diff复制代码- request_streaming
- response_streaming

diff复制代码- request_deserializer
- response_serializer

diff复制代码- unary_unary
- unary_stream

diff复制代码- stream_unary
- stream_stream

ini复制代码next_handler = continuation(handler_call_details)

bash复制代码upstream lbs {   
    server 192.168.0.106:8080; #节点一
    server 192.168.0.106:8081; #节点二
}

location /api/ {    
    proxy_pass http://lbs;   
    proxy_redirect default;}

复制代码可以用spring boot或者node开发一个应用，对外提供一个接口。
这个接口的主要功能就是用户访问之后 返回当前这个机器的ip跟端口，
这样我们或许做负载均衡测试的时候，就可以知道我们当前访问的是哪个机器。

ini复制代码//案例upstream lbs {   
   server 192.168.159.133:8080 weight=5;   
   server 192.168.159.133:8081 weight=10; 
}

ini复制代码//案例upstream lbs {   
   server 192.168.159.133:8080 weight=5;   
   server 192.168.159.133:8081 weight=10; 
}

ini复制代码upstream lbs {   
   ip_hash;   
   server 192.168.159.133:8080;   
   server 192.168.159.133:8081;
}

ini复制代码upstream lbs {   
     ip_hash;   
     server 192.168.159.133:8080 down;   
     server 192.168.159.133:8081;
}

ini复制代码upstream lbs {   
     ip_hash;   
     server 192.168.159.133:8080 backup;   
     server 192.168.159.133:8081;
 }

复制代码Nginx配置成系统服务
Nginx命令配置到系统环境

bash复制代码vim /usr/lib/systemd/system/nginx.service

ini复制代码[Unit]
Description=nginx web service
Documentation=http://nginx.org/en/docs/
After=network.target
​
[Service]
Type=forking
PIDFile=/usr/local/nginx/logs/nginx.pid
ExecStartPre=/usr/local/nginx/sbin/nginx -t -c /usr/local/nginx/conf/nginx.conf
ExecStart=/usr/local/nginx/sbin/nginx
ExecReload=/usr/local/nginx/sbin/nginx -s reload
ExecStop=/usr/local/nginx/sbin/nginx -s stop
PrivateTmp=true
​
[Install]
WantedBy=default.target

bash复制代码chmod 755 /usr/lib/systemd/system/nginx.service

makefile复制代码启动: systemctl start nginx
停止: systemctl stop nginx
重启: systemctl restart nginx
重新加载配置文件: systemctl reload nginx
查看nginx状态: systemctl status nginx
开机启动: systemctl enable nginx

bash复制代码/usr/local/nginx/sbin/nginx -V
cd /usr/local/nginx/sbin  nginx -V
如何优化？？？

ruby复制代码vim /etc/profile
在最后一行添加
export PATH=$PATH:/usr/local/nginx/sbin

bash复制代码source /etc/profile

复制代码nginx -V

perl复制代码listen 127.0.0.1:8000; // listen localhost:8000 监听指定的IP和端口
listen 127.0.0.1;   监听指定IP的所有端口
listen 8000;    监听指定端口上的连接
listen *:8000;  监听指定端口上的连接

ini复制代码server{
        listen 8080;
        server_name 127.0.0.1;
        location /{
                root html;
                index index.html;
        }
}
server{
        listen 8080 default_server;
        server_name localhost;
        default_type text/plain;
        return 444 'This is a error request';
}

复制代码精确匹配
通配符匹配
正则表达式匹配

ini复制代码server {
    listen 80;
    server_name www.baidu.com www.jd.com;
    ...
}

复制代码hosts是一个没有扩展名的系统文件，可以用记事本等工具打开，其作用就是将一些常用的网址域名与其对应的IP地址建立一个关联“数据库”，当用户在浏览器中输入一个需要登录的网址时，系统会首先自动从hosts文件中寻找对应的IP地址，一旦找到，系统会立即打开对应网页，如果没有找到，则系统会再将网址提交DNS域名解析服务器进行IP地址的解析。

bash复制代码vim /etc/hosts
127.0.0.1 www.baidu.com 
127.0.0.1 www.jd.com

ini复制代码server {
    listen 80;
    server_name  *.baidu.com    www.jd.*;
    # www.baidu.com abc.baidu.com  www.jd.cn www.jd.com
    ...
}

arduino复制代码server {
    listen 80;
    server_name  www.*.cn www.jd.c*
    ...
}

bash复制代码server{
        listen 80;
        server_name ~^www.(\w+).com$;
        default_type text/plain;
        return 200 $1  $2 ..;
}
注意 ~后面不能加空格，括号可以取值

arduino复制代码server{
    listen 80;
    server_name ~^www.\w+.com$;
    default_type text/plain;
    return 200 'regex_success';
}
​
server{
    listen 80;
    server_name www.baidu.*;
    default_type text/plain;
    return 200 'wildcard_after_success';
}
​
server{
    listen 80;
    server_name *.baidu.com;
    default_type text/plain;
    return 200 'wildcard_before_success';
}
​
server{
    listen 80;
    server_name www.baidu.com;
    default_type text/plain;
    return 200 'exact_success';
}
​
server{
    listen 80 default_server;
    server_name _;
    default_type text/plain;
    return 444 'default_server not found server';
}

vbscript复制代码exact_success
wildcard_before_success
wildcard_after_success
regex_success
default_server not found server!!

makefile复制代码No1:准确匹配server_name
​
No2:通配符在开始时匹配server_name成功
​
No3:通配符在结束时匹配server_name成功
​
No4:正则表达式匹配server_name成功
​
No5:被默认的default_server处理，如果没有指定默认找第一个server

ini复制代码server{
    listen 80;
    server_name localhost;
    location / {
    
    }
    location /abc{
    
    }
    ...
}

arduino复制代码server {
    listen 80;
    server_name 127.0.0.1;
    location /abc{
        default_type text/plain;
        return 200 "access success";
    }
}
以下访问都是正确的
http://192.168.200.133/abc
http://192.168.200.133/abc?p1=TOM
http://192.168.200.133/abc/
http://192.168.200.133/abcdef

arduino复制代码server {
        listen 80;
        server_name 127.0.0.1;
        location =/abc{
                default_type text/plain;
                return 200 "access success";
        }
}
可以匹配到
http://192.168.200.133/abc
http://192.168.200.133/abc?p1=TOM
匹配不到
http://192.168.200.133/abc/
http://192.168.200.133/abcdef

arduino复制代码server {
        listen 80;
        server_name 127.0.0.1;
        location ~^/abc\w${
                default_type text/plain;
                return 200 "access success";
        }
}
server {
        listen 80;
        server_name 127.0.0.1;
        location ~*^/abc\w${
                default_type text/plain;
                return 200 "access success";
        }
}

arduino复制代码 server {
        listen 80;
        server_name 127.0.0.1;
        location ^~/abc{
                default_type text/plain;
                return 200 "access success";
        }
}

bash复制代码location /images {
    root /usr/local/nginx/html;
}

arduino复制代码http://192.168.200.133/images/mv.png

bash复制代码location /images {
    alias /usr/local/nginx/html;
}

bash复制代码root的处理结果是: root路径+location路径
/usr/local/nginx/html/images/mv.png
alias的处理结果是:使用alias路径替换location路径
/usr/local/nginx/html/images

bash复制代码location /images {
    alias /usr/local/nginx/html/images;
}

bash复制代码location /images/ {
    alias /usr/local/nginx/html/images;
}

bash复制代码root的处理结果是: root路径+location路径
alias的处理结果是:使用alias路径替换location路径
alias是一个目录别名的定义，root则是最上层目录的含义。
如果location路径是以/结尾,则alias也必须是以/结尾，root没有要求

perl复制代码location / {
    root /usr/local/nginx/html;
    index index.html index.htm;
}
访问该location的时候，可以通过 http://ip:port/，地址后面如果不添加任何内容，则默认依次访问index.html和index.htm，找到第一个来进行返回

arduino复制代码server {
    error_page 404 http://www.baidu.com;
}

ini复制代码server{
    error_page 404 /50x.html;
    error_page 500 502 503 504 /50x.html;
    location =/50x.html{
        root html;
    }
}

kotlin复制代码server{
    error_page 404 @jump_to_error;
    location @jump_to_error {
        default_type text/plain;
        return 404 'Not Found Page...';
    }
}

ini复制代码server{
    error_page 404 =200 /50x.html;
    location =/50x.html{
        root html;
    }
}
这样的话，当返回404找不到对应的资源的时候，在浏览器上可以看到，最终返回的状态码是200，这块需要注意下，编写error_page后面的内容，404后面需要加空格，200前面不能加空格

bash复制代码-output-http value  //转发进入的请求到一个http地址上
        Forwards incoming requests to given http address.
                # Redirect all incoming requests to staging.com address 
                gor --input-raw :80 --output-http http://staging.com
  -output-http-elasticsearch string  //把请求和响应状态发送到 ElasticSearch
        Send request and response stats to ElasticSearch:
                gor --input-raw :8080 --output-http staging.com --output-http-elasticsearch 'es_host:api_port/index_name'
  -output-http-queue-len int //http输出队列大小
        Number of requests that can be queued for output, if all workers are busy. default = 1000 (default 1000)
  -output-http-redirects int  // 设置多少次重定向被允许，默认忽略
        Enable how often redirects should be followed.
  -output-http-response-buffer value  //最大接收响应大小(缓冲区)
        HTTP response buffer size, all data after this size will be discarded.
  -output-http-skip-verify
        Don't verify hostname on TLS secure connection.
  -output-http-stats  //每5秒钟输出一次输出队列的状态
        Report http output queue stats to console every N milliseconds. See output-http-stats-ms
  -output-http-stats-ms int
        Report http output queue stats to console every N milliseconds. default: 5000 (default 5000)
  -output-http-timeout duration  //指定 http 的 request/response 超时时间，默认是 5 秒 
        Specify HTTP request/response timeout. By default 5s. Example: --output-http-timeout 30s (default 5s)
  -output-http-track-response
        If turned on, HTTP output responses will be set to all outputs like stdout, file and etc.
  -output-http-worker-timeout duration
        Duration to rollback idle workers. (default 2s)
  -output-http-workers int  //gor默认是动态的扩展工作者数量，你也可以指定固定数量的工作者
        Gor uses dynamic worker scaling. Enter a number to set a maximum number of workers. default = 0 = unlimited.
  -output-http-workers-min int
        Gor uses dynamic worker scaling. Enter a number to set a minimum number of workers. default = 1.

go复制代码// NewHTTPOutput constructor for HTTPOutput
// Initialize workers
func NewHTTPOutput(address string, config *HTTPOutputConfig) PluginReadWriter {
	o := new(HTTPOutput)
	var err error
	config.url, err = url.Parse(address)
	if err != nil {
		log.Fatal(fmt.Sprintf("[OUTPUT-HTTP] parse HTTP output URL error[%q]", err))
	}
	if config.url.Scheme == "" {
		config.url.Scheme = "http"
	}
	config.rawURL = config.url.String()
	if config.Timeout < time.Millisecond*100 {
		config.Timeout = time.Second
	}
	if config.BufferSize <= 0 {
		config.BufferSize = 100 * 1024 // 100kb
	}
	if config.WorkersMin <= 0 {
		config.WorkersMin = 1
	}
	if config.WorkersMin > 1000 {
		config.WorkersMin = 1000
	}
	if config.WorkersMax <= 0 {
		config.WorkersMax = math.MaxInt32 // idealy so large
	}
	if config.WorkersMax < config.WorkersMin {
		config.WorkersMax = config.WorkersMin
	}
	if config.QueueLen <= 0 {
		config.QueueLen = 1000
	}
	if config.RedirectLimit < 0 {
		config.RedirectLimit = 0
	}
	if config.WorkerTimeout <= 0 {
		config.WorkerTimeout = time.Second * 2
	}
	o.config = config
	o.stop = make(chan bool)
	//是否收集统计信息，统计输出间隔是多少
	if o.config.Stats {
		o.queueStats = NewGorStat("output_http", o.config.StatsMs)
	}

	o.queue = make(chan *Message, o.config.QueueLen)
	if o.config.TrackResponses {
		o.responses = make(chan *response, o.config.QueueLen)
	}
	// it should not be buffered to avoid races
	o.stopWorker = make(chan struct{})

	if o.config.ElasticSearch != "" {
		o.elasticSearch = new(ESPlugin)
		o.elasticSearch.Init(o.config.ElasticSearch)
	}
	o.client = NewHTTPClient(o.config)
	o.activeWorkers += int32(o.config.WorkersMin)
	for i := 0; i < o.config.WorkersMin; i++ {
		go o.startWorker()
	}
	go o.workerMaster()
	return o
}

go复制代码o.client = NewHTTPClient(o.config)
	o.activeWorkers += int32(o.config.WorkersMin)
	for i := 0; i < o.config.WorkersMin; i++ {
		go o.startWorker()
	}

go复制代码func (o *HTTPOutput) startWorker() {
	for {
		select {
		case <-o.stopWorker:
			return
		case msg := <-o.queue:
			o.sendRequest(o.client, msg)
		}
	}
}

go复制代码func (o *HTTPOutput) sendRequest(client *HTTPClient, msg *Message) {
	if !isRequestPayload(msg.Meta) {
		return
	}

	uuid := payloadID(msg.Meta)
	start := time.Now()
	resp, err := client.Send(msg.Data)
	stop := time.Now()

	if err != nil {
		Debug(1, fmt.Sprintf("[HTTP-OUTPUT] error when sending: %q", err))
		return
	}
	if resp == nil {
		return
	}

	if o.config.TrackResponses {
		o.responses <- &response{resp, uuid, start.UnixNano(), stop.UnixNano() - start.UnixNano()}
	}

	if o.elasticSearch != nil {
		o.elasticSearch.ResponseAnalyze(msg.Data, resp, start, stop)
	}
}

go复制代码// Send sends an http request using client create by NewHTTPClient
func (c *HTTPClient) Send(data []byte) ([]byte, error) {
	var req *http.Request
	var resp *http.Response
	var err error

	req, err = http.ReadRequest(bufio.NewReader(bytes.NewReader(data)))
	if err != nil {
		return nil, err
	}
	// we don't send CONNECT or OPTIONS request
	if req.Method == http.MethodConnect {
		return nil, nil
	}

	if !c.config.OriginalHost {
		req.Host = c.config.url.Host
	}

	// fix #862
	if c.config.url.Path == "" && c.config.url.RawQuery == "" {
		req.URL.Scheme = c.config.url.Scheme
		req.URL.Host = c.config.url.Host
	} else {
		req.URL = c.config.url
	}

	// force connection to not be closed, which can affect the global client
	req.Close = false
	// it's an error if this is not equal to empty string
	req.RequestURI = ""

	resp, err = c.Client.Do(req)
	if err != nil {
		return nil, err
	}
	if c.config.TrackResponses {
		return httputil.DumpResponse(resp, true)
	}
	_ = resp.Body.Close()
	return nil, nil

makefile复制代码输入: 
    tree = [7,4,3,null,null,6,19], target = 3

输出: 
    3

解释: 
    上图画出了树 original 和 cloned。target 节点在树 original 中，用绿色标记。答案是树 cloned 中的黄颜色的节点（其他示例类似）。

ini复制代码输入: 
    tree = [7], target =  7

输出: 
    7

csharp复制代码输入: 
    tree = [8,null,6,null,5,null,4,null,3,null,2,null,1], target = 4

输出: 
    4

ini复制代码输入: 
    tree = [1,2,3,4,5,6,7,8,9,10], target = 5

输出: 
    5

ini复制代码输入: 
    tree = [1,2,null,3], target = 2

输出: 
    2

java复制代码/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */

class Solution {
    public final TreeNode getTargetCopy(final TreeNode original, final TreeNode cloned, final TreeNode target) {
        Deque<TreeNode> stack      = new LinkedList<>();
        TreeNode        node       = original;
        TreeNode        clonedNode = cloned;
        while (node != null || !stack.isEmpty()) {
            if (node != null) {
                if (node == target) {
                    return clonedNode;
                }
                stack.push(clonedNode);
                stack.push(node);
                node = node.left;
                clonedNode = clonedNode.left;
            } else {
                node = stack.pop().right;
                clonedNode = stack.pop().right;
            }
        }
        return null;
    }
}

java复制代码/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */

class Solution {
    public final TreeNode getTargetCopy(final TreeNode original, final TreeNode cloned, final TreeNode target) {
        if (cloned == null
                || original == target) {
            return cloned;
        }
        TreeNode ans = getTargetCopy(original.left, cloned.left, target);
        if (ans == null) {
            ans = getTargetCopy(original.right, cloned.right, target);
        }
        return ans;
    }
}

cpp复制代码/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */

class Solution {
public:
    TreeNode* getTargetCopy(TreeNode* original, TreeNode* cloned, TreeNode* target) {
        if (cloned == nullptr
            || original == target) {
            return cloned;
        }
        TreeNode* ans = getTargetCopy(original->left, cloned->left, target);
        if (ans == nullptr) {
            ans = getTargetCopy(original->right, cloned->right, target);
        }
        return ans;
    }
};

python复制代码# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def getTargetCopy(self, original: TreeNode, cloned: TreeNode, target: TreeNode) -> TreeNode:
        if cloned is None or original == target:
            return cloned
        ans = self.getTargetCopy(original.left, cloned.left, target)
        if ans is None:
            ans = self.getTargetCopy(original.right, cloned.right, target)
        return ans

js复制代码go get github.com/asdine/storm/v3

js复制代码import "github.com/asdine/storm/v3"

js复制代码//db, err := storm.Open("my.db", storm.BoltOptions(0600, &bolt.Options{Timeout: 1 * time.Second}))

js复制代码var (
   db *storm.DB
   err error
)

func init() {
   db, err = storm.Open("my.db")
   if err != nil {
      panic(err)
   }
}

js复制代码type User struct {
   ID        int
   Group     string `storm:"index"`
   Email     string `storm:"unique"`
   Name      string
   Age       int       `storm:"index"`
   CreatedAt time.Time `storm:"index"`
}

js复制代码user := User{
   ID:    1,
   Group: "frontend",
   Email: "zhangsan@libaigo.com",
   Name:  "zhangsan",
   Age:   21,
   CreatedAt:time.Now(),
}
user2 := User{
   ID:    2,
   Group: "frontend",
   Email: "lisi@libaigo.com",
   Name:  "lisi",
   Age:   32,
   CreatedAt:time.Now(),
}
user3 := User{
   ID:    3,
   Group: "backend",
   Email: "zhaowu@libaigo.com",
   Name:  "zhaowu",
   Age:   31,
   CreatedAt:time.Now(),
}

_ = db.Save(&user)
_ = db.Save(&user2)
_ = db.Save(&user3)

js复制代码var u User
_ = db.One("Name", "zhangsan", &u)
fmt.Println("单条",u)

var u2 []User
_ = db.Find("Group", "frontend", &u2)
fmt.Println("多条",u2)

var u3 []User
_ = db.All(&u3)
fmt.Println("全部",u3)

var u4 []User
_ = db.Range("Age", 30, 40, &u4)
fmt.Println(u4)

var u5 []User
_ = db.Prefix("Name", "z", &u5)
fmt.Println(u5)

js复制代码var u6 []User
_ = db.Find("Group", "frontend", &u6, storm.Skip(10))
_ = db.Find("Group", "frontend", &u6, storm.Limit(10))
_ = db.Find("Group", "frontend", &u6, storm.Reverse())
_ = db.Find("Group", "frontend", &u6, storm.Limit(10), storm.Skip(10), storm.Reverse())

_ = db.All(&u6, storm.Limit(10), storm.Skip(10), storm.Reverse())
_ = db.AllByIndex("CreatedAt", &u6, storm.Limit(10), storm.Skip(10), storm.Reverse())
_ = db.Range("Age", 10, 21, &u6, storm.Limit(10), storm.Skip(10), storm.Reverse())

js复制代码_ = db.Update(&User{ID:1,Name:"zhangsan",Age:19})
_ = db.UpdateField(&User{ID:3},"Age", 26)

js复制代码q.Eq("Name", "lisi")
q.Gt("Age", 7)
q.Lte("Age", 77)
q.Re("Name", "^z")
q.In("Group", []string{"frontend", "backend"})

//查询例子
query := db.Select(q.Gte("Age", 7), q.Lte("Age", 77)).
   Limit(10).Skip(0).OrderBy("Age").Reverse()
var u8 []User
err = query.Find(&u8)
fmt.Println(u8)

js复制代码_  = db.DeleteStruct(&user)

err := db.Drop(&User{})
fmt.Println(err)

err = db.Init(&User{})

err = db.ReIndex(&User{})

c复制代码/*
 * 如果 key 已经过期，那么将它删除，否则，不做动作。
 *
 * key 没有过期时间、服务器正在载入或 key 未过期时，返回 0 
 * key 已过期，那么返回正数值
 */
int expireIfNeeded(redisDb *db, robj *key) {
    // 取出 key 的过期时间
    long long when = getExpire(db,key);

    // key 没有过期时间，直接返回
    if (when < 0) return 0; /* No expire for this key */

    /* Don't expire anything while loading. It will be done later. */
    // 不要在服务器载入数据时执行过期
    if (server.loading) return 0;

    /* If we are running in the context of a slave, return ASAP:
     * the slave key expiration is controlled by the master that will
     * send us synthesized DEL operations for expired keys.
     *
     * Still we try to return the right information to the caller, 
     * that is, 0 if we think the key should be still valid, 1 if
     * we think the key is expired at this time. */
    // 如果服务器作为附属节点运行，那么直接返回
    // 因为附属节点的过期是由主节点通过发送 DEL 命令来删除的
    // 不必自主删除
    if (server.masterhost != NULL) {
        // 返回一个理论上正确的值，但不执行实际的删除操作
        return mstime() > when;
    }

    /* Return when this key has not expired */
    // 未过期
    if (mstime() <= when) return 0;

    /* Delete the key */
    server.stat_expiredkeys++;

    // 传播过期命令
    propagateExpire(db,key);

    // 从数据库中删除 key
    return dbDelete(db,key);
}

go复制代码// demo.go
var limit int
flag.IntVar(&limit, "limit", 10, "the max number of results")
flag.Parse()
fmt.Println("the limit is", limit)

// 执行结果
$ go run demo.go 
the limit is 10
$ go run demo.go -limit 100
the limit is 100

go复制代码package main

import (
  "fmt"
  "strings"

  "github.com/spf13/cobra"
)

func main() {
  var echoTimes int

  var cmdPrint = &cobra.Command{
    Use:   "print [string to print]",
    Short: "Print anything to the screen",
    Long: `print is for printing anything back to the screen.
For many years people have printed back to the screen.`,
    Args: cobra.MinimumNArgs(1),
    Run: func(cmd *cobra.Command, args []string) {
      fmt.Println("Print: " + strings.Join(args, " "))
    },
  }

  var cmdEcho = &cobra.Command{
    Use:   "echo [string to echo]",
    Short: "Echo anything to the screen",
    Long: `echo is for echoing anything back.
Echo works a lot like print, except it has a child command.`,
    Args: cobra.MinimumNArgs(1),
    Run: func(cmd *cobra.Command, args []string) {
      fmt.Println("Echo: " + strings.Join(args, " "))
    },
  }

  var cmdTimes = &cobra.Command{
    Use:   "times [string to echo]",
    Short: "Echo anything to the screen more times",
    Long: `echo things multiple times back to the user by providing
a count and a string.`,
    Args: cobra.MinimumNArgs(1),
    Run: func(cmd *cobra.Command, args []string) {
      for i := 0; i < echoTimes; i++ {
        fmt.Println("Echo: " + strings.Join(args, " "))
      }
    },
  }

  cmdTimes.Flags().IntVarP(&echoTimes, "times", "t", 1, "times to echo the input")

  var rootCmd = &cobra.Command{Use: "app"}
  rootCmd.AddCommand(cmdPrint, cmdEcho)
  cmdEcho.AddCommand(cmdTimes)
  rootCmd.Execute()
}

shell复制代码$ go run cobra.go echo times hello --times 3
Echo: hello
Echo: hello
Echo: hello

csharp复制代码// 为什么我不能写成下面这样呢？
func times(){
    cobra.IntVarP(&echoTimes, "times", "t", 1, "times to echo the input")
    cobra.Parse()
}

ruby复制代码$ cmd arg1 arg2 arg3

bash复制代码flag.IntVar(&limit, "limit", 10, "the max number of results")

// 变量绑定，当在命令行中指定 -limit 100 的时候，这意味着我们是把 100 这个值，赋予变量 limit

go复制代码// 不带有横线的参数也可以实现关联变量或函数
for _, arg := range os.Args{
    switch arg{
        case "limit": // 设置 limit 变量
        case "scan": // 调用 scan 函数
    }
}

csharp复制代码func command(){
    // 定义 flags
    // 调用 Parse 函数
}

shell复制代码$ app echo times hello --times 3

shell复制代码$ app echo --color red times hello --times 3

ini复制代码# 关联到 echoTimes 函数
"echo times" => echoTimes

# 调整子命令只是改一下这个映射而已
"times echo" => echoTimes

go复制代码package main

import (
  "fmt"
  "strings"

  "github.com/shafreeck/cortana"
)

func print() {
  cortana.Title("Print anything to the screen")
  cortana.Description(`print is for printing anything back to the screen.
For many years people have printed back to the screen.`)
  args := struct {
    Texts []string `cortana:"texts"`
  }{}

  cortana.Parse(&args)
  fmt.Println(strings.Join(args.Texts, " "))
}

func echo() {
  cortana.Title("Echo anything to the screen")
  cortana.Description(`echo is for echoing anything back. 
Echo works a lot like print, except it has a child command.`)
  args := struct {
    Texts []string `cortana:"texts"`
  }{}

  cortana.Parse(&args)
  fmt.Println(strings.Join(args.Texts, " "))
}

func echoTimes() {
  cortana.Title("Echo anything to the screen more times")
  cortana.Description(`echo things multiple times back to the user by providing
  a count and a string.`)
  args := struct {
    Times int      `cortana:"--times, -t, 1, times to echo the input"`
    Texts []string `cortana:"texts"`
  }{}
  cortana.Parse(&args)

  for i := 0; i < args.Times; i++ {
    fmt.Println(strings.Join(args.Texts, " "))
  }
}

func main() {
  cortana.AddCommand("print", print, "print anything to the screen")
  cortana.AddCommand("echo", echo, "echo anything to the screen")
  cortana.AddCommand("echo times", echoTimes, "echo anything to the screen more times")
  cortana.Launch()
}

bash复制代码# 不加任何子命令，输出自动生成的帮助信息
$ ./app
Available commands:

print                         print anything to the screen
echo                          echo anything to the screen
echo times                    echo anything to the screen more times

# 默认启用 -h, --help 选项，开发者无需做任何事情
$ ./app print -h
Print anything to the screen

print is for printing anything back to the screen.
For many years people have printed back to the screen.

Usage: print [texts...]

  -h, --help                     help for the command
  
# echo 任意内容
$ ./app echo hello world
 hello world
 
# echo 任意次数
$ ./app echo times hello world --times 3
 hello world
 hello world
 hello world

# --times 参数可以在任意位置
$ ./app echo --times 3 times hello world
 hello world
 hello world
 hello world

go复制代码args := struct {
    Times int      `cortana:"--times, -t, 1, times to echo the input"`
    Texts []string `cortana:"texts"`
}{}

bash复制代码cortana.AddCommand("echo", echo, "echo anything to the screen")

bash复制代码// 定义 print 为 echo 命令的别名
cortana.Alias("print", "echo")

bash复制代码$ ./app print -h
Echo anything to the screen

echo is for echoing anything back. 
Echo works a lot like print, except it has a child command.

Available commands:

echo times                    echo anything to the screen more times


Usage: echo [texts...]

  -h, --help                     help for the command

shell复制代码cortana.Alias("three", "echo times --times 3")

# three 是 echo times --times 3 的别名
$ ./app three hello world
 hello world
 hello world
 hello world

bash复制代码cortana.Use(cortana.HelpFlag("--usage", "-u"))

# 自定义 --usage 来打印帮助信息
$ ./app echo --usage
Echo anything to the screen

echo is for echoing anything back. 
Echo works a lot like print, except it has a child command.

Available commands:

echo times                    echo anything to the screen more times


Usage: echo [texts...]

  -u, --usage                    help for the command

bash复制代码cortana.Alias("help", "--help")

// 通过别名，实现 help 命令，用于打印任意子命令的帮助信息
$ ./app help echo times
Echo anything to the screen more times

echo things multiple times back to the user by providing
        a count and a string.

Usage: echo times [options] [texts...]

  -t, --times <times>            times to echo the input. (default=1)
  -h, --help                     help for the command

复制代码默认值 < 配置文件 < 环境变量 < 参数

less复制代码cortana.AddConfig("app.json", cortana.UnmarshalFunc(json.Unmarshal))

go复制代码func main(){
  args := struct {
    Version bool `cortana:"--version, -v, , print the command version"`
  }{}
  cortana.Parse(&args)
  if args.Version {
    fmt.Println("v0.1.1")
        return
  }
    // ...
}

$ ./app --version
v0.1.1

erlang复制代码1.配置主库DG参数，备库根据主库的PFILE,设置参数值,生成备库SPFILE.
2.配置hosts文件，配置TNS，配置静态监听，添加standby log文件.
3.拷贝主库的密码文件至备库，备库创建PFILE中不存在的目录.
4.把备库启动到nomount状态.
5.RMAN同时连接主库与备库，执行duplicate命令.

bash复制代码./AllOracleSilent.sh -i 192.168.56.120 -d 11g -n orcl -o orcl -b /u01/app -s AL32UTF8

bash复制代码./AllOracleSilent.sh -i 192.168.56.121 -d 11g -w Y -n orcl_stby -o orcl -b /u01/app -s AL32UTF8

bash复制代码cat <<EOF >> /etc/hosts
##FOR DG BEGIN
192.168.56.121 orcl_stby
##FOR DG END
EOF

bash复制代码cat <<EOF >> /etc/hosts
##FOR DG BEGIN
192.168.56.120 orcl
##FOR DG END
EOF

bash复制代码##listener.ora
su - oracle -c "cat <<EOF >> /u01/app/oracle/product/11.2.0/db/network/admin/listener.ora
##FOR DG BEGIN
SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (GLOBAL_DBNAME = orcl)
      (ORACLE_HOME = /u01/app/oracle/product/11.2.0/db)
      (SID_NAME = orcl)
    )
  )
##FOR DG END
EOF"

##重启监听
su - oracle -c "lsnrctl stop"
su - oracle -c "lsnrctl start"

##tnsnames.ora
su - oracle -c "cat <<EOF >> /u01/app/oracle/product/11.2.0/db/network/admin/tnsnames.ora
##FOR DG BEGIN
ORCL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = orcl)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = orcl)
    )
  )

ORCL_STBY =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = orcl_stby)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = orcl_stby)
    )
  )
##FOR DG BEGIN
EOF"

sql复制代码select log_mode,force_logging from gv$database;

LOG_MODE     FOR
------------ ---
NOARCHIVELOG NO

--开启归档模式
shutdown immediate
startup mount
alter database archivelog;
alter database open;

--开启强制日志模式
alter database force logging;

--查看数据文件路径是否一致，OMF参数建议关闭
select name from v$datafile;
show parameter db_create_file_dest
alter system reset db_create_file_dest;
--NOTES:如果数据文件路径不一致，duplicate将失败。

--设置DG参数
ALTER SYSTEM SET LOG_ARCHIVE_CONFIG='DG_CONFIG=(ORCL,ORCL_STBY)';
ALTER SYSTEM SET LOG_ARCHIVE_DEST_1='LOCATION=/archivelog VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=ORCL';
ALTER SYSTEM SET LOG_ARCHIVE_DEST_2='SERVICE=orcl_stby ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORCL_STBY';
ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=DEFER;
ALTER SYSTEM SET LOG_ARCHIVE_FORMAT='%t_%s_%r.arc' SCOPE=SPFILE;
ALTER SYSTEM SET LOG_ARCHIVE_MAX_PROCESSES=4;
ALTER SYSTEM SET REMOTE_LOGIN_PASSWORDFILE=EXCLUSIVE SCOPE=SPFILE;
ALTER SYSTEM SET FAL_SERVER=ORCL_STBY;
ALTER SYSTEM SET FAL_CLIENT=ORCL;
ALTER SYSTEM SET DB_FILE_NAME_CONVERT='/oradata/orcl','/oradata/orcl' SCOPE=SPFILE;
ALTER SYSTEM SET LOG_FILE_NAME_CONVERT='/oradata/orcl','/oradata/orcl'  SCOPE=SPFILE;
ALTER SYSTEM SET STANDBY_FILE_MANAGEMENT=AUTO;

bash复制代码create pfile='/tmp/initorcl_stby.ora' from spfile;

--修改的部分：
*.db_unique_name=orcl_stby
*.fal_client='ORCL_STBY'
*.fal_server='ORCL'
*.log_archive_config='DG_CONFIG=(ORCL_STBY,ORCL)'
*.log_archive_dest_1='LOCATION=/archivelog VALID_FOR=(ALL_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=ORCL_STBY'
*.log_archive_dest_2='SERVICE=orcl ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=ORCL'

--复制参数文件至备库（备库执行）
scp oracle@orcl:/tmp/initorcl_stby.ora /tmp

--复制密码文件至备库（备库执行）,要在oracle用户下复制
su - oracle
scp oracle@orcl:/u01/app/oracle/product/11.2.0/db/dbs/orapworcl /u01/app/oracle/product/11.2.0/db/dbs

sql复制代码set line222
col member for a60
select t2.thread#,t1.group#,t1.member,t2.bytes/1024/1024 from gv$logfile t1,gv$log t2 where t1.group#=t2.group#;

   THREAD#     GROUP# MEMBER                                                       T2.BYTES/1024/1024
---------- ---------- ------------------------------------------------------------ ------------------
         1          3 /oradata/orcl/redo03.log                                                    120
         1          2 /oradata/orcl/redo02.log                                                    120
         1          1 /oradata/orcl/redo01.log                                                    120

--需要注意：
--1.stanby log日志大小与redo log日志保持一致
--2.stanby log数量： 
standby logfile=(1+logfile组数)*thread=(1+3)*1=4组,需要加4组standby logfile.
--3.thread要与redo log保持一致，如果是rac，需要增加多个thread对应的standby log

ALTER DATABASE ADD STANDBY LOGFILE thread 1 
group 4 ('/oradata/orcl/standby_redo04.log') SIZE 120M,
group 5 ('/oradata/orcl/standby_redo05.log') SIZE 120M,
group 6 ('/oradata/orcl/standby_redo06.log') SIZE 120M,
group 7 ('/oradata/orcl/standby_redo07.log') SIZE 120M;

bash复制代码su - oracle -c "mkdir -p /oradata/orcl"
su - oracle -c "mkdir -p /u01/app/oracle/fast_recovery_area/orcl"
su - oracle -c "mkdir -p /u01/app/oracle/admin/orcl/adump"

sqlplus / as sysdba
create spfile from pfile='/tmp/initorcl_stby.ora';
startup nomount

bash复制代码rman target sys/oracle@orcl AUXILIARY sys/oracle@orcl_stby

run {
allocate channel prmy1 type disk;
allocate channel prmy2 type disk;
allocate auxiliary channel aux1 type disk;
allocate auxiliary channel aux2 type disk;
DUPLICATE TARGET DATABASE FOR STANDBY FROM ACTIVE DATABASE DORECOVER NOFILENAMECHECK;
}

sql复制代码alter database open read only;

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT FROM SESSION;

select database_role,open_mode from v$database;

DATABASE_ROLE    OPEN_MODE
---------------- --------------------
PHYSICAL STANDBY READ ONLY WITH APPLY

SQL> SELECT protection_mode FROM v$database;

PROTECTION_MODE
--------------------
MAXIMUM PERFORMANCE

sql复制代码ALTER SYSTEM SET LOG_ARCHIVE_DEST_STATE_2=ENABLE;

sql复制代码set line222
col member for a60

--查看是否存在RFS和MRP进程
select process,group#,thread#,sequence# from gv$managed_standby;

--查看standby日志status是否存在active
select t1.group#,t1.thread#,t1.bytes/1024/1024,t1.status,t2.member from gv$standby_log t1,gv$logfile t2 where t1.group#=t2.group#;

--主库建表空间，建用户，建表，增删改测试
create tablespace TEST datafile '/oradata/orcl/test01.dbf' size 100M autoextend off;
create user test identified by test;
grant dba to test;
conn test/test
create table test(id number);
insert into test values (1);
insert into test values (2);
commit;

--备库查看是否同步

SQL> select tablespace_name from dba_tablespaces where tablespace_name='TEST';

TABLESPACE_NAME
------------------------------
TEST

SQL> select username,account_status,created from dba_users where username='TEST';

USERNAME                       ACCOUNT_STATUS                   CREATED
------------------------------ -------------------------------- ------------------
TEST                           OPEN                             17-APR-21

SQL> select * from test.test;

        ID
----------
         1
         2

ini复制代码//伪代码
public object GetProductListNew() {
    int cacheTime = 30;
    String cacheKey = "product_list";

    String cacheValue = CacheHelper.Get(cacheKey);
    if (cacheValue != null) {
        return cacheValue;
    }

    cacheValue = CacheHelper.Get(cacheKey);
    if (cacheValue != null) {
        return cacheValue;
    } else {
        //数据库查询不到，为空
        cacheValue = GetProductListFromDB();
        if (cacheValue == null) {
            //如果发现为空，设置个默认值，也缓存起来
            cacheValue = string.Empty;
        }
        CacheHelper.Add(cacheKey, cacheValue, cacheTime);
        return cacheValue;
    }
}

scss复制代码public String get(key) {
      String value = redis.get(key);
      if (value == null) { //代表缓存值过期
          //设置3min的超时，防止del操作失败的时候，下次缓存过期一直不能load db
      if (redis.setnx(key_mutex, 1, 3 * 60) == 1) {  //代表设置成功
               value = db.get(key);
                      redis.set(key, value, expire_secs);
                      redis.del(key_mutex);
              } else {  
              //这个时候代表同时候的其他线程已经load db并回设到缓存了，这时候重试获取缓存值即可
                      sleep(50);
                      get(key);  //重试
              }
          } else {
              return value;      
          }
 }

scss复制代码if (memcache.get(key) == null) {  
    // 3 min timeout to avoid mutex holder crash  
    if (memcache.add(key_mutex, 3 * 60 * 1000) == true) {  
        value = db.get(key);  
        memcache.set(key, value);  
        memcache.delete(key_mutex);  
    } else {  
        sleep(50);  
        retry();  
    }  
}

ini复制代码//伪代码
public object GetProductListNew() {
    int cacheTime = 30;
    String cacheKey = "product_list";
    String lockKey = cacheKey;

    String cacheValue = CacheHelper.get(cacheKey);
    if (cacheValue != null) {
        return cacheValue;
    } else {
        synchronized(lockKey) {
            cacheValue = CacheHelper.get(cacheKey);
            if (cacheValue != null) {
                return cacheValue;
            } else {
              //这里一般是sql查询数据
                cacheValue = GetProductListFromDB(); 
                CacheHelper.Add(cacheKey, cacheValue, cacheTime);
            }
        }
        return cacheValue;
    }
}

ini复制代码//伪代码
public object GetProductListNew() {
    int cacheTime = 30;
    String cacheKey = "product_list";
    //缓存标记
    String cacheSign = cacheKey + "_sign";

    String sign = CacheHelper.Get(cacheSign);
    //获取缓存值
    String cacheValue = CacheHelper.Get(cacheKey);
    if (sign != null) {
        return cacheValue; //未过期，直接返回
    } else {
        CacheHelper.Add(cacheSign, "1", cacheTime);
        ThreadPool.QueueUserWorkItem((arg) -> {
      //这里一般是 sql查询数据
            cacheValue = GetProductListFromDB(); 
          //日期设缓存时间的2倍，用于脏读
          CacheHelper.Add(cacheKey, cacheValue, cacheTime * 2);                 
        });
        return cacheValue;
    }
}