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kafka topic 创建和删除

创建

bin/kafka-topics.sh --create --zookeeper localhost:2181 --topic api-gateway --partitions 1 --replication-factor 3

删除

bin/kafka-topics.sh --delete --zookeeper localhost:2181 --topic api-gateway

查看

/kafka-topics.sh --list --zookeeper localhost:2181

2017 年 9 月 25 日

etcdctl

检测 etcd 状态

etcdctl --endpoints http://127.0.0.1:4001 cluster-health

etcdctl member list
996585598035175a, started, etcd-0, http://etcd-0.etcd:2380, http://etcd-0.etcd:2379
9a7f19668a394adb, started, etcd-1, http://etcd-1.etcd:2380, http://etcd-1.etcd:2379
92dc397d93504108, started, etcd-2, http://etcd-2.etcd:2380, http://etcd-2.etcd:2379

# etcdctl --endpoints=[etcd-0.etcd:2379,etcd-1.etcd:2379,etcd-2.etcd:2379] endpoint health
etcd-0.etcd:2379 is healthy: successfully committed proposal: took = 4.658206ms
etcd-2.etcd:2379 is healthy: successfully committed proposal: took = 5.670776ms
etcd-1.etcd:2379 is healthy: successfully committed proposal: took = 5.608339ms

查看所有 a 开头的 key

etcdctl-3.2.26 get a --prefix --keys-only

查看所有 key

ETCDCTL_API=3 etcdctl get "" --prefix --keys-only

备份

etcdctl --endpoints=[etcd-0.etcd:2379,etcd-1.etcd:2379,etcd-2.etcd:2379]  snapshot save snapshot.db

2017 年 9 月 14 日

macOS 屏幕相关

1. mission control => 触发角 => 启用屏幕保护程序 or 将显示器置入睡眠状态
2. 安全性与隐私 => 进入睡眠或开始屏幕保护程序立即要求输入密码

接下来使用触发角就可以立即锁屏了

新版 mac 使用 ctrl + command + q

Question: how to quick switch between mirror and extended display in macOS
切换 mirror 和扩展模式: command + F1
If you need to temporarily see your Dock or your open windows on both displays, Command-F1 lets you accomplish this. It’s a shortcut to the System Preferences > Displays > Arrangement > Mirror Displays command.

2017 年 8 月 28 日
bee 自动运行 go 项目
当源代码有过修改之后，自动 build 重启
```
~/go/bin/bee run logan
```
2017 年 8 月 21 日

kafka修改 topic retention

查看所有的 topic

bin/kafka-topics.sh --list --zookeeper localhost:2181

修改为 60s


# bin/kafka-configs.sh --zookeeper localhost:2181 --alter --entity-name provider-service --entity-type topics --add-config retention.ms=60000

查看

# bin/kafka-configs.sh --zookeeper localhost:2181 --describe --entity-name provider-service --entity-type topics
Configs for topics:provider-service are retention.ms=60000

2017 年 8 月 11 日

bash countdown

输入 countdown + 秒数，就开始倒计时了

gnu date

function countdown(){  
    local now=$(date +%s)
    local end=$((now + $1))
    while (( now < end )); do   
        printf "%s\r" "$(date -u -d @$((end - now)) +%T)"  
        sleep 0.25  
        now=$(date +%s)
    done  
    echo
}

osx date

function countdown(){  
    echo $2
    local now=$(date +%s)
    local end=$((now + $1))
    while (( now < end )); do   
        printf "%s\r" "$(date -u -j -f %s $((end - now)) +%T)"  
        sleep 0.25  
        now=$(date +%s)
    done
}

参考:https://superuser.com/questions/850368/osx-bash-command-line-countdown-timer?answertab=votes#tab-top