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Bug 1497197 - Calling virDomain.getMemoryStats and virDomain.diskErrors may block the entire process [rhel-7.4.z]
Summary: Calling virDomain.getMemoryStats and virDomain.diskErrors may block the entir...
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: libvirt-python
Version: 7.4
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: rc
: ---
Assignee: Pavel Hrdina
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On: 1496517
Blocks: 1481022
TreeView+ depends on / blocked
 
Reported: 2017-09-29 12:54 UTC by Oneata Mircea Teodor
Modified: 2025-08-21 05:39 UTC (History)
17 users (show)

Fixed In Version: libvirt-python-3.2.0-3.el7_4.1
Doc Type: Bug Fix
Doc Text:
When the storage of a guest hosted on a Red Hat Virtualization Hypervisor system became inaccessible, the host in some cases became unresponsive. This update fixes the behavior of the virDomainMemoryStats() function, which prevents the described problem from occurring.
Clone Of: 1496517
Environment:
Last Closed: 2017-10-19 15:16:16 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)
test scripts (1.10 KB, text/plain)
2017-10-10 01:44 UTC, weizhang 		no flags Details
test xml (3.44 KB, text/plain)
2017-10-10 01:46 UTC, weizhang 		no flags Details
View All


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2017:2948 0 normal SHIPPED_LIVE libvirt-python bug fix update 2017-10-19 18:51:22 UTC

Description Oneata Mircea Teodor 2017-09-29 12:54:40 UTC 
This bug has been copied from bug #1496517 and has been proposed to be backported to 7.4 z-stream (EUS).
Comment 5 weizhang 2017-10-10 01:41:22 UTC 
Verified on libvirt-python-3.2.0-3.el7_4.1

Reproduce steps on libvirt-python-3.2.0-3.el7:
1. prepare nfs with iso in it and add this cdrom in guest xml
2. restart libvirtd 
3. on console 1, run
# python ./test.py
We can see the output for main thread and other 2 threads, and the vm started

run abount 30-40s, on console 2 run
# iptables -A OUTPUT -d [NFS_SERVER] -j DROP
to block the nfs access

For several min, the qemu process into Dl state, and the output for print will hang for 30s, see the time I marked in the log

*******
print time: 2017-10-09 19:44:06.384147

print time: 2017-10-09 19:44:07.385305

print time: 2017-10-09 19:44:08.386450

start memoryStats: 2017-10-09 19:44:08.395628 <------------- here the time

libvirt: QEMU Driver error : Timed out during operation: cannot acquire state change lock (held by remoteDispatchConnectGetAllDomainStats)
print time: 2017-10-09 19:44:38.395709 
Exception in thread Thread-2:
Traceback (most recent call last):
  File "/usr/lib64/python2.7/threading.py", line 812, in __bootstrap_inner
    self.run()
  File "/usr/lib64/python2.7/threading.py", line 765, in run
    self.__target(*self.__args, **self.__kwargs)
  File "./test.py", line 19, in memory_stats
    dom.memoryStats()
  File "/usr/lib64/python2.7/site-packages/libvirt.py", line 1450, in memoryStats
    if ret is None: raise libvirtError ('virDomainMemoryStats() failed', dom=self)
libvirtError: Timed out during operation: cannot acquire state change lock (held by remoteDispatchConnectGetAllDomainStats)

print time: 2017-10-09 19:44:39.396900  <-------------- here the time

print time: 2017-10-09 19:44:40.398037

print time: 2017-10-09 19:44:41.399191
**********

On libvirt-python-3.2.0-3.el7_4.1 the print will finished without hang, so verify it. 

The test xml and scripts will be given on attachment
Comment 6 weizhang 2017-10-10 01:44:58 UTC 
Created attachment 1336584 [details]
test scripts
Comment 7 weizhang 2017-10-10 01:46:08 UTC 
Created attachment 1336585 [details]
test xml
Comment 9 errata-xmlrpc 2017-10-19 15:16:16 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2017:2948
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