cloudstack-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF subversion and git services (JIRA)" <>
Subject [jira] [Commented] (CLOUDSTACK-9348) CloudStack Server degrades when a lot of connections on port 8250
Date Wed, 04 May 2016 14:32:12 GMT


ASF subversion and git services commented on CLOUDSTACK-9348:

Commit 0154da6417ab1dc0fa9719df4543e72ca5f2c178 in cloudstack's branch refs/heads/master from
[;h=0154da6 ]

CLOUDSTACK-9348: Unit test to demonstrate denial of service attack

The NioConnection uses blocking handlers for various events such as connect,
accept, read, write. In case a client connects NioServer (used by
agent mgr to service agents on port 8250) but fails to participate in SSL
handshake or just sits idle, this would block the main IO/selector loop in
NioConnection. Such a client could be either malicious or aggresive.

This unit test demonstrates such a malicious client that can perform a
denial-of-service attack on NioServer that blocks it to serve any other client.

Signed-off-by: Rohit Yadav <>

> CloudStack Server degrades when a lot of connections on port 8250
> -----------------------------------------------------------------
>                 Key: CLOUDSTACK-9348
>                 URL:
>             Project: CloudStack
>          Issue Type: Bug
>      Security Level: Public(Anyone can view this level - this is the default.) 
>            Reporter: Rohit Yadav
>            Assignee: Rohit Yadav
>             Fix For: 4.9.0
> An intermittent issue was found with a large CloudStack deployment, where servers could
not keep agents connected on port 8250.
> All connections are handled by accept() in NioConnection:
> A new connection is handled by accept() which does blocking SSL handshake. A good fix
would be to make this non-blocking and handle expensive tasks in separate threads/pool. This
way the main IO loop won't be blocked and can continue to serve other agents/clients.

This message was sent by Atlassian JIRA

View raw message