Re: [dpdk-dev] [PATCH 3/6] vhost: add reconnect ability

["Xie, Huawei" <huawei.xie@intel.com>]

On 5/10/2016 2:08 AM, Yuanhan Liu wrote:
> On Mon, May 09, 2016 at 04:47:02PM +0000, Xie, Huawei wrote:
>> On 5/7/2016 2:36 PM, Yuanhan Liu wrote:
>>> +static void *
>>> +vhost_user_client_reconnect(void *arg)
>>> +{
>>> +	struct reconnect_info *reconn = arg;
>>> +	int ret;
>>> +
>>> +	RTE_LOG(ERR, VHOST_CONFIG, "reconnecting...\n");
>>> +	while (1) {
>>> +		ret = connect(reconn->fd, (struct sockaddr *)&reconn->un,
>>> +				sizeof(reconn->un));
>>> +		if (ret == 0)
>>> +			break;
>>> +		sleep(1);
>>> +	}
>>> +
>>> +	vhost_user_add_connection(reconn->fd, reconn->vsocket);
>>> +	free(reconn);
>>> +
>>> +	return NULL;
>>> +}
>>> +
>> We could create hundreds of vhost-user ports in OVS. Wihout connections
>> with QEMU established, those ports are just inactive. This works fine in
>> server mode.
>> With client modes, do we need to create hundreds of vhost threads? This
>> would be too interruptible.
>> How about we create only one thread and do the reconnections for all the
>> unconnected socket?
> Yes, good point and good suggestion. Will do it in v2.

Hi Michael:
This reminds me another irrelevant issue.
In OVS, currently for each vhost port, we create an unix domain socket,
and QEMU vhost proxy connects to this socket, and we use this to
identify the connection. This works fine but is our workaround,
otherwise we have no way to identify the connection.
Do you think if this is an issue?
Do we have plan to support identification in VHOST_USER_MESSAGE? With
the identification, if vhost as server, we only need to create one
socket which receives multiple connections, and use the ID in the
message to identify the connection.

/huawei


>
> Thanks.
>
> 	--yliu
>