目前公司需要對當前的業務進行微服務化改造，經過討論選擇使用用dubbo進行服務治理，並在我的業務功能模塊中進行試點，由於之前寫過dubbo相關的demo，基礎知識就不再重復了，demo地址：
https://github.com/liujifei/dubbo.git
工程的基本搭建參照了另一篇博客，寫的十分詳盡，推薦一下：
Maven多模塊，Dubbo分布式服務框架，SpringMVC，前后端分離項目，基礎搭建，搭建過程出現的問題
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基本配置完成之后，當使用組播的方式時沒有發現問題，服務提供方和調用方都正常，當使用zk集群作為注冊中心時，項目啟動報錯：
java.lang.NoClassDefFoundError: org/apache/curator/shaded/com/google/common/cache/CacheBuilder
處理方法：
在parent的pom.xml中dependencyManagement加入
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>2.11.0</version>
</dependency>
子module的pom.xml中加入
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
</dependency>
問題解決。
另附zk集群配置方法：
<
dubbo:registry
address
=
"zookeeper://10.20.153.10:2181?backup=10.20.153.11:2181,10.20.153.12:2181"
/>
|
或
<
dubbo:registry
protocol
=
"zookeeper"
address
=
"10.20.153.10:2181,10.20.153.11:2181,10.20.153.12:2181"
/>
|
同中心多組的配置方法：
<
dubbo:registry
id
=
"chinaRegistry"
protocol
=
"zookeeper"
address
=
"10.20.153.10:2181"
group
=
"china"
/>
<
dubbo:registry
id
=
"intlRegistry"
protocol
=
"zookeeper"
address
=
"10.20.153.10:2181"
group
=
"intl"
/>
|
若遇到其他問題再記錄
2018-04-12 11:05:16
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上面的provider搞定了，之后就是consumer。之前的調用方式是簡單的sdk調用，服務化之后，需要將原web工程改造為dubbo調用方。
具體改造內容很簡單主要包括兩個文件：
1、pom.xml
<properties>
<!-- dubbo -->
<dubbo.version>2.6.1</dubbo.version>
</properties>
<!-- dubbo相關依賴 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>${dubbo.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo-rpc-dubbo</artifactId>
<version>${dubbo.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo-registry-api</artifactId>
<version>${dubbo.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo-registry-zookeeper</artifactId>
<version>${dubbo.version}</version>
</dependency>
另外添加服務提供方api的依賴
2、spring-context.xml
- beans的namespace添加 xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"；xsi:schemaLocation中添加
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd - 文件內容中添加
<dubbo:application name="***" />
<dubbo:registry address="***" />
<dubbo:reference id="***" check="false" interface="***"/>
回調：
當provider需要調用consumer中的回調方法時，首先需要在provider的配置文件中修改如下：
<dubbo:service interface="com.***.quality.api.QualityService" ref="qualityService" protocol="dubbo">
<dubbo:method name="excuteJob" >
<dubbo:argument index="1" callback="true" type="com.inspur.quality.api.CallBack"/>
</dubbo:method>
</dubbo:service>
另外需要注意的是，callback作為調用方實現的回調方法，其中不要包含需要dubbo來序列化的對象以及調用其方法，否則會報如下錯誤：
com.alibaba.dubbo.remoting.RemotingException: Fail to decode request due to: RpcInvocation
如：
qualityService.excuteJob(job); // 生產報告 qualityService.productReport(new CallBack() { @Override public void productReport(String dataBaseName, RuleResult[] result, String jobId, String instanceId) { Long time = System.currentTimeMillis(); for(RuleResult single : result){ StringBuilder sqlB = new StringBuilder(); sqlB.append("insert into "); sqlB.append(RESULT_TABLE); sqlB.append(" (RESULTID,JOBID,INSTANCEID,CHECKID,RESULT) VALUES ( '"); sqlB.append(UUID.randomUUID().toString()); sqlB.append("','"); sqlB.append(jobId); sqlB.append("','"); sqlB.append(instanceId); sqlB.append("','"); sqlB.append(single.getRule().getRuleName()); sqlB.append("','"); sqlB.append(single.getResultNumber()); sqlB.append("')"); JdbcUtil.exeSql(dataBaseName, sqlB.toString()); } } }, dataSources[2]);
需要改成
qualityService.excuteJob(job, new CallBack() { /** * @Field @serialVersionUID : TODO */ private static final long serialVersionUID = -5914504806295102148L; @Override public String productReport(String dataBaseName, RuleResult[] result, String jobId, String instanceId) { Long time = System.currentTimeMillis(); StringBuilder sqlB = new StringBuilder(); for(RuleResult single : result){ sqlB.append("insert into "); sqlB.append("QUALITY_RESULT"); sqlB.append(" (RESULTID,JOBID,INSTANCEID,CHECKID,RESULT) VALUES ( '"); sqlB.append(UUID.randomUUID().toString()); sqlB.append("','"); sqlB.append(jobId); sqlB.append("','"); sqlB.append(instanceId); sqlB.append("','"); sqlB.append(single.getRule().getRuleName()); sqlB.append("','"); sqlB.append(single.getResultNumber()); sqlB.append("')"); } return sqlB.toString(); } }, dataSources[2]);
2018-04-18 15:14:13
=====================================================================================
java.lang.NoSuchMethodError: org.apache.curator.utils.ZKPaths.fixForNamespace
問題原因：curator-framework版本為2.11.0與原項目中的包有沖突，改為原項目中的版本2.6.0后，問題解決。
2018-04-23 15:46:31
=====================================================================================
代碼的改造進行完之后，調用時發現報錯如下：
服務提供方報錯：
Caused by: com.alibaba.dubbo.remoting.RemotingException: com.alibaba.com.caucho.hessian.io.HessianProtocolException: 'com.***.quality.rule.MultiCountRule' could not be instantiated
com.alibaba.com.caucho.hessian.io.HessianProtocolException: 'com.***.quality.rule.MultiCountRule' could not be instantiated
Caused by: java.lang.reflect.InvocationTargetException
Caused by: java.lang.NullPointerException
at com.***.quality.rule.MultiCountRule.<init>(MultiCountRule.java:27)
服務調用方報錯：
com.alibaba.dubbo.rpc.RpcException: Failed to invoke the method excuteJob in the service com.***.quality.api.QualityService. Tried 3 times of the providers [192.168.138.1:20880] (1/1) from the registry 172.22.5.2:2181 on the consumer 192.168.138.1 using the dubbo version 2.6.1. Last error is: Failed to invoke remote method: excuteJob, provider: dubbo://192.168.138.1:20880/com.***.quality.api.QualityService?anyhost=true&application=crawlManage&check=false&dubbo=2.6.1&excuteJob.1.callback=true&generic=false&interface=com.***.quality.api.QualityService&methods=newExpectCountRule,registDataSource,newNotNullRule,newMultiCountRule,newPatternRule,newUniqueRule,excuteJob,newIntegrityRule,newDataCountRule&pid=115308®ister.ip=192.168.138.1&remote.timestamp=1524468008733&revision=0.0.1-SNAPSHOT&side=consumer×tamp=1524468416127, cause: Fail to decode request due to: RpcInvocation [methodName=excuteJob, parameterTypes=[class com.***.quality.common.QualityCheckJob, interface com.***.quality.api.CallBack, class java.lang.String], arguments=null, attachments={path=com.***.quality.api.QualityService, input=3355, dubbo=2.6.1, version=0.0.0}]
com.alibaba.dubbo.rpc.RpcException: Failed to invoke the method newMultiCountRule in the service com.***.quality.api.QualityService. Tried 3 times of the providers ......
Caused by: com.alibaba.dubbo.remoting.RemotingException: Fail to decode request due to: RpcInvocation [methodName=excuteJob, parameterTypes=[class com.***.quality.common.QualityCheckJob, interface com.***.quality.api.CallBack, class java.lang.String], arguments=null, attachments={path=com.***.quality.api.QualityService, input=3355, dubbo=2.6.1, version=0.0.0}]
問題是由於參數excuteJob中的屬性MultiCountRule的類中沒有默認構造方法，導致hessian不能正確序列化。
qualityService.productReport(new CallBack() {
/** * @Field @serialVersionUID : TODO */ private static final long serialVersionUID = -5914504806295102148L;
@Override public void productReport(String dataBaseName, RuleResult[] result, String jobId, String instanceId) { Long time = System.currentTimeMillis(); for(RuleResult single : result){ StringBuilder sqlB = new StringBuilder(); sqlB.append("insert into "); sqlB.append("QUALITY_RESULT"); sqlB.append(" (RESULTID,JOBID,INSTANCEID,CHECKID,RESULT) VALUES ( '"); sqlB.append(UUID.randomUUID().toString()); sqlB.append("','"); sqlB.append(jobId); sqlB.append("','"); sqlB.append(instanceId); sqlB.append("','"); sqlB.append(single.getRule().getRuleName()); sqlB.append("','"); sqlB.append(single.getResultNumber()); sqlB.append("')"); JdbcUtil.exeSql(dataBaseName, sqlB.toString()); } } }, dataSources[2]);