1.1 What is the operation and maintenance?
1. What is the operation and maintenance
1. operation and maintenance means that large organizations have established a good network of hardware and software maintenance, on-line is to ensure that normal business and operations.
2. In the course of his operation, as for him to maintain his collection of networks, systems, databases, development, security, monitoring in-one technology.
3 also includes a variety of operation and maintenance, have DBA operation and maintenance, site operation and maintenance, operation and maintenance of virtualization, monitoring, operation and maintenance, game operation and maintenance and so on.
Operation and maintenance Category:
1) the development of operation and maintenance: is to the application operation and maintenance development operation and maintenance tools and operation and maintenance platform
2) application operation and maintenance: is for the line of business, Maintenance and do troubleshooting, with the development of operation and maintenance developed tools to business lines, maintenance, do troubleshooting
3) system operation and maintenance: is the transport infrastructure to the application on a business dimension to provide, such as: system, network monitoring, hardware, etc.
1.2 You are given three hundred servers, how do you manage them?
1, now give you three hundred servers, how do you manage them
1. Set stepping stones, using a unified account login, easy to considerations of security and login.
2. Use salt, ansiable, puppet unified unified management and configuration of the system.
3. Establish a simple system server configuration, cmdb information management applications. Easy access to a variety of information recorded on each server.
1.3 LVS, Nginx, HAproxy What is the difference? Work how you choose?
1, LVS, Nginx, HAproxy What is the difference?
1. LVS: forwarding is based on the four
2. HAproxy: Forwarding is based on four and seven, it is the professional proxy server
3. Nginx: a WEB server, cache server, but also a reverse proxy server, you can do seven forwards
the difference:
1) LVS forward because it is based on four layers so you can only do port forwarding
2) and URL-based, forward LVS based on this catalog can not do
2. Work Choices
1. HAproxy and Nginx can make due forward seven, so the URL forwarding and directories can be done
2. In a large amount of concurrent time we will choose LVS, like small and medium sized company if concurrency is not so big
3. Select HAproxy or Nginx enough already, due HAproxy by a professional proxy server, simple configuration, small and medium enterprises recommended HAproxy
1.4 What is CDN?
1. What is CDN?
1. That content delivery network
2. Its purpose is to add a new layer of network architecture in the existing Internet, the content posted to the site
3. The network edge closest to the user, the user can go to obtain the desired content, improve user access to the site speed
1.5 What is the website gray publish?
1. What is the gray release?
1. The release refers to a release gray between black and white, can be a smooth transition manner
2. AB test is a kind of gray distribution so that a user continues with A, some users start with B
3. If the user does not have any objections to B, then gradually expand the scope, all users are migrated to the B to the top
4. grayscale release can ensure the stability of the overall system, can be found in the initial gray when the adjustment problems, in order to ensure that the impact of
1.6 Description of DNS for name resolution process?
1, DNS name resolution process?
1. To access the user www.baidu.com, the machine will go first to the host file
2. find a local DNS server setting, if no, then went to the network to find the root servers, root servers feedback results
3. say can only provide a domain name server .cn, went to a domain name server
A domain name server to provide secondary domain name server can only say .com.cn, went to the secondary domain name server
Second-level domain server can only provide three domain name server .baidu.com.cn, went to three domain name server
Third-level domain servers just have this site www.baidu.com, then the request to the server, and after a save, and then distributed to the client
1.7 Keepalived talk about the principle of?
1, talk about the principle of Keepalived?
1. In a virtual router, only as a MASTER of VRRP router sends VRRP information will always BACKUP will not seize MASTER, unless it is the higher priority.
2. When MASTER is unavailable (BACKUP not receive notification information) multiple BACKUP highest priority of this will be preempted as MASTER.
3. This preemption is very fast (<1s), in order to ensure continuity of service
4. Because of security reasons, the encryption protocol using the VRRP packet is encrypted, the BACKUP will not send advertisement information, only receive announcement information