App引擎停機時間

Question

Google的App引擎是否有過多停機時間，特別是關於數據存儲寫入？

另外，宕機時間似乎是在高流量時間期間安排的，例如，在下午中午與凌晨3:00。這是正常的嗎？隨着技術的成熟，它會不會改進？

Answer 1

簡短的回答

1. 下午VS清晨停機時間。數據存儲在下午比上午凌晨（太平洋時間;包括放置，更新和刪除可用性）更頻繁地被寫入不可用。

   注：我肯定會在非高峯時段進行谷歌像停機時間。因此，我希望他們會繼續儘量減少停機時間，或者儘可能在非高峯時段安排時間。

2. 停機趨勢。數據存儲不可用的15分鐘時間段數量一直在減少。在過去的366天中，每天平均有3.8個15分鐘的數據存儲空間。在過去的200天中，這一比例減少了60％，達到2.3天。過去幾個月的停機時間實際上相當不錯 - 自3月1日以來，每天停機時間不到0.25分鐘。這裏的數據存儲的圖形寫停機時間： Downtime trending http://imagebin.ca/img/4wkHVQPc.png

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答案

要回答你的問題的來源，我寫了this script從GAE's Datastore Status page提取停機數據。

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圖形

Datastore write downtime from 2009-Jul-20 to 2010-Jul-20 (4 hour bins)：

alt text http://imagebin.ca/img/p9ScWTm.png

Datastore write downtime from 2009-Jul-20 to 2010-Jul-20 (1 hour bins)：

alt text http://imagebin.ca/img/9FbLut2G.png

Datastore downtime from 2009-Jul-20 to 2010-Jul-20 (4 hour bins)：

alt text http://imagebin.ca/img/t3XKLk.png

Datastore downtime from 2010-Jan-01 to 2010-Jul-20 (4 hour bins)：

alt text http://imagebin.ca/img/k36T9h.png

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原始數據

（你可以在腳本的頂部調整的變量，如果你想收集你自己具有稍微不同參數的數據）：

# RAW Data: Each element counts the number of days in which the datastore 
# was unavailable for at least some portion of a given 15-minute window. The 
# first element corresponds to the time chunk from 00:00 to 00:15, and so on. 
RESULTS_SINCE_2010JAN01_BIN15 = [0, 0, 0, 0, 3, 11, 3, 3, 3, 3, 12, 3, 3, 3, 4, 14, 4, 4, 4, 4, 12, 2, 2, 2, 2, 14, 4, 4, 4, 4, 11, 2, 2, 2, 2, 11, 5, 5, 5, 5, 13, 4, 4, 4, 4, 14, 7, 5, 5, 5, 14, 4, 3, 3, 3, 13, 2, 2, 2, 2, 12, 5, 4, 4, 4, 14, 5, 3, 3, 3, 12, 7, 2, 2, 2, 5, 5, 0, 0, 0, 2, 9, 3, 2, 2, 2, 10, 1, 1, 1, 2, 9, 3, 3, 3, 15] 
RESULTS_SINCE_2009JUL20_BIN15 = [0, 0, 0, 0, 11, 21, 5, 5, 5, 5, 29, 6, 6, 6, 7, 38, 11, 11, 11, 11, 37, 7, 7, 7, 7, 44, 12, 12, 12, 12, 37, 10, 10, 10, 10, 34, 7, 7, 7, 7, 46, 11, 11, 11, 11, 39, 15, 13, 13, 13, 44, 13, 12, 12, 12, 44, 5, 5, 5, 5, 34, 11, 10, 10, 10, 40, 13, 11, 11, 11, 31, 21, 12, 12, 11, 19, 21, 4, 4, 4, 13, 28, 10, 9, 9, 16, 36, 10, 10, 10, 12, 32, 7, 7, 6, 35] 
RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN15 = [0, 0, 0, 0, 4, 12, 4, 4, 4, 4, 22, 6, 6, 6, 7, 27, 7, 7, 7, 7, 21, 6, 6, 6, 6, 32, 9, 9, 9, 9, 26, 8, 8, 8, 8, 27, 7, 7, 7, 7, 30, 7, 7, 7, 7, 27, 10, 8, 8, 8, 28, 10, 9, 9, 9, 28, 4, 4, 4, 4, 21, 4, 4, 4, 4, 25, 6, 4, 4, 4, 18, 14, 9, 10, 9, 16, 17, 2, 2, 2, 8, 18, 7, 6, 6, 9, 19, 5, 5, 5, 6, 18, 5, 5, 4, 21] 

# RESULTS DISTILLED FROM COLLECTED_RESULTS 
RESULTS_SINCE_2010JAN01_BIN60 = [RESULTS_SINCE_2010JAN01_BIN15[i*4]+RESULTS_SINCE_2010JAN01_BIN15[i*4+1]+RESULTS_SINCE_2010JAN01_BIN15[i*4+2]+RESULTS_SINCE_2010JAN01_BIN15[i*4+3] for i in xrange(24)] 
RESULTS_SINCE_2010JAN01_BIN240 = [RESULTS_SINCE_2010JAN01_BIN60[i*4]+RESULTS_SINCE_2010JAN01_BIN60[i*4+1]+RESULTS_SINCE_2010JAN01_BIN60[i*4+2]+RESULTS_SINCE_2010JAN01_BIN60[i*4+3] for i in xrange(6)] 
RESULTS_SINCE_2010JAN01_BIN480 = [RESULTS_SINCE_2010JAN01_BIN60[i*2]+RESULTS_SINCE_2010JAN01_BIN60[i*2+1] for i in xrange(3)] 
RESULTS_SINCE_2009JUL20_BIN60 = [RESULTS_SINCE_2009JUL20_BIN15[i*4]+RESULTS_SINCE_2009JUL20_BIN15[i*4+1]+RESULTS_SINCE_2009JUL20_BIN15[i*4+2]+RESULTS_SINCE_2009JUL20_BIN15[i*4+3] for i in xrange(24)] 
RESULTS_SINCE_2009JUL20_BIN240 = [RESULTS_SINCE_2009JUL20_BIN60[i*4]+RESULTS_SINCE_2009JUL20_BIN60[i*4+1]+RESULTS_SINCE_2009JUL20_BIN60[i*4+2]+RESULTS_SINCE_2009JUL20_BIN60[i*4+3] for i in xrange(6)] 
RESULTS_SINCE_2009JUL20_BIN480 = [RESULTS_SINCE_2009JUL20_BIN240[i*2]+RESULTS_SINCE_2009JUL20_BIN240[i*2+1] for i in xrange(3)] 
RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN60 = [RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN15[i*4]+RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN15[i*4+1]+RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN15[i*4+2]+RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN15[i*4+3] for i in xrange(24)] 
RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN240 = [RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN60[i*4]+RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN60[i*4+1]+RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN60[i*4+2]+RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN60[i*4+3] for i in xrange(6)] 
RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN480 = [RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN240[i*2]+RESULTS_WRITE_DOWNTIME_SINCE_2009JUL20_BIN240[i*2+1] for i in xrange(3)]