[Libvir] Network blocking issue

[Richard W.M. Jones]

Daniel P. Berrange wrote:
> On Mon, Sep 17, 2007 at 03:49:37PM +0100, Richard W.M. Jones wrote:
>> Daniel Veillard wrote:
>>>  Is there a configuration knob in the RPC layer to lower the
>>> timeout delay ? Some calls are slow, but we should not reach a 2mn
>>> timeout, that's very very long I think.
>> Migrations might take some time.
>>
>> In any case the RPC code just does 'sendto' followed by 'recvfrom'. 
>> There is no timeout to adjust on the client side.
>>
>> Shuveb's problem is that TCP doesn't gracefully handle the case where 
>> the ethernet cable is pulled out.  There may be a socket option which 
>> helps for this.
> 
> That depends on your definition of graceful.
> 
> Shuveb's definition is that he wants the connection to fail & give an error
> back to the app.
> 
> My definition is that TCP should keep retrying until I plug the cable back
> in, so I don't get unneccessary failures if i'm just switching cables
> around. Likewise if there's temporary outages anywhere else in the link
> between the client & server.

Yes actually I agree with you on that one.  On the other hand there is 
no way for Shuveb to set TCP socket options on the socket other than 
making a private copy of the libvirt code and hacking it.  So a patch to 
add yet another query string flag to the remote URI or to expose the 
remote socket somehow might be acceptable.

Rich.

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