在PayPal重构和优化高流量的API

By Nisha Bhaskaran and Jeetendra Tiwari

作者：Nisha Bhaskaran和Jeetendra Tiwari

Experimentation is increasingly becoming the standard for enabling data-driven decisions to determine the impact of every product change. It is an integral part of the product lifecycle at PayPal. Experiment Lifecycle Management and Optimization (ELMO), our in-house experimentation platform, is used to iterate and measure the impact of new product features, improved user experiences, marketing campaigns, etc.

实验正日益成为实现数据驱动决策的标准，以确定每个产品变化的影响。它是PayPal产品生命周期的一个组成部分。实验生命周期管理和优化（ELMO）是我们的内部实验平台，用于迭代和衡量新产品功能、改进用户体验和营销活动等的影响。

Client teams integrate with experimentation platform (using SDK’s) and make a service call (using evaluation APIs) for experiment evaluation in real-time based on the active experiment configuration and return the evaluated variant. Today, our focus will be on ELMO's evaluation APIs, which forms the crux of the problem statement.

客户团队与实验平台集成（使用SDK），并根据活动的实验配置实时调用服务（使用评估API）进行实验评估，并返回评估后的变量。今天，我们的重点将是ELMO的评估API，它构成了问题陈述的核心。

The evaluation APIs are critical endpoints which serve billions of requests per day from flows across multiple domains at PayPal and support different channels (such as the web and mobile). Earlier this year, we noticed the experience of using the APIs was sub-optimal, especially for our adjacencies. The SLA did not meet the standards that we set for ourselves and was also causing reliability issues for our clients. Therefore, we embarked on a journey to optimize the performance of the APIs by identifying critical bottlenecks in the flow.

评估API是关键的端点，每天为来自PayPal多个领域的流量提供数十亿次请求，并支持不同的渠道（如网络和移动）。今年早些时候，我们注意到使用API的体验是次优的，特别是对于我们的邻接点。SLA不符合我们为自己设定的标准，也给我们的客户带来了可靠性问题。因此，我们开始了通过识别流程中的关键瓶颈来优化API性能的旅程。

Defining performance

界定绩效

We defined Latency as network latency plus application request processing time. With our focus on optimizing the application request processing time, 3 parameters were chosen to define performance:

我们将Latency定义为网络延迟加上应用请求处理时间。由于我们的重点...