AppEngine前端到数据库延迟暂时〜10秒每个〜20个调用？

这个（见下图）自3/7发生。当然，这可能是因为实例的加载和卸载。但是你知道GAE的其他原因是这样吗？AppEngine前端到数据库延迟暂时〜10秒每个〜20个调用？

这不是一个很高的复制实例。在测试期间，我们只有我们的测试客户端调用运行了多达5个F2实例。基本上有数据库调用，图像处理和memcache使用。

已经有2个问题，看起来等于： http://code.google.com/p/googleappengine/issues/detail?id=4180&sort=priority&colspec=ID%20Type%20Component%20Status%20Stars%20Summary%20Language%20Priority%20Owner%20Log

http://code.google.com/p/googleappengine/issues/detail?id=6309&sort=priority&colspec=ID%20Type%20Component%20Status%20Stars%20Summary%20Language%20Priority%20Owner%20Log

还有的在论坛中的条目： https://groups.google.com/forum/#!topic/google-appengine/js5CeRWLQZ0/discussion

GAE-J Appstat Chart

记录（吉文要求）表明，持久性管理器似乎需要6秒来初始化：

2012-03-11 15:32:47.543 /api/yyy 200 16811ms 0kb xxx/1.1 CFNetwork/548.1.4 Darwin/11.0.0 
78.53.230.114 - - [11/Mar/2012:07:32:47 -0700] "POST /api/yyy HTTP/1.1" 200 94 - "zzz/1.1 CFNetwork/548.1.4 Darwin/11.0.0" "zzz.appspot.com" ms=16812 cpu_ms=6040 api_cpu_ms=82 cpm_usd=0.167820 pending_ms=5765 instance=00c71b117ca3858c47bdc41d5b30a732dd76eaaf 
I 2012-03-11 15:32:37.196 
www.server.xxxServlet getvvv: 1 
I 2012-03-11 15:32:37.202 
www.server.xxxServlet getvvv: hash 
I 2012-03-11 15:32:37.207 
www.server.xxxServlet getvvv: get PM (PersistenceManager pm = PMF.get().getPersistenceManager();) 
I 2012-03-11 15:32:43.606 
www.server.xxxServlet getvvv: get data 
I 2012-03-11 15:32:47.355 
www.server.xxxServlet getvvv: got data 
I 2012-03-11 15:32:47.388 
www.server.xxxServlet getvvv: done

和PMF被实现为：

public final class PMF { 
    private static final PersistenceManagerFactory pmfInstance = 
     JDOHelper.getPersistenceManagerFactory("transactions-optional"); 

    private PMF() {} 

    public static PersistenceManagerFactory get() { 
     return pmfInstance; 
    } 
}

来源

2012-03-09 ollie