Re: [openstack-dev] how to write python object in openstack swift

2017-10-05 Thread Jialin Liu
Hi John, That indeed helped. But I'm stuck in using the python interface to make it work: _opts = {'object_uu_threads': 10, 'segment_size': 1048576} with SwiftService(options=_opts) as swift: Seems not working. Also my another question is about the relationship with uu_threads and segment, my

Re: [openstack-dev] how to write python object in openstack swift

2017-10-05 Thread John Dickinson
I'm not familiar with that format, but in general, if you're dealing with large objects, you can get better performance by splitting the data in the client, uploading each separate segment concurrently, and then creating a large object manifest to tie the segments together (allowing future

Re: [openstack-dev] how to write python object in openstack swift

2017-10-05 Thread Jialin Liu
Thank you John, I think I figured out the way. My case is a little bit rare as I'm dealing with the HDF5 file format, I can not think of any way to retrieve the entire in memory file as a single python object and then serialize it. What I did is to use the hdf5.get_file_image function to get a

Re: [openstack-dev] how to write python object in openstack swift

2017-10-05 Thread John Dickinson
If you've got an arbitrary object in Python, you'll need to serialize it to a file-like object. You could keep it in memory and use a `StringIO` type, or you could serialize it to disk and `open()` it like any other file. Ultimately, Swift is storing arbitrary bytes and doesn't care what they

[openstack-dev] how to write python object in openstack swift

2017-10-05 Thread Jialin Liu
Hi, It seems to me that openstack swift only supports file upload/download, is it possible to put a python object to swift store? The doc says we could use file-like object, e.g., StringIO, but this is very limited. I'd like to write a numpy array or other python object into the swift store, can