uuid | 易学教程

How to create a GUID/UUID in Python

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问题 How do I create a GUID in Python that is platform independent? I hear there is a method using ActivePython on Windows but it\'s Windows only because it uses COM. Is there a method using plain Python? 回答1: The uuid module, in Python 2.5 and up, provides RFC compliant UUID generation. See the module docs and the RFC for details. [source] Docs: Python 2: http://docs.python.org/2/library/uuid.html Python 3: https://docs.python.org/3/library/uuid.html Example (working on 2 and 3): >>> import uuid

Create GUID / UUID in JavaScript?

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问题 I\'m trying to create globally-unique identifiers in JavaScript. I\'m not sure what routines are available on all browsers, how \"random\" and seeded the built-in random number generator is, etc.. The GUID / UUID should be at least 32 characters and should stay in the ASCII range to avoid trouble when passing them around. 回答1: UUIDs (Universally Unique IDentifier), also known as GUIDs (Globally Unique IDentifier), according to RFC 4122, are identifiers with a certain uniqueness guarantee. The

How unique is UUID?

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问题 How safe is it to use UUID to uniquely identify something (I\'m using it for files uploaded to the server)? As I understand it, it is based off random numbers. However, it seems to me that given enough time, it would eventually repeat it self, just by pure chance. Is there a better system or a pattern of some type to alleviate this issue? 回答1: Very safe: the annual risk of a given person being hit by a meteorite is estimated to be one chance in 17 billion, which means the probability is about

简单任务调度系统

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一概述 1 运维管理的阶段 1 人工阶段人工盯着服务器，出了问题，到机器前面，翻日志，查状态，手动操作 2 脚本阶段开始写一些自动化脚本，启动计划任务，自动启动服务，监控服务等 3 工具阶段脚本功能太弱，开发了大量工具，某种工具解决某个特定领域的问题，常用的有ansible，puppet等 4 平台阶段将工具整合，自主研发，实现标准化，实现自动化流程控制，而今，平台已经开始迈向智能化的发展方向。二 mschedule 设计 1 完整代码链接 https://gitee.com/ChangPaoZhe/mschedule 2要求 1 分发任务分发脚本到目前节点上去执行 2 控制控制并发，控制多少个节点同时执行对错误做出响应，由用户设定，最多允许失败的比例或者数量，当超过范围时，需要终止任务执行 3 能跨机房部署 4 能对作业做版本控制，这是辅助功能，可过后实现 3 项目基本概述 1 基本概述本项目的出发点，是只需要会使用shell脚本就可以了，可以通过使用shell脚本的方式来完成远程任务的下发和处理流程。 2 其他自动化工具二次开发缺点 ansible，salt等需要学习特定的内部语言，如果觉得ansible这样的工具不能满足需求，二次开发难度过高，代码量不小，本身它们开发接口不完善，而且熟悉它的叫也比较难，就算开发出来维护也难。从这些项目上二次开发

How to get a unique computer identifier in Java (like disk ID or motherboard ID)?

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I'd like to get an id unique to a computer with Java, on Windows, MacOS and, if possible, Linux. It could be a disk UUID, motherboard S/N... Runtime.getRuntime().exec can be used (it is not an applet). Ideas? It is common to use the MAC address is associated with the network card. The address is available in Java 6 through through the following API: Java 6 Docs for Hardware Address I haven't used it in Java, but for other network identification applications it has been helpful. Bartosz Firyn The problem with MAC address is that there can be many network adapters connected to the computer. Most

Leaf——美团点评分布式ID生成系统

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在复杂分布式系统中，往往需要对大量的数据和消息进行唯一标识。如在美团点评的金融、支付、餐饮、酒店、猫眼电影等产品的系统中，数据日渐增长，对数据分库分表后需要有一个唯一ID来标识一条数据或消息，数据库的自增ID显然不能满足需求；特别一点的如订单、骑手、优惠券也都需要有唯一ID做标识。此时一个能够生成全局唯一ID的系统是非常必要的。概括下来，那业务系统对ID号的要求有哪些呢？全局唯一性：不能出现重复的ID号，既然是唯一标识，这是最基本的要求。趋势递增：在MySQL InnoDB引擎中使用的是聚集索引，由于多数RDBMS使用B-tree的数据结构来存储索引数据，在主键的选择上面我们应该尽量使用有序的主键保证写入性能。单调递增：保证下一个ID一定大于上一个ID，例如事务版本号、IM增量消息、排序等特殊需求。信息安全：如果ID是连续的，恶意用户的扒取工作就非常容易做了，直接按照顺序下载指定URL即可；如果是订单号就更危险了，竞对可以直接知道我们一天的单量。所以在一些应用场景下，会需要ID无规则、不规则。上述123对应三类不同的场景，3和4需求还是互斥的，无法使用同一个方案满足。同时除了对ID号码自身的要求，业务还对ID号生成系统的可用性要求极高，想象一下，如果ID生成系统瘫痪，整个美团点评支付、优惠券发券、骑手派单等关键动作都无法执行，这就会带来一场灾难。

How good is Java's UUID.randomUUID?

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I know that randomized UUIDs have a very, very, very low probability for collision in theory, but I am wondering, in practice, how good Java's randomUUID() is in terms of not having collision? Does anybody have any experience to share? UUID uses java.security.SecureRandom , which is supposed to be "cryptographically strong". While the actual implementation is not specified and can vary between JVMs (meaning that any concrete statements made are valid only for one specific JVM), it does mandate that the output must pass a statistical random number generator test. It's always possible for an

Ubuntu18.04初始化

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Ubuntu18.04初始化更新源： sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak sudo gedit /etc/apt/sources.list deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic