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docker cp <containerId>:/file/path/within/container /host/path/target

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// Enable component-scanning and auto-configuration with @SpringBootApplication Annotation
// It combines @Configuration + @ComponentScan + @EnableAutoConfiguration
@SpringBootApplication
public class FooApplication {
  public static void main(String[] args) {
    // Bootstrap the application
    SpringApplication.run(FooApplication.class, args);
  }
}

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Backend Architectures

Twitter

ror, scala, jetty, erlang, thrift, mongrel, comet server, my-sql, memchached, varnish, kestrel(mq), starling, gizzard, cassandra, hadoop, vertica, munin, nagios, awstats

• Introduce Gizzard of Twitter - 트위터의 새로운 분산 관리 라이브러리 Gizzard를 소개합니다.
• The Architecture Twitter Uses to Deal with 150M Active Users, 300K QPS, a 22 MB/S Firehose, and Send Tweets in Under 5 Seconds
• Scaling Twitter: Making Twitter 10000 Percent Faster

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Virtual Hosts on nginx (CSC309)

When hosting our web applications, we often have one public IP address (i.e., an IP address visible to the outside world) using which we want to host multiple web apps. For example, one may wants to host three different web apps respectively for example1.com, example2.com, and example1.com/images on the same machine using a single IP address.

How can we do that? Well, the good news is Internet browsers

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System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

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Show Nth commit logs from the beginning

Example, Show first 4 commit histroies from first inital commit

it log  --pretty=oneline | tail -n 4

Output

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public class SpringContext implements ApplicationContextAware {
    /**
     * Spring应用上下文环境
     */
    private static ApplicationContext applicationContext;

    /**
     * 实现ApplicationContextAware接口的回调方法，设置上下文环境
     *
     * @param applicationContext

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    private static final String CONTENT_TYPE_ZIP = "application/x-zip-compressed";
    @PostMapping(value = "/downloadReport", produces = CONTENT_TYPE_ZIP)
    public Resource downloadReport(@RequestBody Map<String, String> map, HttpServletResponse response)  {
        String fileName = map.get("fileName");
        File file = new File("D:\\" + fileName);
        response.setHeader("Content-Disposition", "attachment; filename=info.zip");
        return new FileSystemResource(file);

    }

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import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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Bash Tricks

Remove a large number of docker containers

1. Pipe contianer ID's to text file.

docker ps -a -q > containers.txt

2. Edit containers.txt and remove the container ID's you wish to keep.