Shulou(Shulou.com)06/03 Report--

What the editor shares today is the nginx+tomcat+redis+mysql implementation of session conversation technology, which you may not know very well. But don't worry, today the editor will explain it with the simplest description. Let's move on. First, redis introduction

Redis is a key-value storage system. Similar to memcached, it supports storing relatively more value types, including string (string), list (list), set (collection), zset (sorted set--- ordered collection), and hash (hash type). Like memcached, data is cached in memory for efficiency. The difference is that redis periodically writes updated data to disk or writes modification operations to appended record files, and implements master-slave (master-slave) synchronization on this basis.

Redis is a high-performance key-value database. The emergence of redis makes up for the deficiency of key/value storage such as memcacehd to a great extent, and can play a good complementary role to relational database in some cases. It provides clients such as java,C/C++,C#,php,javaScript,Perl,Object-C,python,Ruby, which is easy to use.

If you simply compare the difference between redis and memcached, there are basically the following three points:

1Regent Redis not only supports simple key/value type data, but also provides storage of data structures such as list,set,zset,hash.

2DireRedis supports data backup, that is, data backup in master-slave mode.

3GradeRedis supports data persistence, which can keep the data in memory on disk and can be loaded and used again when rebooting.

In Reids, not all data is stored in memory all the time. This is the biggest difference compared with memcacehd.

Redis only caches all key information. If Reids finds that the memory usage exceeds a certain threshold, it will trigger the operation of swap, and Redis calculates that those value corresponding to key need to swap to disk based on "swappability = age*log (size_in_memory)". The value corresponding to these key is then persisted to disk and cleared in memory. This feature allows redis to store more data than its machine's own memory. Of course, the machine's own memory must be able to maintain all the eky, because the data will not be swap operations.

When reading data from Redis, if the value corresponding to the read key is no longer in memory, then the Redis needs to load the corresponding data from the swap file and then return it to the requester.

Comparison between memcached and redis

1. Network IO model

Memcacehd is a multithreaded, non-blocking IO reuse network model, which is divided into listening main thread and worker sub-thread. The listening thread listens to the network connection, and after receiving the request, the connection description word pipe is passed to the worker thread to read and write IO. The network layer uses the event library encapsulated by libevent, and the multi-thread model can play a multi-core role.

Redis uses a single-threaded IO reuse model and encapsulates a simple AeEvent event handling framework, which mainly implements epoll,kqueue and select. For simple IO operations, single thread can maximize the speed advantage, but Redis also provides some simple computing functions, such as sorting, aggregation, etc., for these operations, the single-threaded model will seriously affect the overall throughput. The entire IO dispatch is blocked.

2. Memory management

Memcacehd uses pre-allocated memory pools, uses slab and different sizes of chunk to manage memory, and value selects the appropriate chunk storage according to the size.

Redis uses on-site memory requests to store data.

3, storage mode and other aspects

Memcached basically only supports simple key-value storage and does not support functions such as persistence and replication. Redis supports many data structures such as list,set,sortedset,hash in addition to key/value.

Second, how to maintain a session session

At present, in order to enable web to adapt to large-scale access, it is necessary to implement the cluster deployment of applications. The most effective solution of the cluster is load balancing, and to achieve load balancing, every user request may be assigned to a non-fixed server, so we must first solve the unity of session to ensure the normal use of users no matter which server the user's request is forwarded to, that is, we need to implement the sharing mechanism of session.

There are several solutions to achieve session unification under the cluster system:

1. Request for precise location (sessionsticky)

For example, the hash policy based on accessing ip, that is, the current user's requests are centrally defined in a single server, so that a single server stores the user's session login information. If the server is down, it is equivalent to a single point of deployment, which will be lost and the session will not be replicated. (not used)

2 sessionreplication session replication sharing:

For example, tomcat comes with session sharing, which mainly refers to the synchronization of session among multiple application servers in a cluster environment to make the session consistent and transparent. If one of the servers fails, according to the principle of load balancing, the scheduler will traverse to find available nodes and distribute requests. Because the session has been synchronized, it can ensure that the user's session information will not be lost and session replication.

Inadequacies of this scheme:

Must be done between the same kind of middleware (e. G. between tomcat-tomcat)

The performance loss caused by session replication will increase rapidly, especially when large objects are saved in session, and the objects change rapidly, the performance degradation is more significant, which will consume system performance. This feature limits the horizontal expansion of web applications.

Session content is synchronized to members through broadcasting, which will cause network traffic bottlenecks, even intranet bottlenecks. The performance is not good under the big concurrency.

3. Session sharing based on cache DB cache

For session sharing based on memcache/redis cache, even if cacheDB is used to store session information, the application server accepts new requests to save session information in cacheDB. When the application server fails, the scheduler will traverse to find available nodes and distribute the request. When the application server finds that session is not in local memory, it looks for it in cacheDB, and if found, it copies it to the local machine, thus realizing session sharing and high availability. (recommended)

Third, nginx+tomcat+redis+mysql implements session sharing, load balancing 1, project environment host operating system ip address nginxCentOS 7.3172.16.1.100tomcat-1CentOS 7.3172.16.1.110tomcat-2CentOS 7.3172.16.1.120mysqlCentOS 7.3172.16.1.130RedisCentOS 7.3172.16.1.302, project topology

In this figure, nginx acts as a reverse proxy to achieve static and dynamic separation, randomly assigning customer dynamic requests to two tomcat servers according to weight, with redis as the shared session data server for two tomcat and mysql as the back-end database for two tomcat.

3, project implementation

1Direc nginx installation configuration

Using nginx as the load balancer of tomcat, the session session data of tomcat is stored in redis, which can achieve the 7x24 effect of zero downtime. Because the session is stored in redis, nginx does not have to configure what is called stick pasting a certain tomcat way, so that multiple tomcat load balancing in the background can be realized.

1) install dependency toolkit: [root@nginx ~] # yum-y install gcc* pcre-devel openssl-devel zlib-devel make vim 2) create nginx program user groups and users: [root@nginx ~] # groupadd-r nginx & & useradd-r-g nginx- s / bin/false-M nginx3) compile and install nginx: [root@nginx ~] # tar zxf nginx-1.8.0.tar.gz [root@nginx ~] # cd nginx-1.8.0 [ Root@nginx nginx-1.8.0] #. / configure-- prefix=/usr/local/nginx-- user=nginx-- group=nginx\ >-- with-http_stub_status_module-- with-http_ssl_module-- with-http_dav_module-- with-http_flv_module\ >-- with-http_mp4_module-- with-http_gzip_static_module-- with-http_gzip_static_module\ >-- with-http_addition_module- -with-http_sub_module-- with-pcre-- with-http_realip_module [root@nginx nginx-1.8.0] # make & & make install4) optimize the path and check: [root@nginx nginx-1.8.0] # ln-s / usr/local/nginx/sbin/nginx / usr/local/sbin/ [root@nginx nginx-1.8.0] # nginx- tnginx: the configuration file / usr/local/nginx/conf/nginx.conf syntax is oknginx: Configuration file / usr/local/nginx/conf/nginx.conf test is successful5) write a script for the nginx service: [root@nginx nginx-1.8.0] # vim / ETC _ init.dax _ "& > / dev/nullif [$?-eq 0] thenecho" Nginx service already running. "else$PROG-t & > / dev/nullif [$?-eq 0] Then$PROGecho "Nginx service start success." else$PROG-tfifi;;stop) netstat-anplt | grep ": 80" & > / dev/null & & pgrep "nginx" & > / dev/nullif [$?-eq 0] thenkill-s QUIT $(cat $PIDF) echo "Nginx service stop success." elseecho "Nginx service already stop" fi;;restart) $0 stop$0 start Status) netstat-anplt | grep ": 80" & > / dev/null & & pgrep "nginx" & > / dev/nullif [$?-eq 0] thenecho "Nginx service is running." elseecho "Nginx is stop." fi;;reload) netstat-anplt | grep ": 80" & > / dev/null & & pgrep "nginx" & > / dev/nullif [$?-eq 0] then$PROG-t & > / dev/nullif [$?-eq 0] Thenkill-s HUP $(cat $PIDF) echo "reload Nginx config success." else$PROG-tfielseecho "Nginx service is not run." fi *) echo "Usage: $0 {start | stop | restart | reload}" exit 1esac# and add boot nginx: [root@nginx ~] # chkconfig-- add nginx [root@nginx ~] # chkconfig nginx on# launch nginx: [root @ nginx ~] # systemctl daemon-reload [root@nginx ~] # systemctl start nginx [root@nginx ~] # netstat-anput | grep nginxtcp 00 0.0.0.0 restart 80 0.0.0.0 LISTEN 21812/nginx: master

6) configure nginx reverse proxy (reverse proxy + load balancing + health detection)

Note: combine proxy and upstream modules to achieve back-end web load balancing

Realize the health check of the back-end server by combining the ngx_http_proxy_module module and ngx_http_upstream_module module of nginx by default.

[root@nginx ~] # vim / usr/local/nginx/conf/nginx.conf

Add the following configuration item in the http {} field:

# load balance Settings: upstream backend_tomcat {server 172.16.1.110 weight=1 max_fails=2 fail_timeout=10s; server 172.16.1.120 server 8080 weight=1 max_fails=2 fail_timeout=10s;} # http_proxy Settings: proxy_connect_timeout 75; # nginx connection timeout with backend server (proxy connection timeout) proxy_send_timeout 75 # define the data return time of the back-end server, that is, the back-end server must transfer all the data within the specified time, otherwise, nginx will disconnect the connection. Proxy_read_timeout 75; # defines the timeout proxy_buffer_size 4k for reading responses from the back-end server; # sets the size of the buffer (the buffer size is by default equal to the size of a buffer set by the proxy_buffers instruction, but it can also be set to smaller) proxy_buffers 4 32k # set the number of buffers for each connection and the size of each buffer proxy_busy_buffers_size 64k; # buffer size under high load (the default size is twice the size of the single block buffer set by the proxy_buffers instruction) proxy_temp_file_write_size 64k # when the proxy server responds to a temporary file, this option limits the size of the temporary file each time it is written. Explanation: weight: polling weights, which can also be used in ip_hash. The default value is 1max_fails: the number of times the request failed to run. Default is 1. Returns the error defined by the proxy_next_upstream module when the maximum number of times is exceeded. Fail_timeout: there are two meanings, so a maximum of 2 failures are allowed within 10 seconds; second, after 2 failures, no requests are assigned to this server within 10 seconds.

Add to the server module:

# proxy_pass Settings: location ~ *\. (jsp | do) ${# the dynamic request matched will forward the proxy_pass http://backend_tomcat; # request to the server list defined by backend, that is, reverse proxy, corresponding to the upstream load balancer. Proxy_redirect off; # whether to define the redirection rule proxy_set_header Host $host; # allows you to redefine or add the request header proxy_set_header X-Real-IP $remote_addr; # web server to get the real ip of the user, or you can get the proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for through the following X-Forward-For # the backend Web server can obtain the user's real IP proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;# through X-Forwarded-For to increase failover. If the backend server returns errors such as 502,504 or execution timeout, the request will be automatically forwarded to another server in the upstream load balancer pool to achieve failover}

7) restart the nginx service and set firewall rules:

[root@nginx] # systemctl restart nginx [root@nginx] # firewall-cmd-- add-port=80/tcp-- permanentsuccess [root@nginx ~] # firewall-cmd-- reloadsuccess

2. Install and deploy tomcat server

Before installing tomcat, you must install JDK,JDK, which is a java language software development kit provided by sun company free of charge, which includes java virtual machine (JVM). The written java source program can be compiled to form java bytecode. As long as JDK is installed, you can use JVM to interpret these bytecode files, thus ensuring the platform of java.

1) install JDK and configure java environment (tomcat1 and tomcat2 server installation)

[root@tomcat-1 ~] # tar zxf jdk-8u211-linux-x64.tar.gz [root@tomcat-1 ~] # mv jdk1.8.0_211/ / usr/local/ Java [root @ tomcat-1 ~] # vim / etc/profileexport JAVA_HOME=/usr/local/javaexport PATH=$JAVA_HOME/bin:$P ATH [root @ tomcat-1 ~] # source / etc/ profile [root @ tomcat-1 ~] # java-version # ensure that the java version is consistent with the current version java version " 1.8.0211" Java (TM) SE Runtime Environment (build 1.8.0_211-b12) Java HotSpot (TM) 64-Bit Server VM (build 25.211-b12) Mixed mode)

2) install tomcat (tomcat1 and tomcat2 server do the same)

The required version can be downloaded from the tomcat official website: https://tomcat.apache.org

[root@tomcat-1 ~] # tar zxf apache-tomcat-8.5.35.tar.gz [root@tomcat-1 ~] # mv apache-tomcat-8.5.35 / usr/local/ tomcat 8 [root @ tomcat-1 ~] # vim / etc/profileexport CATALINA_HOME=/usr/local/tomcat8export PATH=$JAVA_HOME/bin:$CATALINA_HOME/bin:$ path [root @ tomcat-1 ~] # source / etc/profile# launch tomcat: [root @ tomcat-1 ~] # / usr/local/tomcat8 / bin/startup.sh # this is just showing the path to the startup script Because the environment variable is set above You can directly execute startup.sh script Using CATALINA_BASE: / usr/local/tomcat8Using CATALINA_HOME: / usr/local/tomcat8Using CATALINA_TMPDIR: / usr/local/tomcat8/tempUsing JRE_HOME: / usr/local/javaUsing CLASSPATH: / usr/local/tomcat8/bin/bootstrap.jar:/usr/local/tomcat8/bin/tomcat-juli.jarTomcat started.[ root @ tomcat-1 ~] # netstat-anput | grep 8080tcp6 0 0: :: 8080:: * LISTEN 15408/java# firewall rule configuration: [root@tomcat-1 ~] # firewall-cmd-- add-port=8080/tcp-- implementator [root @ tomcat-1 ~] # firewall-cmd-- reloadsuccess

# browser test access to two tomcat servers

3) modify tomcat configuration files (tomcat1 and tomcat2 operations)

[root@tomcat-1 ~] # vim / usr/local/tomcat8/conf/server.xml# set the default virtual host, add jvmRoute# to modify the default virtual host, and point the website file path to / web/webapp1, add the context segment # to the host segment and add the line content.

# configuration file of tomcat-2 server:

# the configurations of the two machines are only different in jvmRoute, and the other configurations remain the same:

Note: jvmRoute is the jvm logo, that is, the label at the top of the page. In the actual production environment, all backend tomcat logos should be the same. Here, for the demonstration of the experiment, my two tomcat logos are changed to different ones. It will be easy to verify later for verification.

4) create web page directory and test file: (tomcat-1 and tomcat-2 operation are the same)

[root@tomcat-1 ~] # mkdir-p / web/ webapp1 [root @ tomcat-1 ~] # vim / web/webapp1/index.jsp # write dynamic web page file # content is as follows: tomcat-1 Session serviced by tomcatSession IDCreated on

# Note: in order to test the load balance, the title of the index.jsp file of the tomcat-2 node is changed to "tomcat-2" (the web content provided by the two tomcat servers in the production environment is the same), and other configurations are the same.

5) restart the tomct service and verify the load balancing

# both tomcat-1 and tomcat-2 need to restart [root@tomcat-1 ~] # shutdown.sh [root@tomcat-1 ~] # startup.sh [root@tomcat-1 ~] # netstat-anput | grep 8080tcp6 0: 8080: * LISTEN 15551/java

# users use browsers to verify load balancer by accessing nginx web service:

Results of the first visit:

Results of the second visit:

As can be seen from the above results, nginx distributes the access requests to the backend tomcat-1 and tomcat-2 respectively, and the access requests of the client achieve load balancing, but the session id is different (that is, session retention is not implemented), which will cause great pressure on the backend server.

6) verify the health check

# you can shut down a tomcat host, simulate downtime, and use a client browser to test access [root@tomcat-1 ~] # shutdown.sh Using CATALINA_BASE: / usr/local/tomcat8Using CATALINA_HOME: / usr/local/tomcat8Using CATALINA_TMPDIR: / usr/local/tomcat8/tempUsing JRE_HOME: / usr/local/javaUsing CLASSPATH: / usr/local/tomcat8/bin/bootstrap.jar:/usr/local/tomcat8/bin/tomcat-juli.jar

No matter how you refresh the page, tomcat2 always provides the service, indicating that the health check worked and verified successfully.

3. Configure tomcat to implement session persistence through redis

The front can be said to be preparatory work, and the following is the focus of the project.

1) install redis

Download address on the official website: http://download.redis.io/releases/

[root@redis ~] # tar zxf redis-4.0.14.tar.gz

[root@redis ~] # cd redis-4.0.14/

[root@redis redis-4.0.14] # make & & make install

From the figure above, we can easily see that redis is installed in the / usr/local,/usr/local/bin,/usr/local/share,/usr/local/include,/usr/local/lib,/usr/local/share/man directory.

# then change to the utils directory and execute the redis initialization script install_server.sh, as follows:

[root@redis redis-4.0.14] # cd utils/ [root@redis utils] #. / install_server.sh Welcome to the redis service installerThis script will help you easily set up a running redis serverPlease select the redis port for this instance: [6379] Selecting default: 6379Please select the redis config file name [/ etc/redis/6379.conf] Selected default-/ etc/redis/6379.confPlease select the redis log file name [/ var/log/redis_6379.log] Selected default-/ var/log/redis _ 6379.logPlease select the data directory for this instance [/ var/lib/redis/6379] Selected default-/ var/lib/redis/6379Please select the redis executable path [/ usr/local/bin/redis-server] Selected config: Port: 6379 Config file: / etc/redis/6379.conf Log file: / var/log/redis_6379.logData dir: / var/lib/redis/6379Executable: / usr/local/bin/redis-server Cli Executable: / usr/local/bin/redis-cliIs this ok? Then press ENTER to go on or Ctrl-C to abort.Copied / tmp/6379.conf = > / etc/init.d/redis_6379Installing service...Successfully added to chkconfigsuccessful added to runlevels 345 starting Redis server...Installation fulfilling # all of the above default enter

Through the above installation process, we can see that after redis initialization, the redis configuration file is / etc/redis/6379.conf, the log file is / var/log/redis_6379.log, the data file dump.rdb is stored in the / var/lib/redis/6379 directory, and the startup script is / etc/init.d/redis_6379.

# if you need to use systemd, you can create a unit file named redis_6379.service under / etc/systemd/system.

[root@redis utils] # vim / etc/systemd/system/redis_6379.service# is as follows: [Unit] Description=Redis on port 6379 [Service] Type=forkingExecStart=/etc/init.d/redis_6379 startExecStop=/etc/init.d/redis_6379 stop [Install] WantedBy=multi-user.target# Note: here Type=forking is the form of background operation

# start redis

[root@redis utils] # systemctl daemon-reload

[root@redis utils] # systemctl enable redis_6379.service

[root@redis utils] # systemctl start redis_6379.service

# as we can see from the figure above, the service status is dead. The solution is to restart the service, as shown in the following figure:

# Firewall rule settings: [root@redis utils] # firewall-cmd-- add-port=6379/tcp-- permanentsuccess [root@redis utils] # firewall-cmd-- reloadsuccess

2) configure redis

[root@redis ~] # vim / etc/redis/6379.conf # modify the content as follows (remove comments and modify): bind 172.16.1.30 # modify the listening address of redis to iprequirepass pwd@123 of redis host # for security, you need to start the requirepass parameter of the password verification feature of redis. # restart the redis service: [root@redis ~] # systemctl restart redis_ 6379.service [root @ redis ~] # netstat-anput | grep redistcp 0 0172.16.1.30 netstat 6379 0.0.0.0 * LISTEN 12261/redis-server

# after the redis configuration file is configured, start redis and perform a simple operation (test), as follows:

[root@redis] # redis-cli-h 172.16.1.30-p 6379-a pwd@123Warning: Using a password with'- a 'option on the command line interface may not be safe.172.16.1.30:6379 > keys * (empty list or set) 172.16.1.30 Using a password with 6379 > set name lisiOK172.16.1.30:6379 > get name "lisi" 172.16.1.30 quit

The above parameters explain:

First of all, we use redis's command line tool redis-cli to connect to the redis server. Ip is 172.16.1.30 (tested locally here). The port is 6379 and the password is pwd@123keys *: is to view all the key values of redis pair set nam lisi: add a key (name)-value (lisi) get name: view the contents of the name key quit: exit the connection # redis other operation commands, which will be explained later

At this point, all the deployment of redis is complete, and the next step is to configure session synchronization for tomcat.

3) configure tomcat session redis synchronization (tomcat1 and tomcat2 operations are the same)

# download the corresponding jar package for tomcat-redis-session-manager. There are three main packages:

After the tomcat85-session-redis-1.0.jarjedis-2.9.0.jarcommons-pool2-2.4.2.jar ① is downloaded, copy it to the $TOMCAT_HOME/lib directory: [root@tomcat-1 ~] # cp tomcat85-session-redis-1.0.jarjedis-2.9.0.jarcommons-pool2-2.4.2.jar / usr/local/tomcat8/lib/ ② modify tomcat's context.xml file: [root@tomcat-1 ~ ] # vim / usr/local/tomcat8/conf/context.xml add the following:

The content in the figure is as follows:

# session expiration time (in s) ③ has been modified, restart tomcat: [root @ tomcat-1 ~] # shutdown.sh [root@tomcat-1 ~] # startup.sh [root@tomcat-1 ~] # netstat-anput | grep 8080tcp6 0: 8080: * LISTEN 16931/java

Repeat on the tomcat-2 host.

④ verifies that the session session is consistent

# simulate users to access the http://172.16.1.100/index.jsp test page through a browser

First visit:

Second visit (refresh page):

As you can see, different tomcat are visited, but the session is the same, indicating that the session session is synchronized, achieving the purpose of the cluster.

Note: starting from tomcat6, the session persistence setting is enabled by default. You can disable local session persistence during testing. In fact, it is also very simple. In the context.xml file under the conf directory of tomcat, uncomment the following configuration:

# before modification: # after modification: ⑤ View redis: [root @ redis ~] # redis-cli-h 172.16.1.30-p 6379-a pwd@123Warning: Using a password with'- a 'option on the command line interface may not be safe.172.16.1.30:6379 > keys * 1) "3585F7426EBBC83802C0407575FEAC72tMLrlI.tomcat-2" 2) "name" 172.16.1.306379 > quit

As you can see, redis establishes key-value pairs for session session persistence on tomcat2.

4. Configure tomcat to connect to the database

Tomcat's session session persistence solved this problem through redis, and now it's time to solve the tomcat connection database problem. (host 172.16.1.130 serves as a mysql DB server)

1) install mysql service (binary mode)

[root@mysql ~] # vim mysql5.7. Nodepsfitar zxf mysql-5.7.28-linux-glibc2.12-x86_64.tar.gz mv mysql-5.7.28-linux-glibc2.12-x86_64 usr/local/mysqlln / usr/local/mysql/bin/* / usr/local/bingroupadd-r mysql & & grep mariadb & > / dev/nullif [$?-eq 0] then rpm-e mysql-- nodepsfitar zxf mysql-5.7.28-linux-glibc2.12-x86_64.tar.gz mv mysql-5.7.28-linux-glibc2.12-x86_64 / usr/local/mysqlln-s / usr/local/mysql/bin/* / usr/local/bingroupadd-r mysql & & Useradd-r-g mysql-s / bin/false-M mysqlmkdir / usr/local/mysql/datachown-R mysql:mysql / usr/local/mysqlcat > / etc/my.cnf flush privileges Query OK, 0 rows affected (0.00 sec) mysql > create database javadb; / / create library Query OK, 1 row affected (0.00 sec) mysql > use javadbDatabase changedmysql > create table testtb (id int primary key auto_increment,-> name varchar (25),-> age int (3)) / / create table Query OK, 0 rows affected (0.00 sec) mysql > insert into testtb (name,age) values ('zhangsan','20'), (' lisi','21'), ('sunqian','22'); / / insert data Query OK, 3 rows affected (0.00 sec) Records: 3 Duplicates: 0 Warnings: 0mysql > select * from testtb # check +-+ | id | name | age | +-+ | 1 | zhangsan | 20 | 2 | lisi | 21 | 3 | sunqian | 22 | +-+ 3 rows in set (0.00 sec)

3) configure the tomcat server to connect to the mysql database (both tomcat operate in the same way)

(1) download mysql-connector-java-5.1.22-bin.jar and copy it to the $CATALINA_HOME/lib directory: [root@tomcat-1 ~] # cp mysql-connector-java-5.1.22.jar / usr/local/tomcat8/lib/ (2) Context file settings: [root@tomcat-1 ~] # vim / usr/local/tomcat8/conf/context.xml

# the content added in the above figure is as follows:

(3) create a new directory under the / web/webapp1/ root directory to store the website xml configuration files for tomcat to connect to the mysql database

[root@tomcat-1 ~] # mkdir / web/webapp1/WEB-INF [root@tomcat-1 ~] # vim / web/webapp1/WEB-INF/web.xml is added as follows: MySQL Test AppDB Connectionjdbc/TestDBjavax.sql.DataSourceContainer# saves changes and exits Restart the tomcat service: [root@tomcat-1 ~] # shutdown.sh Using CATALINA_BASE: / usr/local/tomcat8Using CATALINA_HOME: / usr/local/tomcat8Using CATALINA_TMPDIR: / usr/local/tomcat8/tempUsing JRE_HOME: / usr/local/javaUsing CLASSPATH: / usr/local/tomcat8/bin/bootstrap.jar:/usr/local/tomcat8/bin/tomcat-juli.jar [root@tomcat-1 ~] # startup.sh Using CATALINA_BASE: / usr/local/tomcat8Using CATALINA_HOME: / usr/local/tomcat8Using CATALINA_TMPDIR: / usr/local/tomcat8/tempUsing JRE_HOME: / usr/local/javaUsing CLASSPATH: / usr/local/tomcat8/bin/bootstrap.jar:/usr/local/tomcat8/bin/tomcat-juli.jarTomcat started.

Tomcat-2 does the same thing as tomcat-1.

(4) Test code

# now create a simple test .jsp page to test the connectivity of tomcat and mysql

[root@tomcat-1 ~] # vim / web/webapp1/test.jsp# is as follows: (modify the corresponding parameters according to your environment) MySQLconnect MySQL

Note: create the same test code on the tomcat-2 node, but for better verification, change the title to "MySQL-2".

(5) access the test page through the browser, URL: http://172.16.1.100/test.jsp, or the tomcat server that proxies the backend through nginx.

As you can see from the figure above, tomcat-1 and tomcat-2 can now connect to the database.

At this point, the project has been built.

Installation package and jar package have been uploaded to the network disk: link: https://pan.baidu.com/s/133H7oEbBWiBvaNWUoFgH3Q

Extraction code: 2fj1

The above is the nginx+tomcat+redis+mysql to achieve session session technology sharing made a brief introduction, of course, the detailed use of the above differences also need to be used by everyone to understand. If you want to know more, welcome to follow the industry information channel!

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