franz1981 edited a comment on issue #2832: ARTEMIS-2482 Large messages could 
leak native ByteBuffers
   @wy96f I've taken a second look to the way Netty handle thread local 
`ByteBuf`pools and I can confirm that 
`-Dio.netty.allocator.useCacheForAllThreads=false` should save non-netty 
threads from creating such thread local regions for tiny/small/medium sized 
   While related to 
   > but they just contain wrappers to direct memory that cannot be released 
(is part of the pool and they have no cleaner). The impact should be way less 
then IOUtil that pool native ByteBuffers holding exclusively native memory that 
won't be reused anymore...
   I have to add more detail and I was wrong: the tiny/small/medium thread 
local caches are actually leaking memory regions (with default 
`io.netty.allocator.useCacheForAllThread`) that need the holding thread to die 
in order to make them available to other threads again, but their size is quite 
small by default and the size I've chosen as `LARGE_MESSAGE_CHUNK_SIZE` (ie 100 
* 1024) is `medium` but doesn't fall in any of those caches, so no real leak 
will happen until we allocate something smaller (could happen but is rare).
   IMO we should consider 2 separate improvements for a separate PR:
   - allow threads to stay alive forever and in a fixed number, but just idle 
(and maybe using the FJ thread pool executor instead of the AMQ thread pool 
executor in that case): in that case we can consider such caches to be ok to be 
used by *all* threads (including non-netty ones), because the leak is just to 
cope with future load
   - for the AMQ thread pool executor as it is, make the presence of such 
caches configurable and off by default
   Thanks for the comment, good catch!

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