Coherence的NameService

Coherence*Extend模式下客户端需要连接一个或多个proxy Server从而接入集群，在一些比较大型的环境中,Proxy Server往往比较多，一旦修改起来需要修改每个配置文件，在Coherence 12.1.2中推出了NameService的功能，原理如下:

• 启动Coherence集群时，先启动一个NameService的进程(固定port),也可以启动多个
• 所有的客户端指到这个NameService(也可以联到多个),然后由NameService分派一个Proxy Service完成接入
• 这样每个Proxy Server的配置可以比较简单

具体配置如下:

proxy-override.xml

<?xml version="1.0"?>
<!DOCTYPE cache-config SYSTEM "cache-config.dtd">
<cache-config>
<caching-scheme-mapping>
<cache-mapping>
<cache-name>*</cache-name>
<scheme-name>distributed-scheme</scheme-name>
</cache-mapping>
</caching-scheme-mapping>

<caching-schemes>
<!-- Distributed caching scheme. -->
<distributed-scheme>
<scheme-name>distributed-scheme</scheme-name>
<service-name>DistributedCache</service-name>
<thread-count>50</thread-count>
<backup-count>1</backup-count>
<backing-map-scheme>
<local-scheme>
<scheme-name>LocalSizeLimited</scheme-name>
</local-scheme>

</backing-map-scheme>
<autostart>true</autostart>
<local-storage>false</local-storage>
</distributed-scheme>
<local-scheme>
<scheme-name>LocalSizeLimited</scheme-name>
<eviction-policy>LRU</eviction-policy>
<high-units>500</high-units>
<unit-calculator>BINARY</unit-calculator>
<unit-factor>1048576</unit-factor>
<expiry-delay>48h</expiry-delay>
</local-scheme>

<proxy-scheme>
<service-name>ExtendTcpProxyService</service-name>
<thread-count>10</thread-count>
<acceptor-config>
<tcp-acceptor>
</tcp-acceptor>
</acceptor-config>
<load-balancer>proxy</load-balancer>
<autostart>true</autostart>
</proxy-scheme>

</caching-schemes>
</cache-config>

启动nameServer的命令(通过unicast方式启动nameServer)

"%java_exec%" -server -showversion -Dtangosol.coherence.localhost=192.168.0.101 -Dtangosol.coherence.localport=8088 -Dtangosol.coherence.mode=prod -Dtangosol.coherence.management.remote=true -Dtangosol.coherence.management=all %java_opts% -Dtangosol.coherence.cacheconfig=E:\wls12c\coherence\bin\storage-override.xml -cp "%coherence_home%\lib\coherence.jar" com.tangosol.net.DefaultCacheServer %*

启动后的提示

启动一个或多个代理服务器，输出

客户端的schema,client.xml

<?xml version="1.0"?>
<!DOCTYPE cache-config SYSTEM "cache-config.dtd">
<cache-config>
<caching-scheme-mapping>
<cache-mapping>
<cache-name>*</cache-name>
<scheme-name>extend-dist</scheme-name>
</cache-mapping>
</caching-scheme-mapping>

<caching-schemes>
<remote-cache-scheme>
<scheme-name>extend-dist</scheme-name>
<service-name>ExtendTcpCacheService</service-name>
<proxy-service-name>ExtendTcpProxyService</proxy-service-name>
<initiator-config>
<tcp-initiator>
<name-service-addresses>
<socket-address>
<address>192.168.0.101</address>
<port>8088</port>
</socket-address>
</name-service-addresses>
<connect-timeout>10s</connect-timeout>
</tcp-initiator>
<outgoing-message-handler>
<request-timeout>5s</request-timeout>
</outgoing-message-handler>
</initiator-config>
</remote-cache-scheme>
</caching-schemes>
</cache-config>

启动以后，看到请求先到NameService 8088.3,然后分到proxy Server,8089:36095