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<div class="moz-cite-prefix">On 06/27/2014 07:15 PM, Wen Wang wrote:<br>
</div>
<blockquote cite="mid:53AD524B.6020909@linux.vnet.ibm.com"
type="cite">
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charset=ISO-8859-1">
Dear all,<br>
<b><br>
</b><b>Problems:</b><br>
Now our strategy for long time operation is using task which the
browser needs to check up-to-date task status time by time until
the task ends. It's time consuming and less efficient. Also there
exists several problems when locating each task when doing debug
generating and storage pool as well as some new features that
might use task strategy in the future. <br>
<br>
<b>Solution</b>:<br>
As talked with Sheldon and Zhengsheng, we came up with a solution
that avoid browser checking status every 200ms. Also, we might
need some more labels in each task to provide more information
when getting the task like we might need to indicate which
operation triggered certain task. What's in our mind is to use the
strategy that allow the server inform browser about the task
information. Our proposal is designed as follows.<br>
<br>
1) Browser needs to register to the back end to indicate which
part the result needs to reply to when the task finished.<br>
2) The back end use broker to manage message distribution: when a
task is finished or experiencing an error, back end inform the
browser certain part of work is finished or error.<br>
3) Using websocket of cherrypy to accomplish the message transfer.<br>
</blockquote>
Now let me elaborate above.<br>
<br>
For Browser, it can be an event loop worker.<br>
It can subscribe event message that users care to the back end
broker.<br>
listen the events from the broker and take some action for the
event.<br>
<br>
For back:<br>
The broker should collect and store the events from everywhere. <br>
The broker should dispatch the message to the client who subscribes
it. <br>
For some event, broker should determined whether it should dispatch
to user. <br>
Such a VM shutdown event, the broker just send it to the user who
has the access permission. (Yu Xing's suggestion)<br>
We had better define the event message format.<br>
<br>
We had better to find an existing python lib for it. If no we should
code it for ourself. <br>
[ client1
]
<br>
care VM | ^<br>
libvirt event -------------\ shutdown | | VM
shutdown<br>
\ V
| <br>
event 1 -------- -------------------------->[ broker ] <br>
/ ^
| dispatch<br>
event 2 ------------/ | |
<br>
subscribe | V
listen<br>
[ client2
]<br>
<br>
<br>
For websocket:<br>
There's also an issue about it.
<a class="moz-txt-link-freetext" href="https://github.com/kimchi-project/kimchi/issues/22">https://github.com/kimchi-project/kimchi/issues/22</a> <br>
The websocket is the pipe to connect the broker of the UI event
worker. <br>
We should support websocket proxying directly from the cherrypy
server on its given port. <br>
Zheng Sheng is working on it. It can work on cherrypy. Seems
something wrong with nginx. <br>
<br>
<br>
<br>
<blockquote cite="mid:53AD524B.6020909@linux.vnet.ibm.com"
type="cite"> <br>
Best Regards<br>
<br>
Wang Wen<br>
<br>
<br>
<br>
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</blockquote>
<br>
<br>
<pre class="moz-signature" cols="72">--
Thanks and best regards!
Sheldon Feng(冯少合)<a class="moz-txt-link-rfc2396E" href="mailto:shaohef@linux.vnet.ibm.com"><shaohef@linux.vnet.ibm.com></a>
IBM Linux Technology Center</pre>
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