for your first question, foo will not be cached since you only GET it. 

second, some client, such as libmemchaed, implements kick-retry mechanism. it 
will remove the dead node and retry it in every timeout interval. in addition, 
you may want to use replica to mimic a master-slave backup.

lastly, memocached stores in memory only. i extend the storage to disk for 
myself use, so we can cache much more items. recently added items will stores 
in memory and old ones moves to disk storage.

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----- Reply message -----
发件人: "Anurag Kapur" <[email protected]>
收件人: <[email protected]>
主题: memcahced cluster config. newbie question
日期: 周四, 9 月 20 日, 2012 年 9:36 下午
Hi,
I have just been reading the wiki to understand how memcached works. I have 
understood how to use it but have a question around the cluster configuration. 
Say key "foo" was stored on node A which has now gone down. A client requests 
for "foo", its not there on any node in the cluster and this is a cache miss. 
At this point would "foo" get cached again on a node that is still available in 
the cluster or will "foo" keep returning cache misses until node A comes back 
up?
Additionally, if the cluster indeed waits for node A to come back up, how is 
removal of nodes from a cluster configuration handled? 
I am keen to understand these internal workings of memcached so any pointers to 
existing documentation or an explanation would be much appreciated. Also, is 
there any documentation explaining how the hashing and key resolution work? How 
does the key resolution to map to a key to a specific memcached node? I think 
it happens in the client itself. Correct? 
Lastly, is memcached purely in-memory or can it write to disk as well?
Thanks in advance.
Anurag

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