Question

我从Lagom环境连接到AWS Managed Cassandra Service时遇到问题。这是我尝试过的结果，

（1）Amazon提供了有关从Java代码连接到AWS MCS的说明：

https://docs.aws.amazon.com/fr_fr/mcs/latest/devguide/cqlsh.html#using_java_driver

说明的要点是，您需要安装证书，然后将其传递给JVM，如下所示：

-Djavax.net.ssl.trustStore=path_to_file/cassandra_truststore.jks 
-Djavax.net.ssl.trustStorePassword=amazon

然后，您可以使用任何您选择的Cassandra Java驱动程序。而我的选择是Lagom框架随附的DataStax驱动程序。

这是通过将以下内容添加到build.sbt来完成的：

javaOptions ++= Seq(
  "-Djavax.net.ssl.trustStore=project/cassandra_truststore.jks",
  "-Djavax.net.ssl.trustStorePassword=amazon"
)

// Must enable JVM forking to use javaOptions with runAll.
fork := true

（2）在将Lagom应用程序部署到AWS之前，我想以Dev模式使用它，但是将其连接到AWS MCS而不是嵌入式Cassandra服务器。 Lagom提供了在开发模式下执行此操作的说明：

https://www.lagomframework.com/documentation/1.6.x/scala/CassandraServer.html#Connecting-to-a-locally-running-Cassandra-instance

说明的要点是将以下行添加到build.sbt：

lagomCassandraEnabled in ThisBuild := false
lagomUnmanagedServices in ThisBuild := Map("cas_native" -> "tcp://localhost:9042")

此示例中的URI假定在localhost:9042上运行Cassandra服务器。就我而言，我用cassandra.us-east-1.amazonaws.com:9142代替了。

（3）但是，当我运行sbt runAll时，尝试访问AWS MCS时会超时：

Caused by: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: cassandra.us-east-1.amazonaws.com/3.83.168.143:9142 (com.datastax.driver.core.exceptions.OperationTimedOutException: [cassandra.us-east-1.amazonaws.com/3.83.168.143:9142] Operation timed out))

（4）我通过完全绕过Lagom并仅编写一段非常简单的代码来隔离问题，如下所示：

  System.setProperty("javax.net.ssl.trustStore", "redacted_absolute_file_path/cassandra_truststore.jks")
  System.setProperty("javax.net.ssl.trustStorePassword", "amazon")

  val cluster = Cluster.builder.addContactPoint("cassandra.us-east-1.amazonaws.com").withPort(9142).build()
  val session = cluster.connect()
  session.close()
  cluster.close()

这很简单。但是会发生相同的超时。我在做什么错了？

Answer 1

通过查看AWS MCS Python文档找到了一个解决方案（Java文档对此问题非常沉默）。事实证明，我确实需要配置MCS服务特定的凭据，然后按如下所示在Lagom的application.conf文件中提供它们：

cassandra.default {
  port = 9142

  ssl.truststore {
    path = "path/cassandra_truststore.jks"
    password = "amazon"
  }

  authentication {
    username = "service-specific username"
    password = "service-specific password"
  }
}

cassandra-journal {
  port = ${cassandra.default.port}

  ssl.truststore {
    path = ${cassandra.default.ssl.truststore.path}
    password = ${cassandra.default.ssl.truststore.password}
  }

  authentication {
    username = ${cassandra.default.authentication.username}
    password = ${cassandra.default.authentication.password}
  }
}

cassandra-snapshot-store {
  port = ${cassandra.default.port}

  ssl.truststore {
    path = ${cassandra.default.ssl.truststore.path}
    password = ${cassandra.default.ssl.truststore.password}
  }

  authentication {
    username = ${cassandra.default.authentication.username}
    password = ${cassandra.default.authentication.password}
  }
}

lagom.persistence.read-side.cassandra {
  port = ${cassandra.default.port}

  ssl.truststore {
    path = ${cassandra.default.ssl.truststore.path}
    password = ${cassandra.default.ssl.truststore.password}
  }

  authentication {
    username = ${cassandra.default.authentication.username}
    password = ${cassandra.default.authentication.password}
  }
}

从Lagom连接到AWS Managed Cassandra服务

1 个答案: