It’s well understood by now that rollups and modular blockchains present a better and a more scalable design compared to monolithic alternative Layer 1s. However, some would argue that each and every existing rollup today (ZK-based or optimistic-execution based) is in fact much less decentralized than even the least decentralized alternative Layer 1s. The core issue is that they all operate with a single sequencer — a network node core to the proper functioning of the rollups.
现在大家都明白，与单片的替代第1层相比，汇总和模块化的区块链呈现出更好、更可扩展的设计。然而，有些人认为，今天每一个现有的汇总（基于ZK或基于乐观执行）实际上比最不去中心化的替代第1层更不去中心化。 核心问题是，它们都通过一个单一的 序列器 sequencer 来运作，这是汇总正常运作的核心网络节点。
AltLayer is a protocol built to change this status quo both at the design as well as at the implementation-level. In this post, we dive deeper into the world of sequencers, the issues with centralized sequencers and the approach taken by AltLayer to build an open and decentralized sequencer network in a way that anyone wanting to launch a rollup can leverage them, thereby eliminating the need to self bootstrap a decentralized sequencer network for the rollup.
AltLayer是一个在设计和实施层面上，都是为了改善这种现状的协议。在这篇文章中，我们将深入探讨序列器的世界，中心化序列器的问题，以及AltLayer采取的方法：即建立一个开放的、去中心化的序列器网络，使任何想要启动汇总的人都可以加以利用，从而消除了为汇总而重复启动中心化序列器网络的必要。
为什么是去中心化序列 (Why Decentralized Sequencing?)
A central component to any rollup is the sequencer. Sequencers are nodes in the rollup network that are tasked with the following operations of a rollup:
任何汇总的核心组成部分都是序列器 。序列器是汇总网络中的节点，负责汇总的以下操作：
-
Aggregate transactions: Accept transactions from the end users via a mempool.
聚合交易： 通过mempool接受来自终端用户的交易。 -
Order transactions: Select transactions from the mempool and order them according to some policy.
排序交易： 从mempool中选择交易，并根据一些政策对其进行排序。 -
Execute transactions: In most rollups, the sequencer is also tasked with executing the transactions according to the underlying VM.
执行交易： 在大多数汇总中，序列器的任务也是根据底层虚拟机来执行交易。 -
Produce pre-confirmation: As finality for a rollup transaction ultimately comes from the underlying Layer 1, sequencers often produce pre-confirmation for a user transaction that allows clients and applications to proceed while waiting for finality from the Layer 1.
产生预确认： 由于汇总交易的最终结果来自底层的第1层，序列器经常为用户交易产生预确认，允许客户端和应用在等待第1层的最终结果时继续进行。 -
Send ordered transaction data to the DA Layer: As the last step, sequencer also commits the ordered transaction data to a DA layer, for example the underlying Layer 1. Once posted on Layer 1, transactions have Layer 1-level finality.
将订购的交易数据发送到DA层： 作为最后一步，序列器还将订购的交易数据提交到DA层，例如底层第1层。一旦发布到第1层，交易就具有第1层的最终(确定)性/终态。
Sequencers are therefore the heart of a rollup. Now, imagine a rollup with a single sequencer. What would happen if the sequencer were to become unavailable? Well, the network would then effectively stop processing transactions. This is not entirely a hypothetical question as there have been instances where rollups stopped processing transactions when the sequencer was down.
因此，序列器是一个汇总的核心。现在，想象一个只有一个序列器的汇总。如果序列器不可用，会发生什么？那么，网络将有效地停止处理交易。这并不完全是一个假设性的问题，因为已经有实例表明，当序列器出现故障时，汇总系统停止处理交易。
While one could argue that even when a sequencer goes down, the network is still operational as users could instead send their Layer 2 transaction directly to Layer 1. However, those transactions can take up to 24 hours to be considered final and will cost the same fees as the underlying Layer 1 and hence would result in poor user experience. Also, a 24 hour delay may not be ideal for time-sensitive transactions like liquidation of a debt position.
虽然人们可以说，即使一个序列器发生故障，网络仍然可以运行，因为用户可以代替他们把第2层的交易直接发送到第1层。然而，这些交易可能需要长达24小时才能被最终确认，并将花费与底层第1层相同的费用，因此会导致用户体验不佳。另外，24小时的延迟对于像清算债务头寸这样的时间敏感型交易，可能并不理想。
More generally, a centralized sequencer may:
更为普遍的是，中心化序列器可能：
- Censor user transactions
审查用户交易 - Become a choke-point or in the worst-case could go completely unavailable
成为一个阻塞点，或者在最坏的情况下可能完全不可用 - Extract excessive rent
提取过多的租金 - Frontrun user transactions or more broadly create bad MEV and adversely affect users
抢跑用户交易或更广泛地创造坏的MEV，并对用户产生不利影响
It is therefore imperative to decentralize the sequencer. Unfortunately, none of the live rollups have decentralized sequencing enabled today.
因此，当务之急是将序列器去中心化。不幸的是，今天没有一个实时启用了去中心化序列器。
对AltLayer的简要介绍 (Brief Intro to AltLayer)
AltLayer offers Rollup-as-a-Service (RaaS) solutions that enable users to launch highly scalable application-tailored rollups quickly and reliably. The RaaS offering comes in the form of a no-code dashboard that allows not only developers but also those with limited or no coding experience to spin up a customized rollup within 2 mins through a few simple clicks.
AltLayer提供汇总即服务(RaaS)解决方案，使用户能够快速、可靠地启动高度可扩展的应用定制汇总。该RaaS产品以无代码仪表盘的形式出现，不仅使得开发人员，而且使得那些编码经验有限或没有编码经验的人，通过几个简单的点击，在2分钟内启动一个定制的汇总。
AltLayer’s RaaS offering can save significant capital, manpower resources and years of development work for application teams while encouraging innovation and rapid experimentation.
AltLayer的RaaS产品可以为应用团队节省大量资金、人力资源和多年的开发工作，同时鼓励创新和快速实验。
With AltLayer, decentralized sequencing is baked into the RaaS design and therefore the service entirely eliminates the issues prevalent in rollups with centralized sequencers.
在AltLayer中，去中心化序列被植入RaaS设计中，因此该服务完全消除了中心化序列器在汇总中普遍存在的问题。
Watch out for an upcoming post, which details how our multi-sequencers are designed, and how they create a more decentralized infrastructure for rollups! Coming soon!
请注意即将发布的一篇文章，其中详细介绍了我们的多序列器是如何设计的，以及它们如何为汇总创造一个更加去中心化基础设施！即将发布!
