Category Archives: Computer and Internet

spring boot, docker, kubernetes

In previous post, I’ve started a working Minikube on laptop. But the deployment used a prebuilt Node.js echo server image. Here I will go through webapp built by Spring Boot, Docker image, and Kubernetes deployment/service configured via YAML. First, make … Continue reading

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taste some kubernetes, start with minikube

I was not a big fan on container technology. Well, duty calls. So I would start with tutorials and Minikube on laptop. Installation is simple. Instruction is here. One need kubectl and minikube, both is available as pre-built binary on … Continue reading

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Unicode equivalence

A few days ago I planned to write a Python script to migrate some music playlist from Mac to PC. The task was just to parse XML file and convert the content to PPL file (just plain text). How hard … Continue reading

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get some shadowsocks

Bing from Microsoft got blocked in China a few days ago. The incident seems accidental, however I still feel it is time to make some backup plan. Setup is quite easy. Get client from Shadowsocks. Pick some free server from … Continue reading

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Run multiple jobs in Flink local environment

Actually there is little reason to do this. Flink local environment is generally used to test and debug, not for scalable stream data processing. But anyway, this is the way to run multiple jobs in the local environment. First, start … Continue reading

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XXE attack and mitigation

Recently I’ve got a security violation report from Sonar. It is the XXE attack. This is indeed a scary scenario, with attacker able to access server internal file with ease. The simplest approach is to disable this feature. However in … Continue reading

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Oracle 某项目的 Database Design Guidelines

涉及用户数据的表必须有USER_ID列。主要为了sharding。相应的,表和索引基于USER_ID做partition。 使用基本构造。Heap表,B-tree索引,VARCHAR2(数据库整体应该已经是unicode编码了)。 不使用Trigger。这部分逻辑应该放在中间层。 不使用PL/SQL。同上。 数据生命周期。主要是注意数据的清理。 不使用并行操作。大多数时间并不只有一个模块在运行。 不在运行时使用DDL。DDL只在downtime执行。 可以的话使用global temporary table。 不使用foreign key。这个比较意外,主要是为了migration方便。 压缩索引。使用”COMPRESS ADVANCED LOW”。

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