Redis的哨兵模式给着实给我看乐了，哨兵(sentinel)们就像将军，主服务器(master)就像皇帝，从服务器(slave)就像是太子，哨兵们平时啥也不干就盯着皇帝是不是死了(下线)，一旦master挂了就开始忙活，发现皇帝死了先不好声张，记上"主观认为"皇帝已死，同时赶紧给其他哨兵发消息：皇帝是不是真死了？(is_master_down_by_addr)如果几个朋友都认为皇帝死了，那就"客观认为"皇帝已死，一旦确认皇帝死了(>quorum)，马上开始搞选举(选举领头Sentinel)，告诉其他哨兵:我先发现皇帝挂了，你们应该选举我为领头人来主持权力交接(故障转移)，尽管每个哨兵都这么认为但是大家还是遵守规矩先到先得(比网速，比算力，比运气)，如此一来便选举出反应最灵敏(网速，性能)的哨兵成为领头人。上台第一件事就是改年号(epoch+1)表示改朝换代了，领头人找来皇帝的所有儿子(该主服务器下所有从服务器slave)开始挑，有病的儿子不要(断线服务器)，傻儿子不要-反应慢(最近5秒通信)，非亲生的不要(过早与主服务器断联导致不一致性强)，最亲近的儿子优先(复制偏移量较大)，如果最后还是有多个候选，就捡年龄最大(id最小)那个，接着领头哨兵把选出来的太子立为新王(new master)，其他兄弟们只能给新王当小弟(slave)，万一哪天他爹复活了(重新上线)，不好意思已经改朝换代了，只能去给新的master当slave。Talk is cheap， show me the code .看实现，把如此复杂的逻辑用最简洁的方法实现，我服了，Redis真牛，作者真牛！
High Energy Impact
IT 406, 542, and 800 Pendulum Impact
Tinius Olsen’s pendulum impact testers are versatile and reliable machines designed to fully comply with the specifications outlined in ASTM E23, EN10045-2 and ISO 148. Today, the Model IT406 and the Model IT542 are widely recognized as the standards of the industry for impact testing.
Tinius Olsen offers a number of options to make the operation of the impact tester easier—from a simple electric brake to slow the swinging pendulum to a stop, to an automatic motorized return, eliminating the need for any operator involvement other than releasing the pendulum.
Machines with a digital display can be linked to a stand alone PC and connected to Tinius Olsen’s Horizon software. For high traffic areas, Tinius Olsen can supply a complete enclosure for the machine so that the swinging pendulum and broken specimens do not pose any safety concerns. The enclosure is completely
interlocked so that the machine cannot operate unless all the guards are in place.
Downloads & links
Email us
Contact (Phone/Addr)
High Energy Impact Specifications https://t.cn/RC4OzyP
IT 406, 542, and 800 Pendulum Impact
Tinius Olsen’s pendulum impact testers are versatile and reliable machines designed to fully comply with the specifications outlined in ASTM E23, EN10045-2 and ISO 148. Today, the Model IT406 and the Model IT542 are widely recognized as the standards of the industry for impact testing.
Tinius Olsen offers a number of options to make the operation of the impact tester easier—from a simple electric brake to slow the swinging pendulum to a stop, to an automatic motorized return, eliminating the need for any operator involvement other than releasing the pendulum.
Machines with a digital display can be linked to a stand alone PC and connected to Tinius Olsen’s Horizon software. For high traffic areas, Tinius Olsen can supply a complete enclosure for the machine so that the swinging pendulum and broken specimens do not pose any safety concerns. The enclosure is completely
interlocked so that the machine cannot operate unless all the guards are in place.
Downloads & links
Email us
Contact (Phone/Addr)
High Energy Impact Specifications https://t.cn/RC4OzyP
显示网络设备信息命令ifconfig：
eth0 表示第一块网卡， 其中 HWaddr 表示网卡的物理地址，可以看到目前这个网卡的物理地址(MAC地址）是 00:50:56:BF:26:20
inet addr 用来表示网卡的IP地址，此网卡的 IP地址是 192.168.120.204，广播地址， Bcast:192.168.120.255，掩码地址Mask:255.255.255.0 。#计算机网络知识大讲堂#
eth0 表示第一块网卡， 其中 HWaddr 表示网卡的物理地址，可以看到目前这个网卡的物理地址(MAC地址）是 00:50:56:BF:26:20
inet addr 用来表示网卡的IP地址，此网卡的 IP地址是 192.168.120.204，广播地址， Bcast:192.168.120.255，掩码地址Mask:255.255.255.0 。#计算机网络知识大讲堂#
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