[libvirt] [test-API][PATCH] balloon_memory: add time break before dump xml
the xml dumped after setMemory is not accurate due to time delay, so take 10 sec sleep before dump to show the right xml info Signed-off-by: Wayne Sun <gsun@redhat.com> --- repos/domain/balloon_memory.py | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/repos/domain/balloon_memory.py b/repos/domain/balloon_memory.py index 7051a0a..5bf023a 100644 --- a/repos/domain/balloon_memory.py +++ b/repos/domain/balloon_memory.py @@ -209,6 +209,7 @@ def balloon_memory(params): logger.debug("dump the xml description of guest virtual machine %s" % domname) + time.sleep(10) dom_xml = domobj.XMLDesc(0) logger.debug("the xml definination is %s" % dom_xml) @@ -240,6 +241,7 @@ def balloon_memory(params): logger.debug("dump the xml description of \ guest virtual machine %s" % domname) + time.sleep(10) dom_xml = domobj.XMLDesc(0) logger.debug("the xml definination is %s" % dom_xml) -- 1.7.1
On 11/27/2012 03:02 PM, Wayne Sun wrote:
the xml dumped after setMemory is not accurate due to time delay, so take 10 sec sleep before dump to show the right xml info
Why it is necessary to sleep for a while, I don't think adding a sleep is a good way to solve problem. Please try to figure out the root cause. Guannan
On 11/27/2012 04:36 PM, Guannan Ren wrote:
On 11/27/2012 03:02 PM, Wayne Sun wrote:
the xml dumped after setMemory is not accurate due to time delay, so take 10 sec sleep before dump to show the right xml info
Why it is necessary to sleep for a while, I don't think adding a sleep is a good way to solve problem. Please try to figure out the root cause.
Guannan
DB recently change the code of get domain memory balloon value as in patch: http://www.redhat.com/archives/libvir-list/2012-May/msg00871.html If QEMU supports the BALLOON_EVENT QMP event, then we can avoid invoking 'query-balloon' when returning XML or the domain info. And in qemu patch: http://lists.gnu.org/archive/html/qemu-devel/2012-05/msg02833.html DB also emphasis in description: It is important to note that events are only discarded when they are obsoleted by a newer event. So an application is guarenteed to see the final balloon event, with at worst a 1 second delay. So when after do memory change, for dump domain xml to get balloon value, it will be controlled in 1 second delay. When i check with QMP with query-events commands on qemu-kvm-rhev-0.12.1.2-2.337.el6.x86_64: { "execute": "query-events"} {"error": {"class": "CommandNotFound", "desc": "The command query-events has not been found", "data": {"name": "query-events"}}} and this also in my log, so my qemu did not support this BALLOON_EVENT and using query-balloon to get current memory, and indeed 'query-balloon' is spotted in my log. This back to # vim src/qemu/qemu_driver.c +5330 /* Don't delay if someone's using the monitor, just use * existing most recent data instead */ so most recent data will be returned with query-balloon, that means if we query too fast, the result will not be accurate. I think add little time sleep is reasonable here for now, but after qemu support BALLOON_EVENT, then the sleep will be no use. So, what do you think? Wayne Sun 2012-11-27
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On 11/27/2012 07:01 PM, Wayne Sun wrote:
On 11/27/2012 04:36 PM, Guannan Ren wrote:
On 11/27/2012 03:02 PM, Wayne Sun wrote:
the xml dumped after setMemory is not accurate due to time delay, so take 10 sec sleep before dump to show the right xml info
Why it is necessary to sleep for a while, I don't think adding a sleep is a good way to solve problem. Please try to figure out the root cause.
Guannan
DB recently change the code of get domain memory balloon value as in patch: http://www.redhat.com/archives/libvir-list/2012-May/msg00871.html
If QEMU supports the BALLOON_EVENT QMP event, then we can avoid invoking 'query-balloon' when returning XML or the domain info.
And in qemu patch: http://lists.gnu.org/archive/html/qemu-devel/2012-05/msg02833.html
DB also emphasis in description:
It is important to note that events are only discarded when they are obsoleted by a newer event. So an application is guarenteed to see the final balloon event, with at worst a 1 second delay.
So when after do memory change, for dump domain xml to get balloon value, it will be controlled in 1 second delay.
When i check with QMP with query-events commands on qemu-kvm-rhev-0.12.1.2-2.337.el6.x86_64: { "execute": "query-events"} {"error": {"class": "CommandNotFound", "desc": "The command query-events has not been found", "data": {"name": "query-events"}}}
and this also in my log, so my qemu did not support this BALLOON_EVENT and using query-balloon to get current memory, and indeed 'query-balloon' is spotted in my log.
This back to # vim src/qemu/qemu_driver.c +5330
/* Don't delay if someone's using the monitor, just use * existing most recent data instead */
so most recent data will be returned with query-balloon, that means if we query too fast, the result will not be accurate.
I think add little time sleep is reasonable here for now, but after qemu support BALLOON_EVENT, then the sleep will be no use.
So, what do you think?
Okay, I got what you meant here, 10 seconds is too long, I plan to change it to 3 seconds as we discussed. Thanks for your patch. Guannan Ren
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Wayne Sun