1, Introduction to Tomcat
Originally developed by Sun's software architect James Duncan Davidson
After installing tomcat, the directories and files under the installation path are important files for using or configuring Tomcat
Tomcat important directory
bin: store the startup and shutdown Tomcat scripts
conf: store different configuration files of Tomcat
doc: store Tomcat documents
lib: store the library files required for Tomcat operation
logs: stores the log file during Tomcat execution
src: store the source code of tomcat
webapps: Tomcat's main web publishing directory
work: store the class file generated after jsp compilation
Nginx applications:
Nginx is an excellent HTTP server software
Support responses with up to 50000 concurrent connections
It has strong static resource processing ability
Stable operation
The consumption of system resources such as memory and CPU is very low
At present, many large websites use nginx server as the reverse proxy and load balancing of back-end website programs to improve the load concurrency of the whole site.
2, Nginx load balancing, dynamic and static separation principle
Illustration:
In the standalone mode, Tomcat runs alone and directly accepts user requests. It is not recommended.
The reverse agent, running on a single machine, provides an nginx as the reverse agent, which can provide static response from nginx and dynamic jsp
Agent to Tomcat
LNMT: Linux + Nginx + MySQL + Tomcat
LAMT: Linux + Apache(Httpd)+ MySQL + Tomcat
One Nginx is used in the front to do reverse proxy and load balancing scheduling for multiple Tomcat instances. The pure dynamic pages deployed on Tomcat are more convenient
fit
LNMT: Linux + Nginx + MySQL + Tomcat
Multilevel agent
LNNMT: Linux + Nginx + Nginx + MySQL + Tomcat
The problem with dynamic servers is that the concurrency capability is too weak, and multiple dynamic servers are often required to provide services together. How to allocate concurrent pressure requires scheduling. A certain scheduling strategy is adopted to distribute requests to different servers, which is Load Balance.
When single machine Tomcat evolves multi machine and multi-level deployment, a problem is highlighted, which is Session. The origin of this problem is that the HTTP protocol did not think of the future development at the beginning of its design.
3, Deploying the ngnix load balancer
Build the environment with three hosts:
nginx: 192.168.187.160
tomcat1:192.168.187.170
tomcat2:192.168.187.180
1. Install nginx
Turn off firewall and setenforce
systemctl stop firewalld.service setenforce 0
Install dependency package
[root@localhost opt]# yum -y install pcre-devel zlib-devel gcc gcc-c++ make
Upload the installation package and unzip it
cd /opt [root@localhost opt]# rz -E rz waiting to receive. [root@localhost opt]# ls nginx-1.12.0.tar(1).gz rh [root@localhost opt]# tar zxf nginx-1.12.0.tar\(1\).gz [root@localhost opt]# ls nginx-1.12.0 nginx-1.12.0.tar(1).gz rh
Enter the directory to compile and install
#Configuration parameter interpretation ./configure \ --prefix=/usr/local/nginx \ #Installation path --user=nginx \ #Specify user name --group=nginx \ #Specify user groups --with-http_stub_status_module #Enable this module to support status statistics --with-file-aio #Enable file modification support --with-http_gzip_static_module #Enable gzip static compression --with-http_flv_module #Enable the flv module to support flv video streaming --with-http_ssl_module #Enable ssl module and provide ssl encryption function --without #Enter the directory to compile and install cd /opt/nginx-1.12.0 ##compile ./configure --prefix=/usr/local/nginx --user=nginx --group=nginx --with-http_stub_status_module --with-file-aio --with-http_gzip_static_module --with-http_flv_module ##install make && make install
Create a new user for management
[root@localhost nginx-1.12.0]# useradd -M -s /sbin/nologin nginx
Establish soft link
[root@localhost nginx-1.12.0]# ln -s /usr/local/nginx/sbin/nginx /usr/local/sbin/
Configure system
[root@localhost nginx-1.12.0]# vim /lib/systemd/system/nginx.service configuration parameter [Unit] Description=nginx After=network.target [Service] Type=forking PIDFile=/usr/local/nginx/logs/nginx.pid ExecStart=/usr/local/nginx/sbin/nginx ExecReload=/usr/bin/kill -s HUP $MAINPID ExecStop=/usr/bin/kill -s QUIT $MAINPID PrivateTmp=true [Install] WantedBy=multi-user.target
Open service and view
##If you haven't started it before, just hit this step systemctl daemon-reload systemctl start nginx.service ss -napt | grep 80
Testing nginx on a web page
