Hi Wei,
On 06/01/2013 08:24 AM, Wei ZHOU wrote:
Wido,
Exactly. I have pushed the features into master.
If anyone object thems for technical reason till Monday, I will revert them.
For the sake of clarity I just want to mention again that we should
change the total IOps to R/W IOps asap so that we never release a
version with only total IOps.
You laid the groundwork for the I/O throttling and that's great! We
should however prevent that we create legacy from day #1.
Wido
-Wei
2013/5/31 Wido den Hollander <w...@widodh.nl>
On 05/31/2013 03:59 PM, John Burwell wrote:
Wido,
+1 -- this enhancement must to discretely support read and write IOPS. I
don't see how it could be fixed later because I don't see how we correctly
split total IOPS into read and write. Therefore, we would be stuck with a
total unless/until we decided to break backwards compatibility.
What Wei meant was merging it into master now so that it will go in the
4.2 branch and add Read / Write IOps before the 4.2 release so that 4.2
will be released with Read and Write instead of Total IOps.
This is to make the May 31st feature freeze date. But if the window moves
(see other threads) then it won't be necessary to do that.
Wido
I also completely agree that there is no association between network and
disk I/O.
Thanks,
-John
On May 31, 2013, at 9:51 AM, Wido den Hollander <w...@widodh.nl> wrote:
Hi Wei,
On 05/31/2013 03:13 PM, Wei ZHOU wrote:
Hi Wido,
Thanks. Good question.
I thought about at the beginning. Finally I decided to ignore the
difference of read and write mainly because the network throttling did
not
care the difference of sent and received bytes as well.
That reasoning seems odd. Networking and disk I/O completely different.
Disk I/O is much more expensive in most situations then network bandwith.
Implementing it will be some copy-paste work. It could be implemented in
few days. For the deadline of feature freeze, I will implement it after
that , if needed.
It think it's a feature we can't miss. But if it goes into the 4.2
window we have to make sure we don't release with only total IOps and fix
it in 4.3, that will confuse users.
Wido
-Wei
2013/5/31 Wido den Hollander <w...@widodh.nl>
Hi Wei,
On 05/30/2013 06:03 PM, Wei ZHOU wrote:
Hi,
I would like to merge disk_io_throttling branch into master.
If nobody object, I will merge into master in 48 hours.
The purpose is :
Virtual machines are running on the same storage device (local
storage or
share strage). Because of the rate limitation of device (such as
iops), if
one VM has large disk operation, it may affect the disk performance of
other VMs running on the same storage device.
It is neccesary to set the maximum rate and limit the disk I/O of VMs.
Looking at the code I see you make no difference between Read and
Write
IOps.
Qemu and libvirt support setting both a different rate for Read and
Write
IOps which could benefit a lot of users.
It's also strange, in the polling side you collect both the Read and
Write
IOps, but on the throttling side you only go for a global value.
Write IOps are usually much more expensive then Read IOps, so it seems
like a valid use-case where that an admin would set a lower value for
write
IOps vs Read IOps.
Since this only supports KVM at this point I think it would be of great
value to at least have the mechanism in place to support both,
implementing
this later would be a lot of work.
If a hypervisor doesn't support setting different values for read and
write you can always sum both up and set that as the total limit.
Can you explain why you implemented it this way?
Wido
The feature includes:
(1) set the maximum rate of VMs (in disk_offering, and global
configuration)
(2) change the maximum rate of VMs
(3) limit the disk rate (total bps and iops)
JIRA ticket: https://issues.apache.org/****
jira/browse/CLOUDSTACK-1192<https://issues.apache.org/**jira/browse/CLOUDSTACK-1192>
<ht**tps://issues.apache.org/jira/**browse/CLOUDSTACK-1192<https://issues.apache.org/jira/browse/CLOUDSTACK-1192>
FS (I will update later) :
https://cwiki.apache.org/****confluence/display/CLOUDSTACK/****<https://cwiki.apache.org/**confluence/display/CLOUDSTACK/**>
VM+Disk+IO+Throttling<https://**cwiki.apache.org/confluence/**
display/CLOUDSTACK/VM+Disk+IO+**Throttling<https://cwiki.apache.org/confluence/display/CLOUDSTACK/VM+Disk+IO+Throttling>
Merge check list :-
* Did you check the branch's RAT execution success?
Yes
* Are there new dependencies introduced?
No
* What automated testing (unit and integration) is included in the new
feature?
Unit tests are added.
* What testing has been done to check for potential regressions?
(1) set the bytes rate and IOPS rate on CloudStack UI.
(2) VM operations, including
deploy, stop, start, reboot, destroy, expunge. migrate, restore
(3) Volume operations, including
Attach, Detach
To review the code, you can try
git diff c30057635d04a2396f84c588127d7e****be42e503a7
f2e5591b710d04cc86815044f5823e****73a4a58944
Best regards,
Wei
[1]
https://cwiki.apache.org/****confluence/display/CLOUDSTACK/****<https://cwiki.apache.org/**confluence/display/CLOUDSTACK/**>
VM+Disk+IO+Throttling<https://**cwiki.apache.org/confluence/**
display/CLOUDSTACK/VM+Disk+IO+**Throttling<https://cwiki.apache.org/confluence/display/CLOUDSTACK/VM+Disk+IO+Throttling>
[2] refs/heads/disk_io_throttling
[3]
https://issues.apache.org/****jira/browse/CLOUDSTACK-1301<https://issues.apache.org/**jira/browse/CLOUDSTACK-1301>
<ht**tps://issues.apache.org/jira/**browse/CLOUDSTACK-1301<https://issues.apache.org/jira/browse/CLOUDSTACK-1301>
<ht**tps://issues.apache.org/**jira/**browse/CLOUDSTACK-2071<http://issues.apache.org/jira/**browse/CLOUDSTACK-2071>
<**https://issues.apache.org/**jira/browse/CLOUDSTACK-2071<https://issues.apache.org/jira/browse/CLOUDSTACK-2071>
(**CLOUDSTACK-1301
- VM Disk I/O Throttling)
