MySQL Bugs: #64566: NDB Memcache Freelist Depletion

Bug #64566	NDB Memcache Freelist Depletion
Submitted:	6 Mar 2012 16:04	Modified:	9 Jan 2015 10:17
Reporter:	John Duncan	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Cluster: Cluster (NDB) storage engine	Severity:	S2 (Serious)
Version:	7.2.4	OS:	Any
Assigned to:		CPU Architecture:	Any
Tags:	Memcache

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Description:
In 7.2.4, with some memcache error conditions (such as "key too large"), the Ndb object that was obtained for the operation is not put back onto the free list.  If enough of these errors accumulate, the free list will empty, and further memcache operations in that thread will result in "temporary" errors (No Ndb available).   At this point memcached server needs to be restarted.

How to repeat:
This condition can sometimes be triggered using "memslap".