分类目录归档:系统管理

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How to Install and Configure ‘Cache Only DNS Server’ with ‘Unbound’ in RHEL/CentOS 7

Version:1.0 StartHTML:000000222 EndHTML:000042418 StartFragment:000012983 EndFragment:000042312 StartSelection:000012983 EndSelection:000042308 SourceURL:https://www.tecmint.com/setup-dns-cache-server-in-centos-7/ How to Install and Configure ‘Cache Only DNS Server’ with ‘Unbound’ in RHEL/CentOS 7

Caching name servers using ‘Unbound‘ ( is a validating, recursive, and caching DNS server software ), back in RHEL/CentOS 6.x (where x is version number), we used bind software to configure DNS servers.

Here in this article, we are going to use ‘unbound‘ caching software to install and configure a DNS Server in RHEL/CentOS 7 systems.

Setup Cahing DNS Server in RHEL/CentOS 7

DNS cache servers are used to resolve any DNS query they receive. If the server caches the query and in future the same queries requested by any clients the request will be delivered from DNS ‘unbound‘ cache, this can be done in milliseconds than the first time it resolved.

Caching will only act as a agent to resolve the query of client from any one of the forwarders. Using caching server, will reduce the loading time of webpages by keeping the cache database in unbound server.

My Server and Client Setup

For demonstration purpose, I will be using two systems. The first system will act as a Master (Primary) DNS server and the second system will act as a local DNS client.

Master DNS Server
Operating System   :    CentOS Linux release 7.0.1406 (Core)
IP Address	   :	192.168.0.50
Host-name	   :	ns.tecmintlocal.com
Client Machine
Operating System   :	CentOS 6
IP Address	   :	192.168.0.100
Host-name	   :	client.tecmintlocal.com

Step 1: Check System Hostname and IP

1. Before setting up a caching DNS server, make sure that you’ve added correct hostname and configured correct static IP address for your system, if not set the system static IP address.

2. After, setting correct hostname and static IP address, you can verify them with the help of following commands.

# hostnamectl
# ip addr show | grep inet

Check IP Address

Step 2: Installing and Configuring Unbound

3. Before installing ‘Unbound’ package, we must update the our system to latest version, after that we can install the unbound package.

# yum update -y
# yum install unbound -y

4. After package has been installed, make a copy of the unbound configuration file before making any changes to original file.

# cp /etc/unbound/unbound.conf /etc/unbound/unbound.conf.original

5. Next, use any of your favorite text editor to open and edit ‘unbound.conf‘ configuration file.

# vim /etc/unbound/unbound.conf
Copy Unbound DNS Configuration

Once the file is opened for editing, make the following changes:

Interfaces

Search for Interface and enable the interface which we going to use or if our server have multiple interfaces we have to enable the interface 0.0.0.0.

Here Our server IP was 192.168.0.50, So, i’am going to use unbound in this interface.

Interface 192.168.0.50
Enable IPv4 and Protocol Supports

Search for the following string and make it ‘Yes‘.

do-ip4: yes
do-udp: yes
do-tcp: yes
Enable the logging

To enable the log, add the variable as below, it will log every unbound activities.

logfile: /var/log/unbound
Hide Identity and Version

Enable following parameter to hide id.server and hostname.bind queries.

hide-identity: yes

Enable following parameter to hide version.server and version.bind queries.

hide-version: yes
Access Control

Then search for access-control to allow. This is to allow which clients are allowed to query this unbound server.

Here I have used 0.0.0.0, that means anyone send query to this server. If we need to refuse query for some range of network we can define which network need to be refuse from unbound queries.

access-control: 0.0.0.0/0 allow

Note: Instead of allow, we can replace it with allow_snoop this will enable some additional parameters like dig and it support both recursive and non recursive.

Domain Insecure

Then search for domain-insecure. If our domain is works with DNS sec keys, we need to define our server available for domain-insecure. Here our domain will be treated as insecure.

domain-insecure: "tecmintlocal.com
Forward Zones

Then change the forwarders for our requested query not fulfilled by this server it will forward to root domain (. ) and resolve the query.

forward-zone:
        name: "."
        forward-addr: 8.8.8.8
        forward-addr: 8.8.4.4

Finally, save and quit the configuration file using wq!.

6. After making the above configuration, now verify the unbound.conf file for any errors using the following command.

# unbound-checkconf /etc/unbound/unbound.conf

Check Unbound DNS Configuration

7. After file verification over without any errors, you can safely restart the ‘unbound’ service and enable it at system startup.

# systemctl start unbound.service
# sudo systemctl enable unbound.service

Start Unbound DNS Service

Step 3: Test DNS Cache Locally

8. Now it’s time to check our DNS cache, by doing a ‘drill’ (query) one ‘india.com‘ domain. At first the ‘drill‘ command results for ‘india.com‘ domain will take some milliseconds, and then do a second drill and have a note on Query time it takes for both drills.

drill india.com @192.168.0.50

Check DNS Cache Locally

Did you see in the above output, the first query taken almost 262 msec to resolve and the second query takes 0 msec to resolve domain (india.com).

That means, the first query gets cached in our DNS Cache, so when we run ‘drill’ second time the query served from our local DNS cache, this way we can improve loading speed of websites.

Step 4: Flush Iptables and Add Firewalld Rules

9. We can’t use both iptables and firewalld at same time on same machine, if we do both will conflict with each other, thus removing ipables rules will be a good idea. To remove or flush the iptables, use the following command.

# iptables -F

10. After removing iptables rules permanently, now add the DNS service to firewalld list permanently.

# firewall-cmd --add-service=dns
# firewall-cmd --add-service=dns --permanent

11. After adding DNS service rules, list the rules and confirm.

# firewall-cmd --list-all

Add DNS to Firewalld

Step 5: Managing and Troubleshooting Unbound

12. To get the current server status, use the following command.

# unbound-control status

Check Unbound DNS Status

Dumping DNS Cache

13. If in-case you would like to have a dump of a DNS cache information in a text file, you can redirect it to some file using below command for future use.

 # unbound-control dump_cache > /tmp/DNS_cache.txt

Backup DNS Cache

14. To restore or import the cache from the dumped file, you can use following command.

# unbound-control dump_cache < /tmp/DNS_cache.txt

Restore DNS Cache

Flushing DNS Records

15. To check whether the specific address was resolved by our forwarders in unbound cache Server, use the below command.

# unbound-control lookup google.com

Check DNS Lookup

16. Some times if our DNS cache server will not reply our query, in mean time we can use to flush the cache to remove information such as A, AAA, NS, SO, CNAME, MX, PTR etc.. records from DNS cache. We can remove all information using flush_zone this will remove all informations.

# unbound-control flush www.digitalocean.com
# unbound-control flush_zone tecmintlocal.com

17. To check which forwards are currently used to resolve.

# unbound-control list_forwards

Check Current DNS Forwards

Step 6: Client Side DNS Configuration

18. Here I’ve used a CentOS 6 server as my client machine, IP for this machine is 192.168.0.100 and I’m going to use my unbound DNS server IP (i.e Primary DNS) in it’s interface configuration.

Log-into the Client machine and set the Primary DNS server IP to our unbound server’s IP.

Run the setup command and choose network configuration from TUI network manager.

Then choose DNS configuration, insert the unbound DNS server’s IP as Primary DNS, but here i have used both in Primary and Secondary because I don’t have any other DNS server.

Primary DNS	: 192.168.0.50
Secondary DNS	: 192.168.0.50

Select Network Configuration

Select DNS Configuration

Enter DNS IP Address

Click OK –> Save&Quit –> Quit.

19. After adding Primary and Secondary DNS IP addresses, now it’s time to restart the network using following command.

# /etc/init.d/network restart

Restart Network

20. Now time to access any one of the website from client machine and check for the cache in unbound DNS server.

# elinks aol.com
# dig aol.com

Check Website

Query Website

Conclusion

Earlier we were used to setup DNS cache server using bind package in RHEL and CentOS systems. Now, we have seen how to setup a DNS cache server using unbound package. Hope this will resolve your query request quicker than the bind pacakge.

Linux 磁盘IO性能测试工具:FIO

1、FIO安装

CentOS下:

$ yum install fio

2、FIO简介

FIO是测试IOPS的非常好的工具,用来对硬件进行压力测试和验证。
项目主页:https://github.com/axboe/fio
FIO输出结果详细解释可参见:https://tobert.github.io/post/2014-04-17-fio-output-explained.html
注:fio用于测试磁盘性能,不是文件系统,测试之前需要先把要测试的磁盘卸载掉,测试完后需格式化一遍再挂载上去。相关命令如下:

# 卸载磁盘
umount /mnt/datadir1
# 格式化磁盘
mkfs.ext4 /dev/sdd
# 挂载磁盘
mount -t ext4 /dev/sdd /mnt/datadir1

# 自动挂载,在里面添加该盘
vim /etc/fstab

3、FIO参数

例如:

$ fio -filename=/dev/sda -direct=1 -iodepth 1 -thread -rw=read -ioengine=psync -bs=16k -size=200G -numjobs=30 -runtime=1000 -group_reporting -name=mytest1

说明:
filename=/dev/sdd 测试文件名称,通常选择需要测试的盘的data目录。
direct=1 测试过程绕过机器自带的buffer。使测试结果更真实。
rw=randwrite 测试模式
=read 顺序读
=write 顺序写
=randwrite 随机写
=randread 随机读
=rw,readwrite 顺序混合读写
=randrw 随机混合读写

bs=4k 单次io的块文件大小为4k
bsrange=512-2048 同上,提定数据块的大小范围
size=5G 本次的测试文件大小为5g,以每次4k的io进行测试。
numjobs=30 本次的测试线程为30个
runtime=1000 测试时间为1000秒,如果不写则一直将5g文件分4k每次写完为止
iodepth 队列深度,只有使用libaio时才有意义。这是一个可以影响IOPS的参数。
ioengine=psync io引擎使用psync方式
=libaio Linux专有的异步IO

rwmixwrite=30 在混合读写的模式下,写占30%
group_reporting 关于显示结果的,汇总每个进程的信息。
lockmem=1G 只使用1g内存进行测试。
zero_buffers 用0初始化系统buffer。
nrfiles=8 每个进程生成文件的数量。

点击查看更多详细参数说明

4、FIO测试示例

fio工具使用特别注意:

  1. 请不要在系统盘上进行 fio 测试,避免损坏系统重要文件
  2. fio测试建议在空闲的、未保存重要数据的硬盘上进行,并在测试完后重新制作文件系统。请不要在业务数据硬盘上测试,避免底层文件系统元数据损坏导致数据损坏
  3. 测试硬盘性能时,推荐直接测试裸盘(如 vdb);测试文件系统性能时,推荐指定具体文件测试(如 /data/file)

4.1 顺序读测试

$ fio -ioengine=libaio -bs=4k -direct=1 -thread -rw=read -filename=/dev/sdd -name=”BS 4KB read test” -iodepth=16 -runtime=601

4.2 顺序写测试

$ fio -ioengine=libaio -bs=4k -direct=1 -thread -rw=write -filename=/dev/sdd -name=”BS 4KB write test” -iodepth=16 -runtime=601

4.3 随机读测试

$ fio -ioengine=libaio -bs=4k -direct=1 -thread -rw=randread -filename=/dev/sdd -name=”BS 4KB randread test” -iodepth=16 -runtime=601

4.4 随机写测试

$ fio -ioengine=libaio -bs=4k -direct=1 -thread -rw=randwrite -filename=/dev/sdd -name=”BS 4KB randwrite test” -iodepth=16 -runtime=601

4.5 随机读写混合测试

$ fio -ioengine=libaio -bs=4k -direct=1 -thread -rw=randrw -rwmixread=70 -filename=/dev/sdd -name=”BS 4KB randrw 70 test” -iodepth=16 -runtime=601

5、FIO输出结果

例如:

BS 4KB randread test: (g=0): rw=randread, bs=4K-4K/4K-4K/4K-4K, ioengine=libaio, iodepth=1
fio-2.1.10
Starting 1 thread

BS 4KB randread test: (groupid=0, jobs=1): err= 0: pid=26408: Mon Feb 27 16:43:07 2017
read : io=19908KB, bw=339689B/s, iops=82, runt= 60013msec
# fio做了19908KB的IO,bandwidth速率为339689B/s,总IOPS为82,运行时间为60013毫秒

slat (usec): min=18, max=97, avg=23.60, stdev= 2.79
# slat (submission latency):代表 盘需要多久将IO提交到kernel做处理
# usec 微秒

clat (msec): min=1, max=23, avg=12.03, stdev= 3.79
# clat (completion latency):命令提交到kernel到IO做完之间的时间,不包括submission latency

 lat (msec): min=1, max=23, avg=12.05, stdev= 3.79
# 从IO结构体创建时刻开始,直到紧接着clat完成的时间

clat percentiles (usec):
 |  1.00th=[ 4080],  5.00th=[ 5984], 10.00th=[ 7136], 20.00th=[ 8640],
 | 30.00th=[ 9920], 40.00th=[10944], 50.00th=[11840], 60.00th=[12992],
 | 70.00th=[14016], 80.00th=[15296], 90.00th=[17024], 95.00th=[18560],
 | 99.00th=[20864], 99.50th=[21632], 99.90th=[22400], 99.95th=[22912],
 | 99.99th=[23168]
# Completion latency百分数

bw (KB  /s): min=  276, max=  373, per=100.00%, avg=331.54, stdev=18.83
# 带宽(bandwidth)

lat (msec) : 2=0.02%, 4=0.82%, 10=30.32%, 20=66.75%, 50=2.09%
# 30.32%的request延迟在4~10毫秒,66.75%的request延迟在10~20毫秒,以此类推

cpu : usr=0.10%, sys=0.25%, ctx=5057, majf=0, minf=8
# 用户/系统CPU占用率,进程上下文切换(context switch)次数,主要和次要(major and minor)页面错误数量(page faults)。由于测试是配置成使用直接IO,page faults数量应该极少。

IO depths : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
# iodepth设置,用来控制同一时刻发送给OS多少个IO。这完全是纯应用层面的行为,和盘的IO queue不是一回事

 submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
 complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
 #submit和complete代表同一时间段内fio发送上去和已完成的IO数量

 issued    : total=r=4977/w=0/d=0, short=r=0/w=0/d=0
 # 发送的IO数量

 latency   : target=0, window=0, percentile=100.00%, depth=1
 # Fio可以配置一个延迟目标值,这个值可以调节吞吐量直到达到预设的延迟目标

Run status group 0 (all jobs):

Fio支持把不同的测试聚合

READ: io=19908KB, aggrb=331KB/s, minb=331KB/s, maxb=331KB/s, mint=60013msec, maxt=60013msec
# 汇总输出吞吐量和时间。
# io=表示总共完成的IO数量。在基于时间的测试中这是一个变量,在基于容量的测试中,这个值能匹配size参数。
# aggrb是所有进程/设备的汇总带宽。
# minb/maxb表示测量到的最小/最大带宽。
# mint/maxt表示测试的最短和最长耗时。和io=参数类似,时间值对于基于时间的测试应该能匹配runtime参数,对于基于容量的测试是一个变量。

Disk stats (read/write):
sdd: ios=4969/0, merge=0/0, ticks=59703/0, in_queue=59702, util=99.51%

How to Install Windows on RAID 5 with Drives Larger than 2TB

Setting Up the PERC with the DISKPART Tool for Windows Install

This type of RAID array requires a partition using a GUID (Globally Unique Identifier) Partition Table (GPT) to work properly for Windows in UEFI BIOS mode. Windows Setup, however, does not support making a GPT partition in the standard setup dialogue. Diskpart from the Command Prompt must be used to create a GPT partition to allow setup to see the RAID partition and continue setup.


Figure 1

  1. Start the install, and load the PERC H310 drivers via the OS “Load Diver” function. After the driver is loaded the RAID volume will appear in the install to device list (Figure 1).
  2. Press Shift+F10 to bring up a Command Prompt window.
  3. Type DISKPART and press Enter to enter the DISKPART tool. Enter the commands in the following steps as shown in bold and press enter.
  4. DETAIL DISK – This shows a list of volumes seen by the system. Make note of the Volume number for the RAID array.
  5. SELECT DISK=X – X will be the Volume number of the RAID shown in the detail disk report.
  6. CLEAN – Clears the partition information.
  7. CONVERT GPT – Sets the partition to GPT.
  8. EXIT – Exits DISKPART.
  9. Exit the Command Prompt window.
  10. The full RAID volume should show in the device list.
  11. Complete the remainder of the installation process normally. The RAID volume should show as “Windows Boot Manager” in UEFI.

If this was completed correctly, the system should boot normally in UEFI BIOS mode, and allow Windows to install.

Configure IIS to listen on specific IPs

By default IIS will listen for connections on port 80 for any IP bound to the server. This happens even if there are no host headers or bindings set for a specific IP. This can be a problem when trying to run multiple web servers on port 80.

To set IIS to listen on specific IPs follow the instructions below.

Windows Server 2003/IIS 6:

1. This requires the Server 2003 support tools. If this is not already installed it can be downloaded here.

2. Once installed open a command prompt and navigate to the support tools installation folder (default is C:\Program Files\Support Tools).
cd C:\Program Files\Support Tools

3. Stop http.
net stop http /y

4. Use this command to display the current list of IPs:
httpcfg query iplisten

5. By default it will listen on all IPs (0.0.0.0) so we can remove this.
httpcfg delete iplisten -i 0.0.0.0

6. Specify the IP(s) that IIS should listen on. Make sure to update 127.0.0.1 to the desired IP and run the command for each IP IIS should listen on.
httpcfg set iplisten -i 127.0.0.1

7. Start http and test out your sites.
net start http

Windows Server 2008/IIS 7:

1. Open a command prompt and type “netsh”.
netsh

2. Type “http”.
http

3. Enter the following command to display the current list of IPs to listen on. Note if no IPs are displayed like in the below image, IIS will listen on all IPs (default).
show iplisten

4. Use the command below to set IIS to listen on a specific IP. Make sure to replace 127.0.0.1 with the correct IP and run the command again for any additional addresses.
add iplisten ipaddress=127.0.0.1

5. In case you need to delete an IP from this list, use the following command.
delete iplisten ipaddress=127.0.0.1

6. Restart IIS to apply these changes.
iisreset

IIS listening 127.0.0.1 instead 0.0.0.0

I use command:

netsh http show iplisten

and saw 127.0.0.1 in listening list. (But I didn’t add it manually). So I delete it and add 0.0.0.0 instead.

netsh http delete iplisten ipaddress=127.0.0.1

netsh http add iplisten ipaddress=0.0.0.0

Then I restarted iis server.

SSL certificates on Sites with Host Headers

Source:https://blogs.iis.net/thomad/ssl-certificates-on-sites-with-host-headers

Today I got the following question:

“I have two sites (siteV1.mysite.com and sitev2.mysite.com). They listen on the same IP address and port. We generated a certificate for siteV1.mysite.com and SSL is working properly. The problem is that some of our customers use siteV2.mysite.com and they are getting certificate errors. What’s the problem?”

Here is the issue:

There are three pieces of data to uniquely identify an IIS site:

  • The IP address
  • The Port
  • The Host name which HTTP 1.1 clients send as an HTTP request header. 

This IP:Port:Hostname triplet is called a binding. The binding “192.168.1.192:80:myserver” for example represents a site that listens on IP address 192.168.1.192, port 80, host-header myserver

The very first things IIS (HTTP.SYS to be more precise) does when a request comes in is to read the site’s configuration. Connection limits and timeouts are examples of site configuration. The site binding is used to find the right site configuration. The SSL certificate seems to be another great example of site configuration – the SSL certificate is needed to decrypt the encrypted SSL data coming from the client.

And the IIS User Interface certainly makes it appear as if the SSL certificate would be site configuration, too – doesn’t it? In reality however you can’t bind a SSL certificate to a site. The IIS UI is fooling you. But why? 

It’s a chicken and egg problem: The host name is encrypted in the SSL blob that the client sends. Because the host name is part of the binding IIS needs the host name to lookup the right certificate. Without the host name IIS can’t lookup the right site because the binding is incomplete. Without the certificate IIS can’t decrypt the SSL blob that contains the host name. Game over – we are turning in circles. 

What IIS does under the covers is to ignore the host name. IIS binds the certificate to IP:Port and warns you when you try to bind a certificate to the same IP:Port combo with different host names. 

But there is a way if you need two different sites on the same IP:Port. You can accomplish this by getting a certificate that contains both common names, i.e. sitev1.mysite.com and sitev2.mysitem.com. Cert Authorities usually allow more than one so called “common names” in a certificate. By binding the certificate to one of the two sites you won’t not get certificate errors anymore. The client is happy if one of the names in the certificate matches. 

But there is another caveat: you can’t use the IIS7 User Interface to add a host header to an SSL site binding. You have to use command-line tools, do it programmatically or edit applicationhost.config directly. Here is an example and a link how you can it via command-line:

appcmd set site /site.name:”MySite V2″ /+bindings.[protocol=’https’,bindingInformation=’*:443:sitev2.mysite.com’]

And last but not least: with IIS7 you can use the following command to figure out what certificate is bound to a particular IP:Port combination:  
netsh http show sslcert

This command will show the IP:Port binding but also some other SSL settings.

Windows Process Activation Service error 5 – Access Denied

解决办法:C:\INETPUB\HISTORY. Under here you will see several folders with a prefix of CFGHISTORY. The folder with the highest revision number will be your latest backup. Copy this file and overwrite the existing file at C:\WINDOWS\SYSTEM32\INETSRV\CONFIG.

I ran into a strange error recently on an Exchange 2013 server. The WWW Publishing Service was stopped. When I tried to start the service it failed on a dependency. A quick check revealed the Windows Process Activation Service (WAS) was stopped. When I tried to start WAS, I received the following error.

Windows could not start the Windows Process Activation Service service on Local Computer Error 13 The data is invalid

Windows could not start the Windows Process Activation Service service on Local Computer. Error 13: The data is invalid.

The Event Viewer was littered with equally cryptic Event IDs, such as WAS 5005 and WAS 5036. 继续阅读

SSL证书格式详解与转换

一般来说,主流的 Web 服务软件,通常都基于 OpenSSL 和 Java 两种基础密码库。

  • Tomcat、Weblogic、JBoss 等 Web 服务软件,一般使用 Java 提供的密码库。通过 Java Development Kit (JDK)工具包中的 Keytool 工具,生成 Java Keystore(JKS)格式的证书文件。
  • Apache、Nginx 等 Web 服务软件,一般使用 OpenSSL 工具提供的密码库,生成 PEM、KEY、CRT 等格式的证书文件。
  • IBM 的 Web 服务产品,如 Websphere、IBM Http Server(IHS)等,一般使用 IBM 产品自带的 iKeyman 工具,生成 KDB 格式的证书文件。
  • 微软 Windows Server 中的 Internet Information Services(IIS)服务,使用 Windows 自带的证书库生成 PFX 格式的证书文件。

继续阅读

Optimizing Nginx for serving files bigger than 1GB

Yesterday I faced a strange issue, I realize that nginx was not serving files larger than 1GB. After investigation I found that it was due to the proxy_max_temp_file_size variable, that is configured by default to serve up to 1024 MB max.

This variable indicates the max size of a temporary file when the data served is bigger than the proxy buffer. If it is indeed bigger than the buffer, it will be served synchronously from the upstream server, avoiding the disk buffering.
If you configure proxy_max_temp_file_size to 0, then your temporary files will be disabled.

In this fix it was enough to locate this variable inside the location block, although you can use it inside server and httpd blocks. With this configuration you will optimize nginx for serving more than 1GB of data.

location / {
...
proxy_max_temp_file_size 1924m;
...
}

Restart nginx to take the changes:

service nginx restart

Smart and Efficient Byte-Range Caching with NGINX & NGINX Plus

When correctly deployed, caching is one of the quickest ways to accelerate web content. Not only does caching place content closer to the end user (thus reducing latency), it also reduces the number of requests to the upstream origin server, resulting in greater capacity and lower bandwidth costs.

The availability of globally distributed cloud platforms like AWS and DNS‑based global load balancing systems such as Route 53 make it possible to create your own global content delivery network (CDN).

In this article, we’ll look at how NGINX and NGINX Plus can cache and deliver traffic that is accessed using byte‑range requests. A common use case is HTML5 MP4 video, where requests use byte ranges to implement trick‑play (skip and seek) video playback. Our goal is to implement a caching solution for video delivery that supports byte ranges, and minimizes user latency and upstream network traffic.

Editor – The cache‑slice method discussed in Filling the Cache Slice‑by‑Slice was introduced in NGINX Plus R8. For an overview of all the new features in that release, see Announcing NGINX Plus R8 on our blog. 继续阅读

使用Nginx反向代理做cache缓存-实现CDN功能

目标

使用Nginx反向代理做cache缓存-实现CDN功能

环境

192.168.56.11是CDN节点
192.168.56.12是资源源站

源站nginx配置

源站nginx配置:
yum install -y nginx
hostnamectl set-hostname linux-node2
echo "This is linux-node2" >/usr/share/nginx/html/index.html
端口修改为8080
nginx -t
systemctl status nginx

要求:能正常使用curl请求访问资源。
curl -H "Host:www.exmail.com" http://192.168.56.12:8080

CDN节点-配置

继续阅读