Re: [Engine-devel] Gluster Volume asynchronous tasks

On 08/12/2013 03:28 PM, Yair Zaslavsky wrote: > > ----- Original Message ----- >> From: "Sahina Bose" <sabose(a)redhat.com&gt; >> To: "Eli Mesika" <emesika(a)redhat.com&gt; >> Cc: "engine-devel" <engine-devel(a)ovirt.org&gt;, arch(a)ovirt.org >> Sent: Monday, August 12, 2013 11:51:15 AM >> Subject: Re: [Engine-devel] Gluster Volume asynchronous tasks >> >> >> On 08/12/2013 01:21 PM, Eli Mesika wrote: >>> ----- Original Message ----- >>>> From: "Sahina Bose" <sabose(a)redhat.com&gt; >>>> To: "engine-devel" <engine-devel(a)ovirt.org&gt;, arch(a)ovirt.org, "Michael >>>> Pasternak" <mpastern(a)redhat.com&gt; >>>> Sent: Monday, August 12, 2013 8:41:55 AM >>>> Subject: [Engine-devel] Gluster Volume asynchronous tasks >>>> >>>> Hi all, >>>> >>>> We are working on a feature to add support to start and monitor >>>> gluster >>>> volume asynchronous tasks (like rebalancing a gluster volume, removing >>>> brick from volume ) from the oVirt engine. >>>> >>>> The operations can be started from the Volumes tab or the Bricks >>>> sub-tab >>>> using the Rebalance, Remove options. >>>> These are long running operations which can be monitored using a >>>> task id >>>> returned from Gluster. We are planning to add the monitoring in the >>>> existing Task sub tab >>>> >>>> The feature description and User flows are at >>>> http://www.ovirt.org/Features/Gluster_Volume_Asynchronous_Tasks_Management >>>> >>>> >>>> The detailed design (including REST API design) is at >>>> http://www.ovirt.org/Features/Detailed_Gluster_Volume_Asynchronous_Tasks_.... >>>> >>>> >>>> I would really appreciate if you could review and provide your >>>> valuable >>>> feedback. >>> I Sahina >>> Why not using 6the External Tasks feature introduced for 3.3 for those >>> Gluster tasks ??? >>> http://www.ovirt.org/Features/Design/DetailedExternalTasks >> Hi Eli, >> >> We still want to be able to start and stop these operations from the >> engine. >> So, when a user wants to say, rebalance a volume, they would go select >> the volume and click on Rebalance Start. >> This would then call the BLL command to start rebalance which will >> invoke the corresponding vdsm verb to start the rebalance on the volume. >> This is the same as existing flow for other commands. The only >> difference is the vdsm verb will return the task id from gluster, for >> the rebalance operation that was started. And we will monitor the >> progress of the task using the gluster task id (by calling a gluster >> command) >> >> I'm not sure how ExternalTasks would fit in here? I was thinking of >> using ExternalTask support for adding Job/Steps to engine when the >> operation is started outside of engine, that is, from Gluster CLI. >> Please correct me if I'm missing something. > Does this mean that from Gluster CLI you will not try and invoke the > rebalance command ? > (I mean, I should either use Gluster CLI or Engine's REST API?) Rebalance volume command could be invoked in any of the following ways: 1. From the console UI (clicking on Rebalance as shown in http://www.ovirt.org/Features/Gluster_Volume_Asynchronous_Tasks_Managemen...) 2. Using REST API 3. Outside of engine, from Gluster CLI - In such cases, the engine should detect that a user has triggered rebalance operation outside the engine, and allow the user to monitor progress of this from the engine. This is where, we need support to add a Job for an operation that was started externally, so that it can be seen in the Tasks tab.