For streaming large (greater than 1GB) WebM videos, support for the "Accept-Ranges: bytes" header indicates to the browser that partial content requests are supported. This allows the viewer to jump around the video without having to wait for the whole video to load.

To see this in action, take a large (greater than 1 GB) WebM file and load it onto Mediagoblin, and then try to watch it from the middle. Use the download link to open the video in its own browser tab, and try to watch it in the middle. Again, it will hang for a long time as the data buffers. If you use browser tools to examine the request, the request will have one HTTP 200 response.

Host the same video on nginx and watch it through the browser. You will be able to jump around the content as you like. If you examine the network traffic, there will be an HTTP 200 response for the first request and then HTTP 206 Partial Content responses for each click to navigate.

I'm going to try to figure this out myself, but Python isn't my normal playground. A Mediagoblin developer will probably be much faster.

I've got a test instance using the sqlite backend. I recently updated to current master and tried to run dbupdate. I received the error below.

(mediagoblin-dev) ~/mediagoblin-dev $ bin/gmg dbupdate
/path/to/mediagoblin/mediagoblin/media_types/video/transcoders.py:37: PyGIWarning: GstPbutils was imported without specifying a version first. Use gi.require_version('GstPbutils', '1.0') before import to ensure that the right version gets loaded.
  from gi.repository import GstPbutils
/path/to/mediagoblin/lib/python2.7/site-packages/SQLAlchemy-0.8.7-py2.7-linux-x86_64.egg/sqlalchemy/engine/default.py:459: SAWarning: Unicode type received non-unicode bind param value.
INFO  [alembic.migration] Context impl SQLiteImpl.
INFO  [alembic.migration] Will assume non-transactional DDL.
INFO  [alembic.migration] Running upgrade 101510e3a713 -> 8429e33fdf7, Remove the Graveyard objects from CommentNotification objects
Traceback (most recent call last):
  File "bin/gmg", line 9, in <module>
    load_entry_point('mediagoblin', 'console_scripts', 'gmg')()
  File "/path/to/mediagoblin/mediagoblin/gmg_commands/__init__.py", line 142, in main_cli
    args.func(args)
  File "/path/to/mediagoblin/mediagoblin/gmg_commands/dbupdate.py", line 162, in dbupdate
    run_dbupdate(app_config, global_config)
  File "/path/to/mediagoblin/mediagoblin/gmg_commands/dbupdate.py", line 134, in run_dbupdate
    run_alembic_migrations(db, app_config, global_config)
  File "/path/to/mediagoblin/mediagoblin/gmg_commands/dbupdate.py", line 116, in run_alembic_migrations
    manager.init_or_migrate()
  File "/path/to/mediagoblin/mediagoblin/db/migration_tools.py", line 84, in init_or_migrate
    self.upgrade(version)
  File "/path/to/mediagoblin/mediagoblin/db/migration_tools.py", line 60, in upgrade
    return command.upgrade(self.alembic_cfg, version or 'head')
  File "/path/to/mediagoblin/lib/python2.7/site-packages/alembic-0.6.6-py2.7.egg/alembic/command.py", line 125, in upgrade
    script.run_env()
  File "/path/to/mediagoblin/lib/python2.7/site-packages/alembic-0.6.6-py2.7.egg/alembic/script.py", line 203, in run_env
    util.load_python_file(self.dir, 'env.py')
  File "/path/to/mediagoblin/lib/python2.7/site-packages/alembic-0.6.6-py2.7.egg/alembic/util.py", line 215, in load_python_file
    module = load_module_py(module_id, path)
  File "/path/to/mediagoblin/lib/python2.7/site-packages/alembic-0.6.6-py2.7.egg/alembic/compat.py", line 58, in load_module_py
    mod = imp.load_source(module_id, path, fp)
  File "/path/to/mediagoblin/mediagoblin/db/migrations/env.py", line 62, in <module>
    run_migrations_online()
  File "/path/to/mediagoblin/mediagoblin/db/migrations/env.py", line 57, in run_migrations_online
    context.run_migrations()
  File "<string>", line 7, in run_migrations
  File "/path/to/mediagoblin/lib/python2.7/site-packages/alembic-0.6.6-py2.7.egg/alembic/environment.py", line 689, in run_migrations
    self.get_context().run_migrations(**kw)
  File "/path/to/mediagoblin/lib/python2.7/site-packages/alembic-0.6.6-py2.7.egg/alembic/migration.py", line 263, in run_migrations
    change(**kw)
  File "/path/to/mediagoblin/mediagoblin/db/migrations/versions/8429e33fdf7_remove_the_graveyard_objects_from_.py", line 45, in upgrade
    notification_table.c.object_id == gmr.id
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 1614, in execute
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 662, in execute
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 761, in _execute_clauseelement
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 908, in _execute_context
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 491, in _commit_impl
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 1024, in _handle_dbapi_exception
  File "build/bdist.linux-x86_64/egg/sqlalchemy/util/compat.py", line 196, in raise_from_cause
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 488, in _commit_impl
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/default.py", line 297, in do_commit
sqlalchemy.exc.OperationalError: (OperationalError) database is locked None None

It would seem Paste now supports Python3 (​source here). If we move back we can solve some issues we are having with gunircorn such as the one in #978.

It would seem since version 2.0 of Paste it's had experemental python 3 support, the 2.0.1 and 2.0.2 build on that.