Description of problem:
During the HA tests hosts was marked as NonResponsive because of timeouts.

Version-Release number of selected component (if applicable):
I'm opening bug against vdsm but I'm in doubt if it's vdsm's fault to be honest
rhevm-backend-3.5.4.2-1.3.el6ev.noarch
vdsm-4.16.26-1.el6ev.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Install 8 hypervisors and add them to manager. Each HV has 1-2 VMs running (it doesn't matter if PM is configured or not)
2. Block network communication on 4 HVs


Actual results:
All hypervisors are marked as nonResponsive including healthy ones

Expected results:
Only 4 problematic hypervisors should be marked as NonResponsive and fenced out (if configured)

Additional info:

engine.log contains many TimeoutExceptions which are normal because of half of the hosts don't have network connectivity. But this one are not normal:

2015-10-10 04:43:36,952 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.ListVDSCommand] (DefaultQuartzScheduler_Worker-44) Command ListVDSCommand(HostName = rhev4, HostId = efd6bcec-37b1-41a9-9152-be5ce956ae0c, vds=Host[rhev4,efd6bcec-37b1-41a9-9152-be5ce956ae0c]) execution failed. Exception: VDSNetworkException: VDSGenericException: VDSNetworkException: Message timeout which can be caused by communication issues <== There are not corresponding records in vdsm.log 

2015-10-10 04:43:44,737 INFO  [org.ovirt.vdsm.jsonrpc.client.reactors.ReactorClient] (SSL Stomp Reactor) Connecting to /10.65.161.73 <== IP address of rhev4 host and this connection attempt was logged (see below)
[....]

2015-10-10 04:46:50,987 INFO  [org.ovirt.engine.core.vdsbroker.vdsbroker.GetCapabilitiesVDSCommand] (DefaultQuartzScheduler_Worker-24) HostName = rhev4
2015-10-10 04:46:50,987 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.GetCapabilitiesVDSCommand] (DefaultQuartzScheduler_Worker-24) Command GetCapabilitiesVDSCommand(HostName = rhev4, HostId = efd6bcec-37b1-41a9-9152-be5ce956ae0c, vds=Host[rhev4,efd6bcec-37b1-41a9-9152-be5ce956ae0c]) execution failed. Exception: VDSNetworkException: VDSGenericException: VDSNetworkException: Message timeout which can be caused by communication issues


vdsm log:

Detector thread::DEBUG::2015-10-10 04:43:44,731::protocoldetector::187::vds.MultiProtocolAcceptor::(_add_connection) Adding connection from 10.65.161.80:46605 <== Connection added but stomp command was not parsed
Thread-27::DEBUG::2015-10-10 04:43:45,883::fileSD::262::Storage.Misc.excCmd::(getReadDelay) /bin/dd if=/rhev/data-center/mnt/10.65.161.80:_domain_iso/9e2e5b05-22fc-422a-bf17-37534e38f9bc/dom_md/metadata iflag=direct of=/dev/null bs=4096 count=1 (cwd None)
Thread-27::DEBUG::2015-10-10 04:43:45,891::fileSD::262::Storage.Misc.excCmd::(getReadDelay) SUCCESS: <err> = '0+1 records in\n0+1 records out\n328 bytes (328 B) copied, 0.000199751 s, 1.6 MB/s\n'; <rc> = 0
Thread-864::DEBUG::2015-10-10 04:43:46,364::libvirtconnection::143::root::(wrapper) Unknown libvirterror: ecode: 80 edom: 20 level: 2 message: metadata not found: Requested metadata element is not present
Thread-890::DEBUG::2015-10-10 04:43:46,471::libvirtconnection::143::root::(wrapper) Unknown libvirterror: ecode: 80 edom: 20 level: 2 message: metadata not found: Requested metadata element is not present
Thread-22::DEBUG::2015-10-10 04:43:51,667::blockSD::596::Storage.Misc.excCmd::(getReadDelay) /bin/dd if=/dev/a4ef59c4-a97a-498d-84a0-a294fdc83c50/metadata iflag=direct of=/dev/null bs=4096 count=1 (cwd None)
Thread-22::DEBUG::2015-10-10 04:43:51,676::blockSD::596::Storage.Misc.excCmd::(getReadDelay) SUCCESS: <err> = '1+0 records in\n1+0 records out\n4096 bytes (4.1 kB) copied, 0.000221506 s, 18.5 MB/s\n'; <rc> = 0

[.. repeated...] 

Detector thread::DEBUG::2015-10-10 04:44:14,892::protocoldetector::201::vds.MultiProtocolAcceptor::(_remove_connection) Connection removed from 10.65.161.80:46605