WSO2项目RabbitMQ消息存储初始化失败：x-queue-type参数不匹配

问题场景 #

在WSO2项目中，使用以下RabbitMQ消息存储配置：

<messageStore class="org.apache.synapse.message.store.impl.rabbitmq.RabbitMQStore" name="EmailErrorPendingMS" xmlns="http://ws.apache.org/ns/synapse">
    <parameter name="store.rabbitmq.host.name">rabbitmq-staging</parameter>
    <parameter name="store.producer.guaranteed.delivery.enable">false</parameter>
    <parameter name="store.rabbitmq.host.port">5672</parameter>
    <parameter name="store.rabbitmq.route.key">email.key</parameter>
    <parameter name="store.rabbitmq.username">guest</parameter>
    <parameter name="store.rabbitmq.virtual.host">Email</parameter>
    <parameter name="rabbitmq.connection.ssl.enabled">false</parameter>
    <parameter name="store.rabbitmq.exchange.name">email.exchange</parameter>
    <parameter name="store.rabbitmq.queue.name">email.queue</parameter>
    <parameter name="store.rabbitmq.password">guest</parameter>
</messageStore>

运行项目时出现初始化失败，核心错误提示：

虚拟主机'Email'中的队列'email.queue'的x-queue-type参数不匹配，收到的值为none，但当前队列该参数值为类型longstr的'quorum'

完整异常栈信息：

INFO {org.apache.synapse.config.xml.MessageStoreFactory} - Successfully added Message Store configuration of : [EmailMS].
INFO {org.apache.synapse.message.store.impl.rabbitmq.RabbitMQStore} - Store [EmailMS] Successfully connected to RabbitMQ Broker
ERROR {org.apache.synapse.message.store.impl.rabbitmq.RabbitMQStore} - Store [EmailMS]. Initialization failed... java.io.IOException
    at com.rabbitmq.client.impl.AMQChannel.wrap(AMQChannel.java:129)
    at com.rabbitmq.client.impl.AMQChannel.wrap(AMQChannel.java:125)
    at com.rabbitmq.client.impl.AMQChannel.exnWrappingRpc(AMQChannel.java:147)
    at com.rabbitmq.client.impl.ChannelN.queueDeclare(ChannelN.java:968)
    at com.rabbitmq.client.impl.recovery.AutorecoveringChannel.queueDeclare(AutorecoveringChannel.java:333)
    at org.apache.synapse.message.store.impl.rabbitmq.RabbitMQStore.declareQueue(RabbitMQStore.java:308)
    at org.apache.synapse.message.store.impl.rabbitmq.RabbitMQStore.init(RabbitMQStore.java:125)
    ...
Suppressed: com.rabbitmq.client.AlreadyClosedException: channel is already closed due to channel error; protocol method: #method<channel.close>(reply-code=406, reply-text=PRECONDITION_FAILED - inequivalent arg 'x-queue-type' for queue 'email.queue' in vhost 'Email': received none but current is the value 'quorum' of type 'longstr', class-id=50, method-id=10)
    ...
Caused by: com.rabbitmq.client.ShutdownSignalException: channel error; protocol method: #method<channel.close>(reply-code=406, reply-text=PRECONDITION_FAILED - inequivalent arg 'x-queue-type' for queue 'email.queue' in vhost 'Email': received none but current is the value 'quorum' of type 'longstr', class-id=50, method-id=10)
    ...

解决方案 #

方法一：修改WSO2配置匹配已存在队列类型 #

在现有消息存储配置中添加队列类型参数，让WSO2初始化时使用与RabbitMQ中已存在队列一致的x-queue-type值，修改后的完整配置如下：

<messageStore class="org.apache.synapse.message.store.impl.rabbitmq.RabbitMQStore" name="EmailErrorPendingMS" xmlns="http://ws.apache.org/ns/synapse">
    <parameter name="store.rabbitmq.host.name">rabbitmq-staging</parameter>
    <parameter name="store.producer.guaranteed.delivery.enable">false</parameter>
    <parameter name="store.rabbitmq.host.port">5672</parameter>
    <parameter name="store.rabbitmq.route.key">email.key</parameter>
    <parameter name="store.rabbitmq.username">guest</parameter>
    <parameter name="store.rabbitmq.virtual.host">Email</parameter>
    <parameter name="rabbitmq.connection.ssl.enabled">false</parameter>
    <parameter name="store.rabbitmq.exchange.name">email.exchange</parameter>
    <parameter name="store.rabbitmq.queue.name">email.queue</parameter>
    <parameter name="store.rabbitmq.password">guest</parameter>
    <!-- 添加队列类型参数，匹配已存在的quorum队列 -->
    <parameter name="store.rabbitmq.queue.x-queue-type">quorum</parameter>
</messageStore>

方法二：删除RabbitMQ中已存在队列（注意数据风险） #

若队列中的数据可丢弃或已完成备份，可通过RabbitMQ管理界面或命令行删除Email虚拟主机下的email.queue队列，之后重启WSO2服务。WSO2会自动创建符合当前配置的默认类型（classic）队列。

原因说明 #

WSO2的RabbitMQStore组件初始化时，会调用RabbitMQ客户端的queueDeclare方法声明队列，默认不指定x-queue-type参数；而RabbitMQ中已存在的email.queue队列是quorum类型，参数不匹配时RabbitMQ会返回406预条件失败错误，导致初始化失败。

内容的提问来源于stack exchange，提问作者Mahmoud Saleh