Recently it has been increasingly able to see the system configuration diagram in the business.

Because it is often do not know may be seen, I will try to learn something,

read the [technology to support the server/infrastructure].

Because much trouble, tried together to the extent that the bearded hair in the table of contents.

[Chapter 1] server/infrastructure construction Introduction

• The system must be designed so that failure is good even when going on
• For this purpose, router, load balancer, server, needs to be redundant all
• The important thing when you have redundancy,
  • Detection of failure (health check)
  • Smooth switching (takeover of the IP address)
• Scheduling algorithm, VRRP, and various mechanisms are used

Construction of [Chapter 2] up a notch server/infrastructure

• Using cache server as a reverse proxy can load distribution to the AP server
  • The content of the request, it is possible to switch the server (L7 switch role)
  • Return HTML, CSS, JS, static content such as images from the cache server
  • [HTTP protocol level: Squid], [Web application data: memcached]
• MySQL also redundant (replication), and effective use of slave
  • Request only by referring to data may be reference to the slave
  • Of course, keep to be in order in the slave also the internal load balancer (Linux)
• By using HTTP as the storage protocol, to avoid the risk of site is totally stopped
  • Necessary redundancy to prevent single point of failure
  • Failure-prone and leave synchronize files on multiple servers
  • These two problems in Chapter 3

[Chapter 3] further devised that aims to infrastructure that does not stop

• Although failure of the DNS server is not easily occur, is wide much more difficult impact of range Cause identified when that happened
  • To have a VIP to the load balancer, redundant in the Active/Active configuration. (IPVS, keepalive)
• Storage server synchronization is difficult -> solved using DRBD
  • DRBD: rather than a file-by-file basis, to replicate in real-time block device unit
  • To control the keepalivd in daemontools
  • Weakness that someone will be reflected in the backup as soon as you delete a file by mistake
• With Bonding driver, L1,/L2 also redundant (links, switches)
  • If redundant too loop she can (broadcast storm)
  • Resolved RSTP (blocking the automatic redundant connection)
• Flexibility to the network using a VLAN
  • Port VLAN: assign a VLAN identifier for each port on the switch
  • Tag VLAN: to insert the VLAN identification information in the Ethernet frame. Tend to be complicated logical configuration.
  • Use of a server farm, the use of the tag VLAN, Nakuseru the physical waste
  • The port VLAN as a basic, to perform the set of tag VLAN where needed ideal
  • Also VLAN configuration becomes complicated, physical configuration determine the simplicity

[Chapter 4] performance improvement, tuning

• In accordance with the redundancy of the past, there is a sense of first load distribution by drawing performance of a single host
  • Load is not to guess, to measure: see the load average
  • There are two types of CPU load and I/O load, find out which one is the bottleneck
  • ps, sar, vmstat, with the top ,,, various commands to make sure
  • By looking at the kernel code, deepen the understanding of the load calculation method
  • Tuning and discovers a bottle neck, only to remove it
• But can also be tuning in Web server (Apache), most of the cause exists in a different location
  • If by force increase, what to choose to MPM at the time of the parallel processing is important
  • Determining the MaxClients by the average memory consumption of physical memory and a process server installed
  • perfork: multi-process. Everyday use if good here.
  • worker: multi-threaded. It is a fast, lightweight, complex settings.
• Effective MySQL tuning table design and optimization of SQL is
  • It can be on the server side, the parameter tuning of memory relationship
  • Buffer: innodb_buffer_pool_size Toka Toka

[Chapter 5] labor-saving operation

• Used a variety of tools for labor-saving operation
• Nagios: service of the operation monitoring
  • Life-and-death states
  • Load state
  • Measurement of capacity utilization
• Ganglis: Monitoring of server resources
  • CPU usage, memory usage
  • Load balancer
  • Ne network traffic
• Puppet: efficiency of server management
  • Introduction of new server
  • Setting change of an existing server
  • Where the number is large, manual priority is a place setting leakage is likely to occur is
• deamontools: operation management of the daemon
  • Me re-start automatically when the process fell
  • Make the easy daemon
• PXE, initramfs: take advantage of the network boot
  • To read from a server on a network, there is no need to secondary storage device
  • Load balancer and DB, is often utilized in the file server
• Remote maintenance
  • Although it easier and remote login with SSH, can not be used with the OS is not running
  • To deal with a serial console, IPMI, etc.
• Handling of Web server log
  • To make it easier to handle the logs, aggregated in one place, there is a need to collect
  • It is used in the summary and analysis of the problems of access