diff --git a/src/list/raxos/Abstract Paxos Diagram.canvas b/src/list/raxos/Abstract Paxos Diagram.canvas index a13b77d..26a07c4 100644 --- a/src/list/raxos/Abstract Paxos Diagram.canvas +++ b/src/list/raxos/Abstract Paxos Diagram.canvas @@ -8,14 +8,9 @@ {"id":"707de0dee3c23555","type":"file","file":"consensus-essence/src/list/raxos/example-T-in-single-threaded.md","x":1580,"y":820,"width":400,"height":400,"color":"5"}, {"id":"b553044d1b09bc14","type":"file","file":"consensus-essence/src/list/raxos/def-API-read-write.md","x":1184,"y":1432,"width":400,"height":400}, {"id":"11003bbfc4ff8328","type":"file","file":"consensus-essence/src/list/raxos/def-T-History-PartialOrd.md","x":420,"y":1320,"width":465,"height":238}, - {"id":"9c32627fede27385","type":"file","file":"consensus-essence/src/list/raxos/example-RW-single-threaded.md","x":1780,"y":1960,"width":400,"height":400,"color":"5"}, - {"id":"6f61f61fbd369e9a","type":"file","file":"consensus-essence/src/list/raxos/def-Past-Future.md","x":720,"y":2200,"width":400,"height":400}, - {"id":"ebae8b958fa8ef58","type":"file","file":"consensus-essence/src/list/raxos/example-Past-Future-distributed.md","x":1120,"y":3260,"width":400,"height":400,"color":"5"}, - {"id":"23b7153aa3b72e6d","type":"file","file":"consensus-essence/src/list/raxos/example-Past-Future-single-threaded.md","x":1280,"y":2720,"width":400,"height":400,"color":"5"}, {"id":"23b19f5ffc793d95","type":"file","file":"consensus-essence/src/list/raxos/def-Apply.md","x":1002,"y":3,"width":400,"height":400}, {"id":"6d2f40704a61e31b","type":"file","file":"consensus-essence/src/list/raxos/def-Sub-History.md","x":-160,"y":1120,"width":400,"height":400}, {"id":"09a5660b835acde1","type":"file","file":"consensus-essence/src/list/raxos/def-Mergeable-History.md","x":-160,"y":1760,"width":400,"height":400}, - {"id":"24e816cf21a582e0","type":"file","file":"consensus-essence/src/list/raxos/def-RW-Necessity.md","x":1184,"y":2060,"width":400,"height":400}, {"id":"cc1534fa18215622","type":"file","file":"consensus-essence/src/list/raxos/prop-Merge-Read.md","x":-160,"y":2980,"width":400,"height":400}, {"id":"11ad89cd35a2b1f6","type":"file","file":"consensus-essence/src/list/raxos/def-Distributed-HA.md","x":360,"y":1720,"width":400,"height":400}, {"id":"056ed53ecdd08e9a","type":"file","file":"consensus-essence/src/list/raxos/def-Distributed-Copies.md","x":120,"y":2200,"width":400,"height":400}, @@ -25,21 +20,31 @@ {"id":"97c0f9ab39142bd8","type":"file","file":"consensus-essence/src/list/raxos/prop-Write-Forbid-Smaller.md","x":-464,"y":4224,"width":400,"height":400}, {"id":"2de15b9927901fdf","type":"file","file":"consensus-essence/src/list/raxos/def-Read-Quorum-Set.md","x":640,"y":3778,"width":400,"height":400}, {"id":"75b048956a6d5a4f","type":"file","file":"consensus-essence/src/list/raxos/example-Quorum-Set.md","x":1480,"y":4260,"width":400,"height":400,"color":"5"}, - {"id":"64f0cd59fe29aca7","type":"file","file":"consensus-essence/src/list/raxos/def-Write-Quorum-Set.md","x":640,"y":4360,"width":400,"height":400}, {"id":"8e2e4bdc350b67dd","type":"file","file":"consensus-essence/src/list/raxos/example-Quorum-Set-xy.md","x":1360,"y":4760,"width":400,"height":400,"color":"5"}, - {"id":"eefaf5fc7ce43eba","type":"file","file":"consensus-essence/src/list/raxos/def-Observable-History.md","x":200,"y":4460,"width":400,"height":400}, - {"id":"2aa96775efaf3504","x":0,"y":5100,"width":400,"height":400,"type":"file","file":"consensus-essence/src/list/raxos/def-T-Committed.md"}, - {"id":"b33b510032aaea23","x":0,"y":5660,"width":400,"height":400,"type":"file","file":"consensus-essence/src/list/raxos/def-Committed.md"}, - {"id":"4425d02ad7c436fc","x":1207,"y":5220,"width":400,"height":400,"color":"3","type":"file","file":"consensus-essence/src/list/raxos/desc-Availability.md"}, - {"id":"e17d353216ad61b2","x":-464,"y":6120,"width":400,"height":400,"color":"6","type":"file","file":"consensus-essence/src/list/raxos/protocol-Write-Forbid-Smaller.md"}, - {"id":"4fe24a286d42d5c1","x":0,"y":6400,"width":400,"height":400,"color":"6","type":"file","file":"consensus-essence/src/list/raxos/protocol-Write-After-Read.md"}, - {"id":"64f51b278ec2e315","x":-720,"y":7800,"width":400,"height":400,"color":"6","type":"file","file":"consensus-essence/src/list/raxos/protocol-All.md"}, - {"id":"04445468a553ca25","x":0,"y":7200,"width":400,"height":400,"color":"6","type":"file","file":"consensus-essence/src/list/raxos/protocol-Write-P2.md"}, - {"id":"99fd7ad8ee77b8b7","x":-80,"y":8320,"width":400,"height":400,"color":"5","type":"file","file":"consensus-essence/src/list/raxos/example-Classic-Paxos.md"}, - {"id":"d712fa28e2c9ebae","x":534,"y":8457,"width":400,"height":400,"type":"file","file":"consensus-essence/src/list/raxos/example-Raft.md"}, - {"id":"a74a6a5cfa5647bc","x":-492,"y":9029,"width":400,"height":400,"type":"file","file":"consensus-essence/src/list/raxos/2d-consensus.md"}, - {"id":"5d01e9e3355926b6","x":-297,"y":9810,"width":400,"height":390,"color":"5","type":"file","file":"consensus-essence/src/list/raxos/example-2d-consensus.md"}, - {"id":"877084719c0840fa","x":-323,"y":10613,"width":400,"height":400,"type":"file","file":"consensus-essence/src/list/raxos/def-2d-consensus-Apply.md"} + {"id":"2aa96775efaf3504","type":"file","file":"consensus-essence/src/list/raxos/def-T-Committed.md","x":0,"y":5100,"width":400,"height":400}, + {"id":"b33b510032aaea23","type":"file","file":"consensus-essence/src/list/raxos/def-Committed.md","x":0,"y":5660,"width":400,"height":400}, + {"id":"4425d02ad7c436fc","type":"file","file":"consensus-essence/src/list/raxos/desc-Availability.md","x":1207,"y":5220,"width":400,"height":400,"color":"3"}, + {"id":"4fe24a286d42d5c1","type":"file","file":"consensus-essence/src/list/raxos/protocol-Write-After-Read.md","x":0,"y":6400,"width":400,"height":400,"color":"6"}, + {"id":"64f51b278ec2e315","type":"file","file":"consensus-essence/src/list/raxos/protocol-All.md","x":-720,"y":7800,"width":400,"height":400,"color":"6"}, + {"id":"04445468a553ca25","type":"file","file":"consensus-essence/src/list/raxos/protocol-Write-P2.md","x":0,"y":7200,"width":400,"height":400,"color":"6"}, + {"id":"99fd7ad8ee77b8b7","type":"file","file":"consensus-essence/src/list/raxos/example-Classic-Paxos.md","x":-80,"y":8320,"width":400,"height":400,"color":"5"}, + {"id":"d712fa28e2c9ebae","type":"file","file":"consensus-essence/src/list/raxos/example-Raft.md","x":534,"y":8457,"width":400,"height":400,"color":"5"}, + {"id":"a74a6a5cfa5647bc","type":"file","file":"consensus-essence/src/list/raxos/2d-consensus.md","x":-492,"y":9029,"width":400,"height":400}, + {"id":"5d01e9e3355926b6","type":"file","file":"consensus-essence/src/list/raxos/example-2d-consensus.md","x":-297,"y":9810,"width":400,"height":390,"color":"5"}, + {"id":"877084719c0840fa","type":"file","file":"consensus-essence/src/list/raxos/def-2d-consensus-Apply.md","x":-323,"y":10613,"width":400,"height":400}, + {"id":"24e816cf21a582e0","type":"file","file":"consensus-essence/src/list/raxos/def-RW-Necessity.md","x":1184,"y":2120,"width":400,"height":400}, + {"id":"6f61f61fbd369e9a","type":"file","file":"consensus-essence/src/list/raxos/def-Past-Future.md","x":1720,"y":2120,"width":400,"height":400}, + {"id":"9c32627fede27385","type":"file","file":"consensus-essence/src/list/raxos/example-RW-single-threaded.md","x":2200,"y":1832,"width":400,"height":400,"color":"5"}, + {"id":"23b7153aa3b72e6d","type":"file","file":"consensus-essence/src/list/raxos/example-Past-Future-single-threaded.md","x":2200,"y":2760,"width":400,"height":400,"color":"5"}, + {"id":"ebae8b958fa8ef58","type":"file","file":"consensus-essence/src/list/raxos/example-Past-Future-distributed.md","x":2200,"y":3320,"width":400,"height":400,"color":"5"}, + {"id":"64f0cd59fe29aca7","type":"file","file":"consensus-essence/src/list/raxos/def-Write-Quorum-Set.md","x":640,"y":4460,"width":400,"height":400}, + {"id":"eefaf5fc7ce43eba","type":"file","file":"consensus-essence/src/list/raxos/def-Observable-History.md","x":160,"y":4460,"width":400,"height":400}, + {"id":"f001ccd718f70347","x":640,"y":5160,"width":400,"height":400,"color":"3","type":"file","file":"consensus-essence/src/list/raxos/desc-History Read Set.md"}, + {"id":"a838cacb9e50352d","x":236,"y":9019,"width":400,"height":400,"color":"5","type":"file","file":"consensus-essence/src/list/raxos/example-crdt.md"}, + {"id":"c55a71983b5140b2","x":722,"y":9578,"width":400,"height":400,"color":"5","type":"file","file":"consensus-essence/src/list/raxos/example-2d-non-transitive-time.md"}, + {"id":"6aca35d4bc6e348f","x":236,"y":10120,"width":400,"height":400,"color":"5","type":"file","file":"consensus-essence/src/list/raxos/exmaple-crdt-define.md"}, + {"id":"e0499dbb83899c24","x":236,"y":10640,"width":400,"height":400,"color":"5","type":"file","file":"consensus-essence/src/list/raxos/example-crdt-implementation.md"}, + {"id":"e17d353216ad61b2","type":"file","file":"consensus-essence/src/list/raxos/protocol-Write-Forbid-Smaller.md","x":-520,"y":6280,"width":400,"height":400,"color":"6"} ], "edges":[ {"id":"ec72236e30d4ad00","fromNode":"6d2f40704a61e31b","fromSide":"bottom","toNode":"09a5660b835acde1","toSide":"top"}, @@ -87,6 +92,12 @@ {"id":"1d3e17e5ee6152bf","fromNode":"64f51b278ec2e315","fromSide":"bottom","toNode":"d712fa28e2c9ebae","toSide":"top"}, {"id":"f6c7441b6af0d177","fromNode":"64f51b278ec2e315","fromSide":"bottom","toNode":"a74a6a5cfa5647bc","toSide":"top"}, {"id":"f9c577da2f0570dd","fromNode":"a74a6a5cfa5647bc","fromSide":"bottom","toNode":"5d01e9e3355926b6","toSide":"top"}, - {"id":"fe61a48ba3c61f1e","fromNode":"5d01e9e3355926b6","fromSide":"bottom","toNode":"877084719c0840fa","toSide":"top"} + {"id":"fe61a48ba3c61f1e","fromNode":"5d01e9e3355926b6","fromSide":"bottom","toNode":"877084719c0840fa","toSide":"top"}, + {"id":"065998b773a58476","fromNode":"eefaf5fc7ce43eba","fromSide":"bottom","toNode":"f001ccd718f70347","toSide":"top"}, + {"id":"ea0a374d1e541e54","fromNode":"64f51b278ec2e315","fromSide":"bottom","toNode":"a838cacb9e50352d","toSide":"top"}, + {"id":"e56beb199a811c22","fromNode":"a838cacb9e50352d","fromSide":"bottom","toNode":"c55a71983b5140b2","toSide":"top"}, + {"id":"b6b5fdb98e3ed393","fromNode":"a838cacb9e50352d","fromSide":"bottom","toNode":"6aca35d4bc6e348f","toSide":"top"}, + {"id":"51d037ce1e9e19b8","fromNode":"c55a71983b5140b2","fromSide":"bottom","toNode":"6aca35d4bc6e348f","toSide":"top"}, + {"id":"37c8ac0a99460eca","fromNode":"6aca35d4bc6e348f","fromSide":"bottom","toNode":"e0499dbb83899c24","toSide":"top"} ] } \ No newline at end of file diff --git a/src/list/raxos/assets/crdt-storage.excalidraw.png b/src/list/raxos/assets/crdt-storage.excalidraw.png new file mode 100644 index 0000000..969bb68 Binary files /dev/null and b/src/list/raxos/assets/crdt-storage.excalidraw.png differ diff --git a/src/list/raxos/assets/crdt-time.excalidraw.png b/src/list/raxos/assets/crdt-time.excalidraw.png new file mode 100644 index 0000000..802b277 Binary files /dev/null and b/src/list/raxos/assets/crdt-time.excalidraw.png differ diff --git a/src/list/raxos/assets/crdt.excalidraw.png b/src/list/raxos/assets/crdt.excalidraw.png new file mode 100644 index 0000000..17fc219 Binary files /dev/null and b/src/list/raxos/assets/crdt.excalidraw.png differ diff --git a/src/list/raxos/history-conflict.excalidraw.png b/src/list/raxos/assets/history-conflict.excalidraw.png similarity index 100% rename from src/list/raxos/history-conflict.excalidraw.png rename to src/list/raxos/assets/history-conflict.excalidraw.png diff --git a/src/list/raxos/history-data-loss.excalidraw.png b/src/list/raxos/assets/history-data-loss.excalidraw.png similarity index 100% rename from src/list/raxos/history-data-loss.excalidraw.png rename to src/list/raxos/assets/history-data-loss.excalidraw.png diff --git a/src/list/raxos/history-dirty-write.excalidraw.png b/src/list/raxos/assets/history-dirty-write.excalidraw.png similarity index 100% rename from src/list/raxos/history-dirty-write.excalidraw.png rename to src/list/raxos/assets/history-dirty-write.excalidraw.png diff --git a/src/list/raxos/history-generalized-time.excalidraw.png b/src/list/raxos/assets/history-generalized-time.excalidraw.png similarity index 100% rename from src/list/raxos/history-generalized-time.excalidraw.png rename to src/list/raxos/assets/history-generalized-time.excalidraw.png diff --git a/src/list/raxos/history-read-set-union.excalidraw.png b/src/list/raxos/assets/history-read-set-union.excalidraw.png similarity index 100% rename from src/list/raxos/history-read-set-union.excalidraw.png rename to src/list/raxos/assets/history-read-set-union.excalidraw.png diff --git a/src/list/raxos/history-read-set.excalidraw.png b/src/list/raxos/assets/history-read-set.excalidraw.png similarity index 100% rename from src/list/raxos/history-read-set.excalidraw.png rename to src/list/raxos/assets/history-read-set.excalidraw.png diff --git a/src/list/raxos/history-singe-thread.excalidraw.png b/src/list/raxos/assets/history-singe-thread.excalidraw.png similarity index 100% rename from src/list/raxos/history-singe-thread.excalidraw.png rename to src/list/raxos/assets/history-singe-thread.excalidraw.png diff --git a/src/list/raxos/assets/history-visible-12.excalidraw.png b/src/list/raxos/assets/history-visible-12.excalidraw.png new file mode 100644 index 0000000..2aac2a7 Binary files /dev/null and b/src/list/raxos/assets/history-visible-12.excalidraw.png differ diff --git a/src/list/raxos/history-visible-123.excalidraw.png b/src/list/raxos/assets/history-visible-123.excalidraw.png similarity index 100% rename from src/list/raxos/history-visible-123.excalidraw.png rename to src/list/raxos/assets/history-visible-123.excalidraw.png diff --git a/src/list/raxos/history.excalidraw.png b/src/list/raxos/assets/history.excalidraw.png similarity index 100% rename from src/list/raxos/history.excalidraw.png rename to src/list/raxos/assets/history.excalidraw.png diff --git a/src/list/raxos/linear-rw.excalidraw.png b/src/list/raxos/assets/linear-rw.excalidraw.png similarity index 100% rename from src/list/raxos/linear-rw.excalidraw.png rename to src/list/raxos/assets/linear-rw.excalidraw.png diff --git a/src/list/raxos/multiverse-read-by-t.excalidraw.png b/src/list/raxos/assets/multiverse-read-by-t.excalidraw.png similarity index 100% rename from src/list/raxos/multiverse-read-by-t.excalidraw.png rename to src/list/raxos/assets/multiverse-read-by-t.excalidraw.png diff --git a/src/list/raxos/multiverse-read-linear.excalidraw.png b/src/list/raxos/assets/multiverse-read-linear.excalidraw.png similarity index 100% rename from src/list/raxos/multiverse-read-linear.excalidraw.png rename to src/list/raxos/assets/multiverse-read-linear.excalidraw.png diff --git a/src/list/raxos/multiverse-rw.excalidraw.png b/src/list/raxos/assets/multiverse-rw.excalidraw.png similarity index 100% rename from src/list/raxos/multiverse-rw.excalidraw.png rename to src/list/raxos/assets/multiverse-rw.excalidraw.png diff --git a/src/list/raxos/past-future-paxos.excalidraw.png b/src/list/raxos/assets/past-future-paxos.excalidraw.png similarity index 100% rename from src/list/raxos/past-future-paxos.excalidraw.png rename to src/list/raxos/assets/past-future-paxos.excalidraw.png diff --git a/src/list/raxos/quorum-2x2.excalidraw.png b/src/list/raxos/assets/quorum-2x2.excalidraw.png similarity index 100% rename from src/list/raxos/quorum-2x2.excalidraw.png rename to src/list/raxos/assets/quorum-2x2.excalidraw.png diff --git a/src/list/raxos/quorum-majority-3.excalidraw.png b/src/list/raxos/assets/quorum-majority-3.excalidraw.png similarity index 100% rename from src/list/raxos/quorum-majority-3.excalidraw.png rename to src/list/raxos/assets/quorum-majority-3.excalidraw.png diff --git a/src/list/raxos/quorum-nxn.excalidraw.png b/src/list/raxos/assets/quorum-nxn.excalidraw.png similarity index 100% rename from src/list/raxos/quorum-nxn.excalidraw.png rename to src/list/raxos/assets/quorum-nxn.excalidraw.png diff --git a/src/list/raxos/crdt.excalidraw.png b/src/list/raxos/crdt.excalidraw.png deleted file mode 100644 index b4df278..0000000 Binary files a/src/list/raxos/crdt.excalidraw.png and /dev/null differ diff --git a/src/list/raxos/def-API-read-write.md b/src/list/raxos/def-API-read-write.md index a358dd2..8e771d5 100644 --- a/src/list/raxos/def-API-read-write.md +++ b/src/list/raxos/def-API-read-write.md @@ -2,8 +2,10 @@ 这个由虚拟时间Time, 事件Event 和 History 的系统中, 读操作和写操作都定义为在一个指定时间上发生的行为: ```rust -fn read(t: Time) -> History({T}); -fn write(h: History({T})); +impl Node { + fn read(&self, t: Time) -> History({T}); + fn write(&mut self, h: History({T})); +} ``` 其中, `read` 读系统中t时刻的历史, 即它应该返回所有t时刻之前发生的Event, read返回的History的最大时刻可能小于参数中的t. diff --git a/src/list/raxos/def-Observable-History.md b/src/list/raxos/def-Observable-History.md index 387fad8..d816c40 100644 --- a/src/list/raxos/def-Observable-History.md +++ b/src/list/raxos/def-Observable-History.md @@ -1,18 +1,18 @@ **def-Observable** ## 对系统总是可见的 History -对于某个时刻`pt`, -对一个 History, 如果这个时刻的 `read_quorum_set` 中任意一个`read_quorum` 都能读到这个 History, -那么就认为这个 History 是 **在`pt`时刻可见** 的. +对于某个时刻`T`, +对一个 History, 如果这个时刻的 `read_quorum_set` 中每个`read_quorum` 都能读到这个 History, +那么就认为这个 History 是 **在`T`时刻可见** 的. 注意 **可见** 是跟系统的状态和 `read_quorum_set` 的定义相关的, -例如, 下图中对 `History = {E1, E2}`来说, +例如, 下图中对 `History = {E1->E2}`来说, 如果 `read_quorum_set` 是多数派读写的定义, 即 `{{1,2},{1,3},{2,3}}`, 那么它 **可见** 的: ![](history-visible-12.excalidraw.png) -但对 `History = {E1, E2, E3}`来说, +但对 `History = {E1->E2->E3}`来说, - 如果 `read_quorum_set` 仍然是多数派读写的定义, 即 `{{1,2},{1,3},{2,3}}`, 那么它不是 **可见** 的, 因为通过`{2,3}`读不到`History = {E1,E2,E3}`, - 但如果修改 `read_quorum_set` 为 `{{1,2},{1,3}}`, 那么即使系统状态不变, diff --git a/src/list/raxos/def-RW-Distributed.md b/src/list/raxos/def-RW-Distributed.md index bd5072c..6340823 100644 --- a/src/list/raxos/def-RW-Distributed.md +++ b/src/list/raxos/def-RW-Distributed.md @@ -2,7 +2,25 @@ # 分布式多副本中的读写 -写操作要写一个历史,即 `fn write(h: History({T}), nodes: Vec)`, 对每个节点的写的内容都一样 +分布式中的读和写都是基于我们单机的API读写来完成的 我们首先看分布式的写 分布式中的写真的比较简单 它只需要把一个要写的history 写到每一个节点上就行了 就像我们下面的代码所展示的那样 分布式里面的读相对会稍微复杂一点 你读的话也是从每个副本上读一个history过来 然后再通过这些读到的结果 然后返回给客户调用者一个结果 + +```rust +impl { + fn write(&self, h: History({T})) { + for node in self.get_write_quorum() { + node.write(h); + } + } +} +``` + + + + + + + +写操作要写一个历史,即 `fn write(h: History({T}), nodes: &[Node])`, 对每个节点的写的内容都一样 直观上, 分布式环境中的读写变成了对多个节点的读写: ```rust diff --git a/src/list/raxos/def-Read-Quorum-Set.md b/src/list/raxos/def-Read-Quorum-Set.md index d050571..ab0631e 100644 --- a/src/list/raxos/def-Read-Quorum-Set.md +++ b/src/list/raxos/def-Read-Quorum-Set.md @@ -1,16 +1,16 @@ ## Read Quorum Set 对每个系统, 不论是单机的还是分布式的, -都显式的或隐含的定义了合法的 `read()` 可用的 `node_set` 有哪些, 系统只有用这样的`node_set` 读的时候才能提供 TODO: +都显式的或隐含的定义了可用于 `read()` 的 `node_set` 有哪些, 系统只有用这样的`node_set` 读的时候才能提供某种保证, 使用其他node set读取到的结果不提供任何保证: - 例如单机系统, `read()` 可用的 `node_set` 就是唯一这个节点`{{1}}`, 显然用一个空的 `node_set` 去读是没意义的. - 一个简单 3 节点系统中, 如果不做任何限制, 那么`read()`可用的`node_set`是所有非空节点集合: `{{1}, {2}, {3}, {1,2}, {2,3}, {1,3}, {1,2,3}}` - 但注意这样一个系统中`read()`得到的结果一般是没有任何高可用保证的, 因为它暗示了写操作必须写到每一个 node 上才能被合法的读读到. + 但注意这样一个系统中`read()`得到的结果一般是没有任何高可用保证的, 因为它暗示了一个写操作必须写到每一个 node 上才能被合法的读读到. -- 一个多数派读写的 3 节点系统中(n=3, w=2, r=2), +- 一个 [多数派读写][] 的 3 节点系统中(n=3, w=2, r=2), `read()`可用的`node_set`是至少包含 2 节点的集合: `{{1,2}, {2,3}, {1,3}, {1,2,3}}`, 如果一个 read 操作使用的 `node_set` 是这个系统定义的用于读的`node_set`, @@ -18,7 +18,13 @@ 对于不合法的 read 操作, 系统对读取的结果不能提供任何保证(undefined behavior). -**def-Read-Quorum-Set** **def-Read-Quorum**: -在某个时刻`pt`, 可合法的用于`read()`的`node_set`的集合, 就是系统这个`pt`时刻的`read_quorum_set`, +**def-Read-Quorum-Set** +**def-Read-Quorum**: + +在某个时刻`T`, 可合法的用于`read()`的`node_set`的集合, 就是系统在这个`T`时刻的`read_quorum_set(T)`, 注意不同时间T的`read_quorum_set(T)`可能不同, 例如 [Raft][] 的配置变更时. + `read_quorum_set` 中的一个元素是一个节点集合, 称之为一个`read_quorum`. -`read_quorum` 是一个节点集合`node_set`, `read_quorum_set` 是一个 节点集合的集合. \ No newline at end of file + + +[多数派读写]: http://a +[Raft]: http://a \ No newline at end of file diff --git a/src/list/raxos/history-visible-12.excalidraw.png b/src/list/raxos/history-visible-12.excalidraw.png deleted file mode 100644 index fad9b63..0000000 Binary files a/src/list/raxos/history-visible-12.excalidraw.png and /dev/null differ diff --git a/src/list/raxos/raxos.md b/src/list/raxos/raxos.md index c16e517..dadd540 100644 --- a/src/list/raxos/raxos.md +++ b/src/list/raxos/raxos.md @@ -34,48 +34,7 @@ TODO: remove concept History quorum -## History Read Set - -对于 -`fn read(pt: PTime, nodes: Vec) -> History`, -对读到的 History 的任一子集 H, 我们可以称这个`node_set` 是这个`History`的一个 ReadSet. 表示这个`History` 可以通过这个`node_set`读到. - -对系统的某个特定的状态, Histroy 的 ReadSet 定义为可以读到这个 History 的一个节点的集合. - -例如, 在下面, - -- `read({1})` 返回: `[History{E1, E2, E3}]`, -- `read({1, 2})` 返回: `[History{E1, E2, E3}, History{E1, E2}]`, -- `read({3})` 返回空 `ø`. - -例如, 在下面这个 3 节点的系统中, `History{E1,E2,E3}`的 ReadSet, 即能读到它的节点的集合, 有 4 个, 是所有包括 node-1 节点的节点集合: - -`{1}, {1,2}, {1,2,3}, {1,3}` - -例如`read({1})` 会返回`History{E1,E2,E3}`在结果里, -`read({1,3})` 也会返回`History{E1,E2,E3}`在结果里. - -但是`read({3})` 不会返回`History{E1,E2,E3}`, 所以 `{3}` 不是`History{E1,E2,E3}` 的一个 ReadSet - -而`History{E1,E2}`的 ReadSet 有 5 个, 除了`{3}` 之外的所有非空节点集合都是它的 ReadSet: -`{1}, {1,2}, {1,2,3}, {1,3}, {2,3}`, - -例如`read({2,3})` 会返回`History{E1,E2}`在结果里. - -![](history-read-set.excalidraw.png) - -对于返回的结果, 我们也可以将 `Vec`里的元素做一个并集来简化表示, -例如, 上图中, `read({1, 2})` 可以看做返回了一个 History: `History{E1, E2, E3}` - -而在下图中, 我们可以认为`read({1, 2})` 返回了一个树形的 History: - -``` - .->E4 -E1->E2->E3 -``` - -![](history-read-set-union.excalidraw.png) - +[[desc-History Read Set]] [[def-Read-Quorum-Set]] @@ -237,6 +196,8 @@ node-1 本地将已有 History 跟新写入的 History 合并了, 本地存储 ![](linear-rw.excalidraw.png) +protocol-write-prepare + ## Write Prepare 现在 write 保证了不覆盖已有的 History, 且写到了`write_quorum_set`, @@ -305,30 +266,18 @@ node-1 本地将已有 History 跟新写入的 History 合并了, 本地存储 我举这个例子是为了说明, Time 的每个维度之间的类型不能假设是一样的, 即不支持加法, 但可以支持乘法. 这将会引出后面的有趣的结论. +[[example-crdt]] -# 多维偏序时间应用例子 +[[example-2d-non-transitive-time]] -假设有一个 key value 的存储系统，在这个系统里面，每个 key 都代表一个不同的维度。然后我们的时间，就是一个多维的向量时间内的比较，就是多为向量的比较。 -我们先从一个简单的场景来看, 假设这个系统里只有2个key: -x 和 y, -这个系统的虚拟时间`T`定义为: 一个操作涉及的key的对应的维度上值为i的向量. -例如, `let x = 2` 的T为`{x:i}`, -`let y = 3`的T为`{y:i}`; -`let x = x + y`的T为`{x:i, y:i}` -T的比较关系定义为公共分量的大小比较: -例如, `{x:1} < {x:2,y:2} < {y:3}`, 但`{x:1}` `{y:2}` 之间没有大小关系, 因为它们没有公共分量. -这个虚拟时间定义了哪些Event可以互补影响的执行, 哪些之间必须有确定的顺序, 以及这些顺序是什么(有`i` 定义). +[[exmaple-crdt-define]] +[[example-crdt-implementation]] -![](crdt.excalidraw.png) - -应用我们的Abstract Paxos到这个系统, 它将构建一个冲突自适应的Multi Master一致性协议. 例如 -注意, 我们时间是对应到DAG的结构的, `{x:2,y:2} < {y:3}` 中的 `{y:3}` 顶点和 一个独立的 `{y:3}` 顶点代表的不是一个时间. - 如果T不是**传递的**, 那么第一阶段必须在一个read-quorum-set上阻止要写入的History上所有的T, 而不是只有最大的一个T.因为不能通过T来防止之前的顶点被写入. 而在第二阶段, 也必须逐个判断要写入的History的每个T是否小于已经被阻止的T, 而不仅仅是要写入的History的Maximal T.