java memcached client

André Cruz andre.cruz at
Fri Dec 21 11:35:03 UTC 2007

Hello all.

I've been using the java memcached API (v1.6[.1]) ( 
) for some months now. Lately I've been seeing a strange problem.

Some adds fail (return false) but when I try to get the key I was  
trying to add, the key is there and with the correct value. And no,  
the key was not there before the add.
Here are some logs:

2007-12-19 23:47:22,623 [TP-Processor45] DEBUG - Preparing to store session email = XXX at 
  date = Wed Dec 19 23:47:22 WET 2007
2007-12-19 23:47:22,623 [TP-Processor45] INFO   
com.danga.MemCached.MemCachedClient - ++++ serializing for key:  
sapo_sso_session%3A1ca2fabf-dd55-4a2d-93d3-90bc7f44368b for class:
2007-12-19 23:47:22,623 [TP-Processor45] INFO   
com.danga.MemCached.MemCachedClient - ++++ memcache cmd (result code):  
add sapo_sso_session%3A1ca2fabf-dd55-4a2d-93d3-90bc7f44368b 8  
1198111642 165
2007-12-19 23:47:22,623 [TP-Processor45] ERROR  
com.danga.MemCached.MemCachedClient - ++++ error storing data in cache  
for key: sapo_sso_session%3A1ca2fabf-dd55-4a2d-93d3-90bc7f44368b --  
length: 165
2007-12-19 23:47:22,623 [TP-Processor45] ERROR  
com.danga.MemCached.MemCachedClient - NOT_FOUND
2007-12-19 23:47:22,624 [TP-Processor45] ERROR - Add returned false for key  

It seems the add is returning NOT_FOUND?! This return value is not in  
the memcached API documentation so it seems strange. I have 8 memcache  
servers configured, maybe some concurrency problems between the  
threads and this is the result to another command?

I've tried to contact Greg Whalin but got no answer. Has anyone seen  
this problem before?

The memcache server version is 1.1.12, a bit old, but I checked the  
changelog and didn't find anything related to a bug of this kind so it  
seems it's in the java API I'm using.

Best regards,
André Cruz

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