read concern for operations performed on the `Client` instance. To learn more, see Read Concern in the Server manual.
readPreference	字符串	`primary`	Specifies how the driver routes a read operation to members of a replica set. To learn more, see Read Preference in the Server manual.
readPreferenceTags	以逗号分隔的键值对列表	无	Specifies which replica set members are considered for operations. Each instance of this key is a separate tag set. The driver checks each tag set until it finds one or more servers with each tag in the set.
replicaSet	字符串	无	指定`Client`实例连接到的副本集的名称。
retryReads	布尔	`true`	指定在操作失败时客户端是否重试读取操作。
w	非负整数或字符串	无	Requests acknowledgment that the operation has propagated to a specific number or variety of servers. To learn more, see Write Concern in the Server manual.
wtimeoutMS	Non-negative integer	无超时	Specifies a time limit, in milliseconds, for the write concern. If an operation has not propagated to the requested level within the time limit, the driver raises an error.

连接池

选项名称	接受的值	默认值	说明
maxIdleTimeMS	Non-negative integer	`0`	Specifies the amount of time in milliseconds that a connection can remain idle in a connection pool before the server closes it. A value of `0` indicates that the client does not close idle connections.
maxPoolSize	Non-negative integer	`10`	Specifies the maximum number of connections that the `Client` instance can create in a connection pool for a given server. If you attempt an operation while the value of `maxPoolSize` connections are checked out, the operation waits until an in-progress operation finishes and the connection returns to the pool.
minPoolSize	Non-negative integer	`0`	Specifies the minimum number of connections available in a server's connection pool at a given time. If fewer than `minPoolSize` connections are in the pool, the server adds connections in the background up to the value of `minPoolSize`.

有关连接池的更多信息，请参阅连接池指南。

常规

选项名称	接受的值	默认值	说明
appName	字符串	无	Specifies the application name that the `Client` instance sends to the server as part of the handshake. Specifying an `appName` can help you use the server logs to determine which `Client` instance is connected to the server.

API 文档

ClientOptions有关Rust驾驶员的的更多信息，请参阅 ClientOptions 的API文档。

后退

选择连接目标

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