https://help.aliyun.com/document_detail/27781.html?spm=5176.7838592.6.751.qXtEjb&parentId=27278
security group
Security Group
A virtual firewall with state detection and packet filtering functions, and setting network access control for single or multiple cloud servers. Instances in the same security group can communicate with each other on the network. Instances in different security groups cannot communicate with each other on the intranet by default. You can authorize mutual access between the two security groups.
edge node
Edge Node
The network node with less intermediate links from the end user access has better responsiveness and connection speed to the end user.
massively parallel processing
Massively Parallel Processing
A distributed Shared Nothing computing architecture that uses multiple shared-nothing nodes (called compute groups in HybridDB) to compute in parallel to improve performance.
Read and write times
The number of times the application reads and writes from the database per second.
read and write volume
The amount of data the app reads and writes from the database per second.
Multiple Availability Zones
Multi-zone
A physical area composed of different Availability Zones in the same region, which can cope with failures at the Availability Zone level.
Multi-factor authentication
Multi-Factor Authentication（MFA）
A simple and effective security best practice that adds an extra layer of security beyond usernames and passwords. When MFA is enabled, when users log in to the Alibaba Cloud website, they will be asked to enter a username and password (first security factor), and then a variable verification code from their MFA device (second security factor). The combination of these multiple elements will provide a higher level of security for your account.
Distributed Service Framework
High Speed Framework
A distributed service framework for enterprise-level Internet architecture, based on a high-performance network communication framework, provides services such as service publishing and registration, service invocation, service routing, service authentication, service current limiting, service degradation and service invocation chaining Road tracking and a series of tried and tested features.
Distributed relational database service
Distributed Relational Database Service
阿里巴巴致力于解决单机数据库服务瓶颈问题而自主研发推出的分布式数据库产品。DRDS 高度兼容 MySQL 协议和语法，支持自动化水平拆分、在线平滑扩缩容、弹性扩展、透明读写分离，具备数据库全生命周期运维管控能力。DRDS 前身为淘宝 TDDL，是近千核心应用首选组件。
请参见 分布式关系型数据库服务。
服务地址
Endpoint
每个实例对应一个服务地址（Endpoint），应用程序在进行表和数据操作时需要指定服务地址。
服务降级
与服务限流相反，每一个应用会调用许多外部服务，对于这些服务配置降级规则可以实现对劣质服务的精准屏蔽，确保应用自身能够稳定运行，防止劣质的服务依赖影响应用自身的服务能力。EDAS 从响应时间维度对降级规则进行配置，帮助用户在应对流量高峰时合理地屏蔽劣质依赖。
SLF4J facade [fəˈsɑ:d]
JDBC（Java Data Base Connectivity,java数据库连接）是一种用于执行SQL语句的Java API，可以为多种关系数据库提供统一访问
OOM？ OOM，全称“Out Of Memory”，翻译成中文就是“内存用完了”，来源于java.lang.OutOfMemoryError。看下关于的官方说明： Thrown when the Java Virtual Machine cannot allocate an object because it is out of memory, and no more memory could be made available by the garbage collector. 意思就是说，当JVM因为没有足够的内存来为对象分配空间并且垃圾回收器也已经没有空间可回收时，就会抛出这个error（注：非exception，因为这个问题已经严重到不足以被应用处理）。因内存小或内存泄露或内存溢出。要dump堆的内存镜像，可以采用如下两种方式：
- 设置JVM参数-XX:+HeapDumpOnOutOfMemoryError，设定当发生OOM时自动dump出堆信息。不过该方法需要JDK5以上版本。
- 使用JDK自带的jmap命令。"jmap -dump:format=b,file=heap.bin <pid>" 其中pid可以通过jps获取dump堆内存信息后，将文件通过mat: eclipse memory analyzer, （基于eclipse RCP的内存分析工具）。详细信息参见：http://www.eclipse.org/mat/，推荐使用。