Lab 2 of MIT 6.828/6.S081 Fall 2019 is Simple Shell: implementing a simple shell program. This post explains the approach to the lab in detail and takes an in-depth look at the shell implementation that ships with xv6.
This post takes a detailed look at serverless architecture: its basic concepts, real products, use cases, and how it works.
This post describes how to build a personal website cleanly and cheaply on top of a range of cloud services. The cloud products involved include cloud servers, SSL, business email, object storage, CDN, cloud functions, API Gateway, and cloud monitoring.
Lab 1 of MIT 6.828/6.S081 Fall 2019 is Unix utilities: using xv6 system calls to implement tools such as sleep, pingpong, primes, find, and xargs. This post explains the approach behind each program in detail, along with how a system call flows through xv6.
This post walks through setting up the lab environment for MIT 6.828/6.S081 Fall 2019 in detail, covering the RISC-V toolchain, QEMU, and xv6. It uses macOS as the example, and the same steps apply to Linux.
In Fabric development, testing chaincode is a bit of a headache. First, in a real deployment, storage and queries in chaincode depend on the state database on the peer, so you cannot test it directly on your local machine. Second, chaincode runs inside a container, which makes it hard to get at the logs printed by your code.
My earlier posts on deploying Fabric all assumed a single machine. In a real production environment, nodes are usually spread across several physical machines depending on the use case, and the main challenge is how nodes on different hosts communicate over the network.
Adding a new organization to a Fabric network while it is running is quite involved, and there is very little material on it online. Most of what exists is based on simple examples like first-network, and adds the organization by starting a cli container. There is almost nothing aimed at real applications. This post shows how to add an organization dynamically by calling the SDK from an application.
The initial number of peers in a Fabric network is fixed when the network is created, but in real application scenarios you may need to add peers to an organization dynamically. Using balance-transfer v1.0 as an example (2 orgs, 4 peers), this post shows how to add a third peer to org1.
The organization (Org) and channel names are two fairly important configuration parameters of a Fabric network. Both are already set in the samples Fabric provides: the organizations are usually named "Org1" and "Org2", and the channel "mychannel". In real application development, however, you usually need custom organization and channel names. Here I use balance-transfer, the sample closest to a real application, to show how to set custom organization and channel names.
