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From Nitin Mehta <>
Subject Re: new storage framework update
Date Wed, 09 Jan 2013 17:22:39 GMT
Hi Edison,

Thanks for the update and appreciate your hard work on this. Could you
please illustrate the jargons (example primaryDataStoreConfigurator,
lifecycycle, driver class etc.) you introduced with examples and flow
diagrams for better understanding. I went through the code (I think its
undergoing merge so couldn't navigate through the flow smoothly), wiki,
pdfs etc. but need a bigger picture view of the work, interactions among
different components and what each of them mean. Can you share a detailed
write up and also the collab video for your talk as well ?

Also about the functionalities you implemented as mentioned in #2 below
can you please explain in detail ? Do we still use SSVM ? What are the
changed functionalities and what has been thrown away ?


On 28/12/12 8:11 AM, "Edison Su" <> wrote:

>Hi All, 
>     Before heading into holiday, I'd like to update the current status
>of the new storage framework since last collab12.
>    1. Class diagram of primary storage is evolved:
>          Highlight the current design:
>          a.  One storage provider can cover multiple storage protocols
>for multiple hypervisors. The default storage provider can almost cover
>all the current primary storage protocols. In most of cases, you don't
>need to write a new storage provider, what you need to do is to write a
>new storage configurator. Write a new storage provider needs to write a
>lot of code, which we should avoid it as much as possible.
>         b. A new type hierarchy, primaryDataStoreConfigurator, is added.
>The configurator is a factory for primaryDataStore, which assemble
>StorageProtocolTransformer, PrimaryDataStoreLifeCycle and
>PrimaryDataStoreDriver for PrimaryDataStore object, based on the
>hypervisor type and the storage protocol.  For example, for nfs primary
>storage on xenserver, there is a class called XenNfsConfigurator, which
>put DefaultXenPrimaryDataStoreLifeCycle, NfsProtocolTransformer and
>DefaultPrimaryDataStoreDriverImpl into DefaultPrimaryDataStore. One
>provider can only have one configurator for a pair of hypervisor type and
>storage protocol. For example, if you want to add a new nfs protocol
>configurator for xenserver hypervisor, you need to write a new storage
>        c. A new interface, StorageProtocolTransformer, is added. The
>main purpose of this interface is to handle the difference between
>different storage protocols. It has four methods:
>             getInputParamNames: return a list of name of parameters for
>a particular protocol. E.g. NFS protocol has ["server", "path"], ISCSI
>has ["iqn", "lun"] etc. UI shouldn't hardcode these parameters any more.
>             normalizeUserInput: given a user input from UI/API, need to
>validate the input, and break it apart, then store them into database
>             getDataStoreTO/ getVolumeTO: each protocol can have its own
>volumeTO and primaryStorageTO. TO is the object will be passed down to
>resource, if your storage has extra information you want to pass to
>resource, these two methods are the place you can override.
>        d. All the time-consuming API calls related to storage is async.
>       2. Minimal functionalities are implemented:
>            a. Can register a http template, without SSVM
>            b. Can register a NFS primary storage for xenserver
>            c. Can download a template into primary storage directly
>           d. Can create a volume from a template
>       3. All about test:
>           a. TestNG test framework is used, as it can provide parameter
>for each test case. For integration test, we need to know ip address of
>hypervisor host, the host uuid(if it's xenserver), the primary storage
>url, the template url etc. These configurations are better to be
>parameterized, so for each test run, we don't need to modify test case
>itself, instead, we provide a test configuration file for each test run.
>TestNG framework already has this functionality, I just reuse it.
>           b. Every pieces of code can be unit tested, which means:
>                 b.1 the xcp plugin can be unit tested. I wrote a small
>python code, called, which can directly call xcp plugin.
>                 b.2 direct agent hypervisor resource can be tested. I
>wrote a mock agent manger, which can load and initialize hypervisor
>resource, and also can send command to resource.
>                 b.3 a storage integration test maven project is created,
>which can test the whole storage subsystem, such as create volume from
>template, which including both image and volume components.
>           A new section, called "how to test", is added into
>.0, please check it out.
>      The code is on the javelin branch, the maven projects whose name
>starting from cloud-engine-storage-* are the code related to storage
>subsystem. Most of the primary storage code is in
>cloud-engine-storage-volume project.
>       Any feedback/comment is appreciated. 

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