)]}'
{"doc/source/overview_erasure_code.rst":[{"author":{"_account_id":7233,"name":"Matthew Oliver","email":"matt@oliver.net.au","username":"mattoliverau"},"change_message_id":"a3574adca6431a79e601e1e9d2ae91aa0bca6b6a","unresolved":false,"context_lines":[{"line_number":272,"context_line":"across regions is inefficent, and rebalance unoptimized accross high latency"},{"line_number":273,"context_line":"bandwidth constrained WANs."},{"line_number":274,"context_line":""},{"line_number":275,"context_line":".. warning::"},{"line_number":276,"context_line":""},{"line_number":277,"context_line":"    Region support for EC polices is under developement!"},{"line_number":278,"context_line":""}],"source_content_type":"text/x-rst","patch_set":2,"id":"fa31d9ce_bc3bb237","line":275,"range":{"start_line":275,"start_character":0,"end_line":275,"end_character":12},"updated":"2017-02-17 04:59:39.000000000","message":"I wonder if this warning should actually be in the next section. Only because the \u0027EC Duplication\u0027 title makes it a link, selecting it means you bypass this warning:\n\n  http://docs-draft.openstack.org/13/432513/2/check/gate-swift-docs-ubuntu-xenial/0a13472//doc/build/html/overview_erasure_code.html#ec-duplication","commit_id":"dfcaaeb36914886c52e410d5eee7b8441ed73580"},{"author":{"_account_id":1179,"name":"Clay Gerrard","email":"clay.gerrard@gmail.com","username":"clay-gerrard"},"change_message_id":"010c0aefa9c67df0ab8d408913cc242b9ab848d2","unresolved":false,"context_lines":[{"line_number":272,"context_line":"across regions is inefficent, and rebalance unoptimized accross high latency"},{"line_number":273,"context_line":"bandwidth constrained WANs."},{"line_number":274,"context_line":""},{"line_number":275,"context_line":".. warning::"},{"line_number":276,"context_line":""},{"line_number":277,"context_line":"    Region support for EC polices is under developement!"},{"line_number":278,"context_line":""}],"source_content_type":"text/x-rst","patch_set":2,"id":"fa31d9ce_192f543f","line":275,"in_reply_to":"fa31d9ce_bc3bb237","updated":"2017-02-17 17:50:38.000000000","message":"oh... good point... yeah maybe - or two warnings?  dunno :\\\n\nIt\u0027s not really duplications fault that global EC doesn\u0027t work - it\u0027s one of the few parts that works right!\n\n... sigh ... landing not finished stuff is hard :\u0027(","commit_id":"dfcaaeb36914886c52e410d5eee7b8441ed73580"},{"author":{"_account_id":7233,"name":"Matthew Oliver","email":"matt@oliver.net.au","username":"mattoliverau"},"change_message_id":"a3574adca6431a79e601e1e9d2ae91aa0bca6b6a","unresolved":false,"context_lines":[{"line_number":311,"context_line":"        ec_object_segment_size \u003d 1048576"},{"line_number":312,"context_line":"        ec_duplication_factor \u003d 2"},{"line_number":313,"context_line":""},{"line_number":314,"context_line":"In this example a ``10+4`` and duplication factor of 2 (``10+4x2``) will store"},{"line_number":315,"context_line":"28 fragments.  The ring for this policy should be configured with 28 replicas"},{"line_number":316,"context_line":"(i.e.  ``(ec_num_data_fragments + ec_num_parity_fragments) *"},{"line_number":317,"context_line":"ec_duplication_factor``).  A ``10+4x2`` schema **can** allow a multi-region"}],"source_content_type":"text/x-rst","patch_set":2,"id":"fa31d9ce_1c8e7e27","line":314,"range":{"start_line":314,"start_character":58,"end_line":314,"end_character":64},"updated":"2017-02-17 04:59:39.000000000","message":"Order of operations here means this would equal 18 not 28. Needs to be:\n\n  (10+4)x2","commit_id":"dfcaaeb36914886c52e410d5eee7b8441ed73580"},{"author":{"_account_id":1179,"name":"Clay Gerrard","email":"clay.gerrard@gmail.com","username":"clay-gerrard"},"change_message_id":"010c0aefa9c67df0ab8d408913cc242b9ab848d2","unresolved":false,"context_lines":[{"line_number":311,"context_line":"        ec_object_segment_size \u003d 1048576"},{"line_number":312,"context_line":"        ec_duplication_factor \u003d 2"},{"line_number":313,"context_line":""},{"line_number":314,"context_line":"In this example a ``10+4`` and duplication factor of 2 (``10+4x2``) will store"},{"line_number":315,"context_line":"28 fragments.  The ring for this policy should be configured with 28 replicas"},{"line_number":316,"context_line":"(i.e.  ``(ec_num_data_fragments + ec_num_parity_fragments) *"},{"line_number":317,"context_line":"ec_duplication_factor``).  A ``10+4x2`` schema **can** allow a multi-region"}],"source_content_type":"text/x-rst","patch_set":2,"id":"fa31d9ce_59f62cfa","line":314,"in_reply_to":"fa31d9ce_1c8e7e27","updated":"2017-02-17 17:50:38.000000000","message":"yeah but that *looks* stupid\n\n\"a ten plus four times two\" just *sounds* awesome - it\u0027s not really a math equation - it\u0027s just a short-hand description of the policy type - like saying RAID50 is acctually striping (i.e. RAID0) across multiple RAID5 sets - but saying RAID0+5 would *would just be dumb*","commit_id":"dfcaaeb36914886c52e410d5eee7b8441ed73580"},{"author":{"_account_id":7847,"name":"Alistair Coles","email":"alistairncoles@gmail.com","username":"acoles"},"change_message_id":"60857aee4a748d9e93edc1ee95bda24b15de5679","unresolved":false,"context_lines":[{"line_number":311,"context_line":"        ec_object_segment_size \u003d 1048576"},{"line_number":312,"context_line":"        ec_duplication_factor \u003d 2"},{"line_number":313,"context_line":""},{"line_number":314,"context_line":"In this example a ``10+4`` and duplication factor of 2 (``10+4x2``) will store"},{"line_number":315,"context_line":"28 fragments.  The ring for this policy should be configured with 28 replicas"},{"line_number":316,"context_line":"(i.e.  ``(ec_num_data_fragments + ec_num_parity_fragments) *"},{"line_number":317,"context_line":"ec_duplication_factor``).  A ``10+4x2`` schema **can** allow a multi-region"}],"source_content_type":"text/x-rst","patch_set":2,"id":"9a30ddce_9d498f8e","line":314,"in_reply_to":"fa31d9ce_59f62cfa","updated":"2017-03-07 15:23:54.000000000","message":"Done","commit_id":"dfcaaeb36914886c52e410d5eee7b8441ed73580"},{"author":{"_account_id":1179,"name":"Clay Gerrard","email":"clay.gerrard@gmail.com","username":"clay-gerrard"},"change_message_id":"010c0aefa9c67df0ab8d408913cc242b9ab848d2","unresolved":false,"context_lines":[{"line_number":314,"context_line":"In this example a ``10+4`` and duplication factor of 2 (``10+4x2``) will store"},{"line_number":315,"context_line":"28 fragments.  The ring for this policy should be configured with 28 replicas"},{"line_number":316,"context_line":"(i.e.  ``(ec_num_data_fragments + ec_num_parity_fragments) *"},{"line_number":317,"context_line":"ec_duplication_factor``).  A ``10+4x2`` schema **can** allow a multi-region"},{"line_number":318,"context_line":"deployment to rebuild an object to full durability even when *more* than 14"},{"line_number":319,"context_line":"fragments are unavailable.  This has a discreet advantage over a ``10+18``"},{"line_number":320,"context_line":"configuration not only because reads from data fragments will be more common"}],"source_content_type":"text/x-rst","patch_set":2,"id":"fa31d9ce_99d8a481","line":317,"updated":"2017-02-17 17:50:38.000000000","message":"we have the math here explaining how to understand this shorthand for the nerds :P","commit_id":"dfcaaeb36914886c52e410d5eee7b8441ed73580"},{"author":{"_account_id":7847,"name":"Alistair Coles","email":"alistairncoles@gmail.com","username":"acoles"},"change_message_id":"60857aee4a748d9e93edc1ee95bda24b15de5679","unresolved":false,"context_lines":[{"line_number":314,"context_line":"In this example a ``10+4`` and duplication factor of 2 (``10+4x2``) will store"},{"line_number":315,"context_line":"28 fragments.  The ring for this policy should be configured with 28 replicas"},{"line_number":316,"context_line":"(i.e.  ``(ec_num_data_fragments + ec_num_parity_fragments) *"},{"line_number":317,"context_line":"ec_duplication_factor``).  A ``10+4x2`` schema **can** allow a multi-region"},{"line_number":318,"context_line":"deployment to rebuild an object to full durability even when *more* than 14"},{"line_number":319,"context_line":"fragments are unavailable.  This has a discreet advantage over a ``10+18``"},{"line_number":320,"context_line":"configuration not only because reads from data fragments will be more common"}],"source_content_type":"text/x-rst","patch_set":2,"id":"9a30ddce_bd5e5343","line":317,"in_reply_to":"fa31d9ce_99d8a481","updated":"2017-03-07 15:23:54.000000000","message":"Done","commit_id":"dfcaaeb36914886c52e410d5eee7b8441ed73580"},{"author":{"_account_id":4608,"name":"Kota Tsuyuzaki","email":"bloodeagle40234@gmail.com","username":"tsuyuzaki-kota"},"change_message_id":"f5719cef16afc764e8dc24cc975442b4c68cd9d4","unresolved":false,"context_lines":[{"line_number":332,"context_line":"result in ``(10+4)x2 \u003d 28`` fragments being stored (we will use the shorthand"},{"line_number":333,"context_line":"``10+4x2`` to denote that policy configuration) .  The ring for this policy"},{"line_number":334,"context_line":"should be configured with 28 replicas (i.e.  ``(ec_num_data_fragments +"},{"line_number":335,"context_line":"ec_num_parity_fragments) * ec_duplication_factor``).  A ``10+4x2`` schema"},{"line_number":336,"context_line":"**can** allow a multi-region deployment to rebuild an object to full durability"},{"line_number":337,"context_line":"even when *more* than 14 fragments are unavailable.  This is advantageous with"},{"line_number":338,"context_line":"respect to a ``10+18`` configuration not only because reads from data fragments"}],"source_content_type":"text/x-rst","patch_set":4,"id":"9a30ddce_1b674626","line":335,"range":{"start_line":335,"start_character":58,"end_line":335,"end_character":65},"updated":"2017-03-08 06:03:54.000000000","message":"ah, ok. This is the shorthand expression described at L332-L333. Make sense.","commit_id":"38b99ad19579e26248ad4e878bb7c93ea0c64ed1"}]}