libvirt users - Dec 2013 - Using Java bindings to event callback

Hi

My test environment :

CentOS 6.3 6.4
Ubuntu 13.10

For CentOS 6.4

libvirt-java-0.4.9-1.el6.noarch
libvirt-python-0.10.2-29.el6.x86_64
libvirt-client-0.10.2-29.el6.x86_64
libvirt-0.10.2-29.el6.x86_64

I am try to use java bindings to event callback.

int register = conn.domainEventRegisterAny(null, 0, cb);

But always get the following error message:

libvirt: Remote Driver error : adding cb to list
exception caught:org.libvirt.LibvirtException: adding cb to list
level:VIR_ERR_ERROR
code:VIR_ERR_RPC
domain:VIR_FROM_REMOTE
hasConn:false
hasDom:false
hasNet:false
message:adding cb to list
str1:%s
str2:adding cb to list
str3:null
int1:-1
int2:-1

By the way I also trace the mail list

*[libvirt] [PATCH] Java bindings for domain events* (2008 Nov 07)
*[libvirt] [PATCH 1/2] Java bindings for domain events**[libvirt]
[PATCH 2/2] Java bindings for domain events* (2008 Nov 18) --> Reject
patch*Re: [libvirt] [PATCH 1/2] Java bindings for domain events* (2008
Dec)  —>No Result*[libvirt-users] Using Java bindings to event
callback * (2010 Jul) —>No Result
*[libvirt] [PATCH 0/2] Libvirt-java event handling (2011Jul)* —>
I think most drivers don't support that. We have a custom driver for
our hypervisor and it works.

*[libvirt] [libvirt-java] [PATCH 00/12] event support* (2013 Jan)
—> *Re: [libvirt] [libvirt-java] [PATCH 00/12] event support (2013
Mar)*  --> No Result
Any suggestions?


Thanks,

Howie

At Thu, 5 Dec 2013 16:26:36 +0800,
Howie wrote:
> 
> Hi
> 
> My test environment :
> 
> CentOS 6.3 6.4
> Ubuntu 13.10
> 
> For CentOS 6.4
> 
> libvirt-java-0.4.9-1.el6.noarch
> libvirt-python-0.10.2-29.el6.x86_64
> libvirt-client-0.10.2-29.el6.x86_64
> libvirt-0.10.2-29.el6.x86_64
> 
> I am try to use java bindings to event callback.
> 
> int register = conn.domainEventRegisterAny(null, 0, cb);
> 
> But always get the following error message:
> 
> libvirt: Remote Driver error : adding cb to list
> exception caught:org.libvirt.LibvirtException: adding cb to list
> level:VIR_ERR_ERROR
> code:VIR_ERR_RPC
> domain:VIR_FROM_REMOTE
> hasConn:false
> hasDom:false
> hasNet:false
> message:adding cb to list
> str1:%s
> str2:adding cb to list
> str3:null
> int1:-1
> int2:-1
At first, you need to initialize an event loop - before connecting to
the libvirt daemon.

Then you need to run that event loop in order to process the events.

If you're using an official libvirt-java release your out of luck as
this is not really supported.
> By the way I also trace the mail list
> 
> *[libvirt] [PATCH] Java bindings for domain events* (2008 Nov 07)
> *[libvirt] [PATCH 1/2] Java bindings for domain events**[libvirt]
> [PATCH 2/2] Java bindings for domain events* (2008 Nov 18) --> Reject
> patch*Re: [libvirt] [PATCH 1/2] Java bindings for domain events* (2008
> Dec)  —>No Result*[libvirt-users] Using Java bindings to event
> callback * (2010 Jul) —>No Result
> *[libvirt] [PATCH 0/2] Libvirt-java event handling (2011Jul)* —>
> I think most drivers don't support that. We have a custom driver for
> our hypervisor and it works.
> 
> *[libvirt] [libvirt-java] [PATCH 00/12] event support* (2013 Jan)
> —> *Re: [libvirt] [libvirt-java] [PATCH 00/12] event support (2013
> Mar)*  --> No Result
> Any suggestions?
I'm the author of the latter patches. I haven't had the time working
on these and didn't receive solid reviews on the development list.

A month ago, I began working on them again and have changed large
parts of the interface to simplify it and add more features. Currently
I'm testing the implementation - looks good so far; a small test
program is now running since 9 days straight.

Here's a small sample code to wet your appetite:

----
import org.libvirt.*
import org.libvirt.event.*;

class Monitor implements RebootListener, LifecycleListener {
  @Override
  public void onReboot(Domain d) {
    ...
  }

  @Override
  public int onLifecycleChange(Domain d, DomainEvent event) {
    ...
    return 0;
  }
}

// required!
Connect.initEventLoop();

Connect c = new Connect("qemu:///system");
Monitor m = new Monitor();

c.addRebootListener(m);
c.addLifecycleListener(m);

// run event loop
c.setKeepAlive(5, 3);
while (c.isAlive) c.processEvent();
----

I hope to get this upstream someday, but momentarily I'm not totally
satisfied and would like to think about it once more.

Anyway, comments are very welcome!

Claudio
-- 
AV-Test GmbH, Henricistraße 20, 04155 Leipzig, Germany
Phone: +49 341 265 310 19
Web:<http://www.av-test.org>

Eingetragen am / Registered at: Amtsgericht Stendal (HRB 114076)
Geschaeftsfuehrer (CEO): Andreas Marx, Guido Habicht, Maik Morgenstern