小编who*_*ami的帖子

We are running AWS Aurora(Serverless RDS) in our production environment. It has to scale between 2 capacity units(4GB RAM) and 8 capacity units(16GB RAM).

For the last 2 months, our database has never auto-scaled, it was running in the minimum capacity unit. In the past week, due to an increase in system usage, auto-scaling started triggering every few mins. It was scaling between 4 and 8 capacity units during the day time.

And since last week, we were getting an …

我有一个抽象类BaseTemplate和多个扩展它的类.在其中一个具体的class(SmsTemplate extends BaseTemplate)中,我们有一个私有变量Gson.我们Gson在抽象类中也有相同的私有变量().

在测试具体类的单元时,抽象类中的方法是从具体类调用的.在我的单元测试中,我Whitebox.setInternalState(smsTemplateObj, gsonObj);用来将Gson对象注入到私有成员中SmsTemplate,BaseTemplate但是Gson只是在子类中注入.在抽象类中,它的NULL意思是不注入.以下是实施.

请问有人可以告诉如何在抽象类中注入Gson对象吗？

abstract class BaseTemplate{

    private Gson gson;//Here its not getting injected

    protected String getContent(Content content){
        return gson.toJson(content); // ERROR - gson here throws NPE as its not injected
    }
}

class SmsTemplate extends BaseTemplate{

    private Gson gson;//Here its getting injected

    public String processTemplate(Content content){
        String strContent = getContent(content);
        ...
        ...
        gson.fromJson(strContent, Template.class);
    }
}

我们配置<time-to-live-seconds>为1200(20分钟)但缓存在缓存创建时间一分钟后自动逐出.

有人可以告诉如何在指定的时间段内使缓存生效吗？

我们在一个表中有超过2000万条记录，并且我们尝试更新3K记录，但是这花费了7分钟以上的时间，并且没有完成，因此终止了查询。

示例查询

UPDATE TABLE_A
SET STATUS = 'PENDING'
WHERE ID IN (
  SELECT ID
  FROM TMP_TABLE_A_STATUS_FIX
);   /*took more than 7 mins and didn't complete even after that*/

我们在临时表TMP_TABLE_A_STATUS_FIX（只有3K记录）中收集了所有需要更新的ID。

由于上述查询花费的时间太长，我们分别进行了如下更新：

UPDATE TABLE_A SET STATUS = 'PENDING' WHERE ID = 1;
UPDATE TABLE_A SET STATUS = 'PENDING' WHERE ID = 2;
UPDATE TABLE_A SET STATUS = 'PENDING' WHERE ID = 3;
.
.
.
UPDATE TABLE_A SET STATUS = 'PENDING' WHERE ID = 2999;
UPDATE TABLE_A SET STATUS = 'PENDING' WHERE …