Web Sessions Installation
展示不使用Terracotta DSO如何集群Web Sessions。
1、要求
1）jdk1.6或者更高版本
2）Terracotta 3.7或者更高版本
3）所有被集群的对象需要实现序列化，如果不想实现序列化，必须使用Terracotta DSO定制Web Sessions的安装
2、安装Terracotta Sessions jar
1）为保证兼容性，请使用已安装的Terracotta的jar文件
2）为了使应用的web Sessions在集群中共享，添加下列jar文件到应用服务器的的lib目录中
${TERRACOTTA_HOME}/sessions/terracotta-session-<version>.jar
${TERRACOTTA_HOME} 是指Terracotta的安装目录，<version>是指当前使用的terracotta session的版本，我这里就是D:/terracotta/terracotta-3.7.2/sessions/terracotta- session-1.3.1.jar。
${TERRACOTTA_HOME}/common/terracotta-toolkit-<API-version>-runtime-ee-<version>.jar
The Terracotta Toolkit JAR包含了Terracotta客户端类库，<API-version> 就是指Terracotta Toolkit API version. <version>就是当前使用的Terracotta Toolkit JAR版本，我这里就是：D:/terracotta/terracotta-3.7.2/common/terracotta-toolkit- 1.6-runtime-5.2.0.jar
3）上述session和toolkit的jar文件在各种应用服务器中的存放路径
| Application Server | Suggested Location for Terracotta Sessions JAR File |
|---|---|
| JBoss AS (earlier than 6.0) | < jboss install dir>/lib |
| JBoss AS 6.0 | < jboss install dir>/common/lib (REQUIRED) |
| JBoss AS 7.0 or 7.1 | < jboss install dir>/WEB-INF/lib |
| Jetty | WEB-INF/lib |
| Tomcat 5.0 and 5.5 | $CATALINA_HOME/server/lib |
| Tomcat 6.0 and 7.0 | $CATALINA_HOME/lib |
| WebLogic | WEB-INF/lib |
3、配置web-session集群
1）Terracotta servers和Terracotta clients通过 Terracotta配置文件运行在集群中的应用服务器上，默认的配置文件是tc-config.xml，服务器启动的时候不指定配置文件就默认使用 tc-config.xml。
2）为了把Terracotta集群添加到我们的应用中，需要通过web.xml或者context.xml文件指定Terracotta clients如何获取配置。
3）Jetty, WebLogic, and WebSphere需要添加以下配置到web.xml文件中
<filter> <filter-name>terracotta</filter-name> <!-- The filter class is specific to the application server. --> <filter-class>org.terracotta.session.{container-specific-class}</filter-class> <init-param> <param-name>tcConfigUrl</param-name> <!-- <init-param> of type tcConfigUrl has a <param-value> element containing the URL or filepath (for example, /lib/tc-config.xml) to tc-config.xml. If the Terracotta configuration source changes at a later time, it must be updated in configuration. --> <param-value>localhost:9510</param-value> </init-param> </filter> <filter-mapping> <!-- Must match filter name from above. --> <filter-name>terracotta</filter-name> <url-pattern>/*</url-pattern> <!-- Enable all available dispatchers. --> <dispatcher>ERROR</dispatcher> <dispatcher>INCLUDE</dispatcher> <dispatcher>FORWARD</dispatcher> <dispatcher>REQUEST</dispatcher> </filter-mapping>
<filter-class>中的{container-specific-class}根据实际的应用服务器类型选择：
| Container | Value of <filter-class> |
|---|---|
| Jetty 6.1 | org.terracotta.session.TerracottaJetty61xSessionFilter |
| Jetty 7.4.1 | org.terracotta.session.TerracottaJetty74xSessionFilter |
| WebLogic 9 | org.terracotta.session.TerracottaWeblogic9xSessionFilter |
| WebLogic 10 | org.terracotta.session.TerracottaWeblogic10xSessionFilter |
| WebSphere 6.1 | org.terracotta.session.TerracottaWebsphere61xSessionFilter |
| WebSphere 7.0 | org.terracotta.session.TerracottaWebsphere70xSessionFilter |
4）Tomcat and JBoss AS 6.0 or Earlier
使用war包发布的应用，如果是tomcat，确保context.xml文件在/META-INF目录下，如果是JBoss，确保context.xml文件在/WEB-INF目录下。
context.xml文件内容如下：
<Valve className="org.terracotta.session.{container-specific-class}" tcConfigUrl="localhost:9510"/>
{container-specific-class}根据实际的应用服务器类型选择：
| Container | Value of className |
|---|---|
| JBoss Application Server 4.0 | org.terracotta.session.TerracottaJboss40xSessionValve |
| JBoss Application Server 4.2 | org.terracotta.session.TerracottaJboss42xSessionValve |
| JBoss Application Server 5.1 | org.terracotta.session.TerracottaJboss51xSessionValve |
| JBoss Application Server 6.0 | org.terracotta.session.TerracottaJboss60xSessionValve |
| Tomcat 5.0 | org.terracotta.session.TerracottaTomcat50xSessionValve |
| Tomcat 5.5 | org.terracotta.session.TerracottaTomcat55xSessionValve |
| Tomcat 6.0 | org.terracotta.session.TerracottaTomcat60xSessionValve |
| Tomcat 7.0 | org.terracotta.session.TerracottaTomcat70xSessionValve |
例如在tomcat6.0中，context.xml内容如下：
<Context> <Valve className="org.terracotta.session.TerracottaTomcat60xSessionValve" tcConfigUrl="localhost:9510"/>
</Context>
确保Terracotta Value是context.xml文件中的第一个<Value>元素。
如果在tomcat中使用了authenticator，在Terracotta集群运行的时候有可能会遇到UnsupportedOperationException，在tomcat5.5以上可以禁用changeSessionIdOnAuthentication来防止这种错误：
<Valve changeSessionIdOnAuthentication="false" className="org.apache.catalina.authenticator.BasicAuthenticator"/>
5）JBoss7.0 or 7.1
添加以下内容到WEB-INF/jboss-web.xml中
<?xml version="1.0" encoding="UTF-8"?><jboss-web>... <valve> <class-name>org.terracotta.session.TerracottaJboss7xSessionValve</class-name> <param> <param-name>tcConfigUrl</param-name>
<param-value>localhost:9510</param-value> </param> </valve>...</jboss-web>
4、启动集群
1）启动 Terracotta server:
UNIX/Linux
${TERRACOTTA_HOME}/bin/start-tc-server.sh &
Microsoft Windows
${TERRACOTTA_HOME}/bin/start-tc-server.bat
2）启动应用服务器
3）启动Terracotta 控制台
UNIX/Linux
${TERRACOTTA_HOME}/bin/dev-console.sh &
Microsoft Windows
${TERRACOTTA_HOME}/bin/dev-console.bat
4）启动控制台后，可以看到集群中Terracotta Server和客户端
5、Terracotta配置
这里配置展示如何在分开的机器上运行服务器和客户端，增加容灾（高可用性），扩展集群和添加高可用性可以按照下面的步骤：
- Moving the Terracotta server to its own machine
- Creating a cluster with multiple Terracotta servers
- Creating multiple application nodes
1）关闭Terracotta Cluster
2）创建Terracotta配置文件tc-config.xml：
<tc:tc-config>
<servers> <!-- Sets where the Terracotta server can be found. Replace the value of host with the server's IP address. --> <server host="server.1.ip.address" name="Server1"> <data>%(user.home)/terracotta/server-data</data> <logs>%(user.home)/terracotta/server-logs</logs> </server> <!-- If using a standby Terracotta server, also referred to as an ACTIVE-PASSIVE configuration, add the second server here. --> <server host="server.2.ip.address" name="Server2"> <data>%(user.home)/terracotta/server-data</data> <logs>%(user.home)/terracotta/server-logs</logs> </server> <!-- If using more than one server, add an <ha> section. --> <ha> <mode>networked-active-passive</mode> <networked-active-passive> <election-time>5</election-time> </networked-active-passive> </ha></servers> <!-- Sets where the generated client logs are saved on clients. -->
<clients> <logs>%(user.home)/terracotta/client-logs</logs></clients></tc:tc-config>
3）在tc-config.xml中配置的每一台服务器机器上安装terracotta3.7.2
4）把tc-config.xml文件复制到每一台服务器中的terracotta Server可以访问的位置
5）在每一台服务器中按照上面步骤（2、安装Terracotta Sessions jar）安装Terracotta Sessions jar
6）在每一台应用服务器中配置web.xml或者context.xml
如果使用的是web.xml，按如下配置：
<param-value>server.1.ip.address:9510,server.2.ip.address:9510</param-value>
如果使用的是context.xml，按如下配置：
tcConfigUrl="server.1.ip.address:9510,server.2.ip.address:9510"
tc-config.xml中配置了多少台服务器，web.xml或者context.xml就要配置多少。
7）启动Terracotta Server
UNIX/Linux
${TERRACOTTA_HOME}/bin/start-tc-server.sh -f <path/to/tc-config.xml> -n Server1 &
Microsoft Windows
${TERRACOTTA_HOME}/bin/start-tc-server.bat -f <path/to/tc-config.xml> -n Server1
${TERRACOTTA_HOME}是指terracotta的安装目录
<path/to/tc-config.xml>是指tc-config.xml文件的完整存放路径
Server1是指在tc-config.xml文件中配置的ServerName
在每一台服务器上启动各自的Terracotta Server，注意启动的时候 -n 指定各自的ServerName，第二台和往后启动的Terracotta Server处于备用状态。
8）在每一台服务器上启动各自的应用服务器
9）启动Terracotta控制台查看集群