关于部署

One single Orchestrator instance can simultaneously run up to 1,000 Unattended robots or up to 10,000 Attended ones. For the recommended deployment for 10K Robots, please check the information presented here.

Orchestrator 也支持多租户概念。该方法称为“共享架构”，这意味着多个租户可以共享同一数据库和同一数据库架构。每张表格中与租户相关的所有数据都可由其自己的 TenantId 作出明确定义。

逻辑分解

The UiPath Server Platform has the following logical components, grouped in three layers:

• Presentation Layer
  • Web Application
  • OData REST API Endpoints
  • Notification API
• Web Service Layer
  • REST API implementation
• Persistence Layer

  • SQL 服务器

  • Elasticsearch

    图 1. UiPath 服务器 平台图表

    

The Web Application is the visual layer of the Server Platform. The user interacts with its web pages in order to perform various actions: creating Robot groups, assigning packages to them, analyzing logs per Robot or per process, starting and stopping the Robots.

除网页外，Orchestrator 还包含一个服务层，该服务层公开主要由 OData 端点组成的 REST API。REST API由网页应用程序和代理使用。智能体是客户端计算机上一个或多个机器人的主管。

Orchestrator functionalities covered by REST API:

• Configuration - REST endpoints used to define and configure application users, permissions, Robots, assets, releases, and environments.
• 监视和通知 - REST 端点，适用于注册代理，将配置设置传递给代理以及从服务器和代理发送/接收通知。通知 API还使用 WebSocket 通信。
• 日志记录 - REST 端点，适用于记录不同的信息，例如错误、机器人发送的显式消息以及其他环境特定信息。
• Deployment - REST endpoints used by the Robots to query the package version that needs to be executed if you use the Start Job command in Orchestrator.
• Queues - REST endpoints responsible for queues and queue item management, namely adding data to the queue, obtaining a transaction from the queue, setting the status of a transaction etc.

Components of the Persistence Layer:

• SQL 服务器

  • stores the configuration of Robots, Robot groups, and associated processes, users, roles, schedules – information managed through the Web Application component.
  • manages queues and queue items.
  • optionally, stores the messages logged by the robots (in lieu of, or in addition to Elasticsearch).

• Indexer Server (Elasticsearch) whose role is to store and index the information logged by Robots. It can be disabled through configuration settings.

  备注：

  Messages logged by the robots can be stored in the SQL Server, in the Indexer Server, in both of them or in none.

索引器服务器使用 Elasticsearch（一个开源项目）全文搜索引擎。机器人记录的所有消息（使用“日志消息”或“写入行”等活动）都通过 “日志记录 REST”端点发送到索引器服务器，并在那里进行索引以供将来使用。

备注：

For a better distribution of resources, it is recommended to install the Indexer Server on a separate machine than the one on which SQL Server is installed.

On the client computer, a running process is represented in the above diagram as an Executor. There can be several business projects running simultaneously, each having a corresponding Executor. The UiPath Agent (a Windows service) is the single point of contact for all Executors, through which all messages are logged into the Orchestrator Service, which processes them further (Indexer Server or SQL Server Database or both).

机器人代表计算机名称和用户名之间的关联。它可以同时管理多名执行者。在支持同时运行多个交互式会话的系统（例如 Windows Server 2012）上，可以同时运行多个机器人，而每个机器人使用唯一的用户名在单独的 Windows 会话中运行。我们称此功能为“高密度机器人”。

The UiPath Agent is also responsible for sending the status of the Robot (e.g. SubmitHeartBeat endpoint) and downloading the required version of the package to be executed.

The communication between the Agent and Orchestrator is always initiated by the Agent. In the notification scenario, the Agent opens a WebSocket channel which is later used by Orchestrator to send commands to the Robot (Start, Stop, etc.).

负载均衡建议

我们已经使用多个网络负载均衡器（如 BIG-IP F5、Citrix NetScaler ADC、HAProxy）测试了 Orchestrator 的高可用性和灾难恢复部署。由于网络负载均衡器的深度配置因供应商而异，因此我们提出以下建议：

建议
	使用负载均衡算法，例如轮询或预测性轮询派生；
	不要使用持久性会话（也称为粘滞会话）；
	Use your preferred network load balancer in Layer 7 mode as it can interact with the Orchestrator API health checking endpoint. This API endpoint is available at https://your-orchestrator.com/api/status and returns 200 OK if the Orchestrator web app is up and running and 500 if it is not working. See Health Check Endpoints in the Orchestrator guide for details. 网络负载均衡器应每 3 至 5 秒询问一次每个 Orchestrator 服务器的 API 运行状况检查端点。