cloudstack-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Nitin Mehta <>
Subject Re: Object_Store storage refactor Meeting Notes
Date Fri, 14 Jun 2013 08:16:37 GMT

On 13/06/13 10:08 PM, "John Burwell" <> wrote:

>Edison Su, Min Chen, Animesh Chaturvedi, and myself met via
>teleconference on 11 June 2013 @ 1:30 PM EDT.  The goal of the meeting
>was determine the path forward for merging the object_store branch by the
>4.2 freeze date, 30 June 2013.  The conversation focused on the following
>	* Staging area mechanism
>	* Removing dependencies from the Storage to the Hypervisor layer
>	* Dependencies of other patches on object_store
>	* QA's desire to start testing the patch ASAP
>Min, Edison, and I agreed that the staging mechanism must age out files
>and use a reference count to ensure that file in-use are not prematurely
>purged.  While we agree that some form of reservation system is required,
>Edison is concerned that it will be too conservative and create

Can you please elaborate on the fact that it is too conservative - we just
can't purge the files when they are still in use correct ? We can use a
combination of LRU + reference count, trying to purge the LRU files if
their reference count <= 0 as a start ?

>As we delved deeper into the subject of the storage to hypervisor
>dependencies and the reservation mechanism, we determined that NFS
>storage would still need to be the size of the secondary storage data
>set.  Since the hypervisor layer has not been completely fitted to the
>new storage layer, NFS would be still required for a number of
>operations.  Based on this realization, we decided to de-scope the
>staging mechanism, and leave the 4.2 object store functionality the same
>as 4.1.  Therefore, NFS will remain the secondary storage of record, and
>object storage will serve as backup/multi-zone sync.

I am not sure how we can comment its going to be the same as 4.1 - is it
from the end user perspective ? The internal semantics and their flow have
changed. This needs to be elaborated and properly documented. Also I am
not sure if the feature is supported on the upgrade path or is it ? Need
more documentation here.

>In 4.3, we will fit the hypervisor layer for the new storage layer which
>will allow object stores to server as secondary storage.  This work will
>include removing the storage to hypervisor dependencies.  For 4.2, Edison
>and Min have implemented the critical foundation necessary to establish
>our next generation storage layer.  There simply was not enough time in
>this development cycle to make these changes and fit the hypervisor layer.
>Due to the size of the patch, Animesh voiced QA's concerned regarding
>test scope and impact.  As such, we want to get the merge completed as
>soon as possible to allow testing to begin.  We discussed breaking up the
>patch, but we could not devise a reasonable set of chunks there were both
>isolated and significantly testable.  Therefore, the patch can only be
>delivered in its current state.  We also walked through potential
>dependencies between the storage framework changes and the solidfire
>branch.  It was determined that these two merges could occur
>Finally, Animesh is going to setup a meeting at Citrix's Santa Clara
>office on 26 June 2013 (the day after Collab ends) to discuss the path
>forward for 4.3 and work through a high-level design/approach to fitting
>the hypervisor layer to exploit the new storage capabilities.  Details
>will be published to the dev mailing list.
>On Jun 11, 2013, at 2:08 AM, Min Chen <> wrote:
>> It is 11th June. John is not free between 9:15am to 10am, that is why we
>> schedule it at 10:30am.
>> Thanks
>> -min
>> On 6/10/13 10:52 PM, "Nitin Mehta" <> wrote:
>>> Hi Min,
>>> When you say tomorrow, what date is it 11th June or 12th ? Can the
>>>time be
>>> preponed by an hour please - its too late here ?
>>> Thanks,
>>> -Nitin
>>> On 11/06/13 11:06 AM, "Min Chen" <> wrote:
>>>> Hi there,
>>>> To reach consensus on some remaining NFS cache issues on object_store
>>>> storage refactor work in a more effective manner, John, Edison and I
>>>> scheduled a GoToMeeting tomorrow to discuss them over the phone, any
>>>> interested parties are welcome to join and brainstorm. Here are
>>>> GTM information:
>>>> Meeting Time: 10:30 AM ­ 12:30 PM PST
>>>> Meeting Details:
>>>> 1.  Please join my meeting.
>>>> 2.  Use your microphone and speakers (VoIP) - a headset is
>>>> Or, call in using your telephone.
>>>> United States: +1 (626) 521-0017
>>>> United States (toll-free): 1 877 309 2070
>>>> Access Code: 188-620-897
>>>> Audio PIN: Shown after joining the meeting
>>>> Meeting ID: 188-620-897
>>>> GoToMeeting®
>>>> Online Meetings Made Easy®
>>>> Not at your computer? Click the link to join this meeting from your
>>>> iPhone®, iPad® or Android® device via the GoToMeeting app.
>>>> Thanks
>>>> -min

View raw message