<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Sep 19, 2016 at 10:13 AM, Niels de Vos <span dir="ltr"><<a href="mailto:ndevos@redhat.com" target="_blank">ndevos@redhat.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On Tue, Sep 13, 2016 at 12:06:00PM -0400, Luis Pabón wrote:<br>
> Very good points. Thanks Prasanna for putting this together. I agree with<br>
> your comments in that Heketi is the high level abstraction API and it should have<br>
> an API similar of what is described by Prasanna.<br>
><br>
> I definitely do not think any File Api should be available in Heketi,<br>
> because that is an implementation of the Block API. The Heketi API should<br>
> be similar to something like OpenStack Cinder.<br>
><br>
> I think that the actual management of the Volumes used for Block storage<br>
> and the files in them should be all managed by Heketi. How they are<br>
> actually created is still to be determined, but we could have Heketi<br>
> create them, or have helper programs do that.<br>
<br>
</span>Maybe a tool like qemu-img? If whatever iscsi service understand the<br>
format (at the very least 'raw'), you could get functionality like<br>
snapshots pretty simple.<br></blockquote><div><br></div><div>Prasanna, Poornima and I just discussed about this. Prasanna is doing this experiment to see if we can use qcow from tcmu-runner to get this piece working. If yes, we definitely will get snapshots for free :-). Prasanna will confirm it based on his experiments.<br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<span class="HOEnZb"><font color="#888888"><br>
Niels<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
<br>
> We also need to document the exact workflow to enable a file in<br>
> a Gluster volume to be exposed as a block device. This will help<br>
> determine where the creation of the file could take place.<br>
><br>
> We can capture our decisions from these discussions in the<br>
> following page:<br>
><br>
> <a href="https://github.com/heketi/heketi/wiki/Proposed-Changes" rel="noreferrer" target="_blank">https://github.com/heketi/<wbr>heketi/wiki/Proposed-Changes</a><br>
><br>
> - Luis<br>
><br>
><br>
> ----- Original Message -----<br>
> From: "Humble Chirammal" <<a href="mailto:hchiramm@redhat.com">hchiramm@redhat.com</a>><br>
> To: "Raghavendra Talur" <<a href="mailto:rtalur@redhat.com">rtalur@redhat.com</a>><br>
> Cc: "Prasanna Kalever" <<a href="mailto:pkalever@redhat.com">pkalever@redhat.com</a>>, "gluster-devel" <<a href="mailto:gluster-devel@gluster.org">gluster-devel@gluster.org</a>>, "Stephen Watt" <<a href="mailto:swatt@redhat.com">swatt@redhat.com</a>>, "Luis Pabon" <<a href="mailto:lpabon@redhat.com">lpabon@redhat.com</a>>, "Michael Adam" <<a href="mailto:madam@redhat.com">madam@redhat.com</a>>, "Ramakrishna Yekulla" <<a href="mailto:rreddy@redhat.com">rreddy@redhat.com</a>>, "Mohamed Ashiq Liyazudeen" <<a href="mailto:mliyazud@redhat.com">mliyazud@redhat.com</a>><br>
> Sent: Tuesday, September 13, 2016 2:23:39 AM<br>
> Subject: Re: [Gluster-devel] [Heketi] Block store related API design discussion<br>
><br>
><br>
><br>
><br>
><br>
> ----- Original Message -----<br>
> | From: "Raghavendra Talur" <<a href="mailto:rtalur@redhat.com">rtalur@redhat.com</a>><br>
> | To: "Prasanna Kalever" <<a href="mailto:pkalever@redhat.com">pkalever@redhat.com</a>><br>
> | Cc: "gluster-devel" <<a href="mailto:gluster-devel@gluster.org">gluster-devel@gluster.org</a>>, "Stephen Watt" <<a href="mailto:swatt@redhat.com">swatt@redhat.com</a>>, "Luis Pabon" <<a href="mailto:lpabon@redhat.com">lpabon@redhat.com</a>>,<br>
> | "Michael Adam" <<a href="mailto:madam@redhat.com">madam@redhat.com</a>>, "Humble Chirammal" <<a href="mailto:hchiramm@redhat.com">hchiramm@redhat.com</a>>, "Ramakrishna Yekulla"<br>
> | <<a href="mailto:rreddy@redhat.com">rreddy@redhat.com</a>>, "Mohamed Ashiq Liyazudeen" <<a href="mailto:mliyazud@redhat.com">mliyazud@redhat.com</a>><br>
> | Sent: Tuesday, September 13, 2016 11:08:44 AM<br>
> | Subject: Re: [Gluster-devel] [Heketi] Block store related API design discussion<br>
> |<br>
> | On Mon, Sep 12, 2016 at 11:30 PM, Prasanna Kalever <<a href="mailto:pkalever@redhat.com">pkalever@redhat.com</a>><br>
> | wrote:<br>
> |<br>
> | > Hi all,<br>
> | ><br>
> | > This mail is open for discussion on gluster block store integration with<br>
> | > heketi and its REST API interface design constraints.<br>
> | ><br>
> | ><br>
> | > ___ Volume Request ...<br>
> | > |<br>
> | > |<br>
> | > PVC claim -> Heketi --->|<br>
> | > |<br>
> | > |<br>
> | > |<br>
> | > |<br>
> | > | __ BlockCreate<br>
> | > | |<br>
> | > | |__ BlockInfo<br>
> | > | |<br>
> | > |___ Block Request (APIS)-> |__ BlockResize<br>
> | > |<br>
> | > |__ BlockList<br>
> | > |<br>
> | > |__ BlockDelete<br>
> | ><br>
> | > Heketi will have block API and volume API, when user submit a Persistent<br>
> | > volume claim, Kubernetes provisioner based on the storage class(from PVC)<br>
> | > talks to heketi for storage, heketi intern calls block or volume API's<br>
> | > based on request.<br>
> | ><br>
> |<br>
> | This is probably wrong. It won't be Heketi calling block or volume APIs. It<br>
> | would be Kubernetes calling block or volume API *of* Heketi.<br>
> |<br>
> |<br>
> | > With my limited understanding, heketi currently creates clusters from<br>
> | > provided nodes, creates volumes and handover them to the user.<br>
> | > For block related API's, it has to deal with files right ?<br>
> | ><br>
> | > Here is how block API's look like in short-<br>
> | > Create: heketi has to create file in the volume and export it as a iscsi<br>
> | > target device and hand it over to user.<br>
> | > Info: show block stores information across all the clusters, connection<br>
> | > info, size etc.<br>
> | > resize: resize the file in the volume, refresh connections from initiator<br>
> | > side<br>
> | > List: List the connections<br>
> | > Delete: logout the connections and delete the file in the gluster volume<br>
> | ><br>
> | > Couple of questions:<br>
> | > 1. Should Block API have sub API's such as FileCreate, FileList,<br>
> | > FileResize, File delete and etc then get it used in Block API as they<br>
> | > mostly deal with files.<br>
> | ><br>
> |<br>
> | IMO, Heketi should not expose any File related API. It should only have<br>
> | APIs to service request for block devices; how the block devices are<br>
> | created and modified is an implementation detail.<br>
> |<br>
> |<br>
> | > 2. How do we create the actual file in the volume, meaning using FUSE<br>
> | > mount (which may involve an extra process running) or gfapi, again if gfapi<br>
> | > should we go with c API's, python bindings or go bindings ?<br>
> | ><br>
> | 3. Should we get targetcli related (LUN exporting) setup done from heketi<br>
> | > or do we seek help from gdeploy for this ?<br>
> | ><br>
> |<br>
> | I would prefer to either have it in Heketi or in Kubernetes. If the API in<br>
> | Heketi promises just the creation of block device, then the rest of the<br>
> | implementation should be in Kubernetes(the export part). If the API in<br>
> | Heketi promises create and export both, I would say Heketi should have the<br>
> | implementation within itself.<br>
> |<br>
> |<br>
><br>
> IMO, we should not think about how the clients ( ex: k8s) use it, because there may be different clients.<br>
> We should concentrate mainly on 'in/out' of block API in Heketi. Regardless of which client, the API should act the same way.<br>
><br>
> --Humble<br>
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<a href="http://www.gluster.org/mailman/listinfo/gluster-devel" rel="noreferrer" target="_blank">http://www.gluster.org/<wbr>mailman/listinfo/gluster-devel</a><br></blockquote></div><br><br clear="all"><br>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Pranith<br></div></div>
</div></div>