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Posted to dev@mina.apache.org by "jpalacios (JIRA)" <ji...@apache.org> on 2018/10/24 03:05:00 UTC
[jira] [Created] (DIRMINA-1096) Massive object graph in
NioSocketSession
jpalacios created DIRMINA-1096:
----------------------------------
Summary: Massive object graph in NioSocketSession
Key: DIRMINA-1096
URL: https://issues.apache.org/jira/browse/DIRMINA-1096
Project: MINA
Issue Type: Bug
Affects Versions: 2.0.16
Reporter: jpalacios
I'm looking at a heap dump from one of our customers where the retained heap size for some {{NioSocketSession}} instances is almost 1GB.
From the looks of the dump MINA has created a massive object graph where:
{code}
NioSocketSession -> SelectionKeyImpl -> EpollSelectorImpl -> HashMap -> SelectionKeyImpl -> NioSocketSession -> ...
{code}
From the looks of the obeject IDs these are not loops
Each individual object is not large by itself but at the top of the graph the accumulated retained size is enough to produce an OOME
Could you help me understand how MINA can produce such a massive object graph? Should MINA apply any defense mechanism to prevent this??
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Re: [jira] [Created] (DIRMINA-1096) Massive object graph in NioSocketSession
Posted by Jonathan Valliere <jo...@apache.org>.
Sounds like the master SelectorKey HashMap owned by the Selector. This is
part of the Java NIO API, not MINA.
https://docs.oracle.com/javase/7/docs/api/java/nio/channels/Selector.html
You can call selector.keys() which is actually that HashMap you are
referring to. I think there is a total of 3 HashMaps used by the Selector
which contain SelectionKeyImpl objects.
On Tue, Oct 23, 2018 at 11:05 PM jpalacios (JIRA) <ji...@apache.org> wrote:
> jpalacios created DIRMINA-1096:
> ----------------------------------
>
> Summary: Massive object graph in NioSocketSession
> Key: DIRMINA-1096
> URL: https://issues.apache.org/jira/browse/DIRMINA-1096
> Project: MINA
> Issue Type: Bug
> Affects Versions: 2.0.16
> Reporter: jpalacios
>
>
> I'm looking at a heap dump from one of our customers where the retained
> heap size for some {{NioSocketSession}} instances is almost 1GB.
>
> From the looks of the dump MINA has created a massive object graph where:
> {code}
> NioSocketSession -> SelectionKeyImpl -> EpollSelectorImpl -> HashMap ->
> SelectionKeyImpl -> NioSocketSession -> ...
> {code}
>
> From the looks of the obeject IDs these are not loops
> Each individual object is not large by itself but at the top of the graph
> the accumulated retained size is enough to produce an OOME
>
> Could you help me understand how MINA can produce such a massive object
> graph? Should MINA apply any defense mechanism to prevent this??
>
>
>
> --
> This message was sent by Atlassian JIRA
> (v7.6.3#76005)
>