騰訊雲Elasticsearch集羣多可用區容災實現原理及最佳實踐

{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"引言"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"目前騰訊雲 ES 集羣可以支持雙可用區及三可用區的集羣部署，且支持單可用區平滑升級到多可用區集羣。當一個可用區出現故障時，剩餘可用區依然能夠保障集羣的穩定性、服務的可用性和數據的完整性。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"數據節點"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"當客戶選擇了跨多可用區的集羣架構部署時，集羣的數據節點必須是多可用區的倍數，如客戶選擇的是三可用區部署，則數據節點個數應爲 3，6，9，12 等，以此類推。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/58\/5808832f80f53a2ff1d2f491232321cf.png","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如上圖 1 所示，我們在上海地域選擇了三可用區集羣的部署，數據節點數量選擇 6 個。ES 會自動將 6 個數據節點均衡得分佈在三個可用區中，並對每個節點標記上可用區屬性，從而可以通過可用區感知功能將索引的分片自動分佈在多可用區中，集羣中節點的具體分佈情況如圖 2 所示。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/b0\/b00f72236ea1d5d7de599dfbfd502dcb.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"從圖 2 中我們可以看到，騰訊雲 ES 提供了 VPC 內的負載均衡功能，客戶可以直接通過 VIP 連接集羣，由於 VIP 下綁定了集羣內部的所有數據節點，因此客戶所有的讀寫請求會均衡的分佈到各個數據節點上。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"另外該 VIP 還自帶健康檢查功能，如一個週期內多次檢測到某節點未響應，健康檢查功能則會暫時從該 VIP 的路由列表中摘除該異常節點，直到節點恢復正常。這樣就保障了當一個節點宕機或者某一個可用區不可用的情況下，客戶端依然能夠無感知的請求集羣。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"專用主節點"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"爲了保障集羣的穩定性和高可用性，當選擇多可用區集羣架構部署時，需強制設置三個專用主節點。其中專用主節點的分佈機制如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"當選擇三可用區部署時，會在每個可用區部署一個專用主節點，從而保障任何一個可用區不可用時，依然能夠選出 Master 節點；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"當選擇雙可用區部署時，爲了避免出現一個可用區上分佈兩個專用主節點且出現“該可用區不可用”導致選不出 Master 節點的情況，騰訊雲 ES 會選擇一個隱藏可用區用來專門部署專用主節點，如下圖 3 所示。"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/e1\/e179af8753570f6eac0778ca3f167a5c.png","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"索引副本分片"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"爲了保障在一個可用區不可用的情況下，依然能夠保證數據的完整性和服務的可用性，索引分片至少設置 1 副本。如果選擇三可用區部署，當兩個可用區不可用時，希望剩下的可用區依然能夠完整提供服務，則索引的副本個數至少爲 2 個。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"ES多可用區架構部署實現機制"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"騰訊雲 ES 多可用區集羣部署依賴於 ES 提供的節點屬性感知 "},{"type":"text","marks":[{"type":"italic"},{"type":"underline"}],"text":"awareness [1]"},{"type":"text","marks":[{"type":"italic"}],"text":" "},{"type":"text","text":"功能。通過對每個節點進行屬性標記，即對節點進行可用區的屬性標記:\"node.attr.zone_id:shanghai-3\"。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"該屬性配置在 elasticsearch.yml 文件中(也可以選擇在啓動節點時進行參數指定：\".\/bin\/elasticsearch -Enode.attr.zone_id=shanghai-3\")，設置完節點屬性後，騰訊雲 ES 集羣通過設置如下參數：\"cluster.routing.allocation.awareness.attributes=zone_id\" 來讓集羣在分片分配中使用節點屬性執行分配策略。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"這樣 ES 就可以通過可用區 zone_id 屬性將節點進行分類。且將索引的主副本分片分佈到屬性 zone_id 不同的節點上。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"例如，我們創建了一個具有 4 個數據節點的雙可用區的集羣，分別部署在上海 3 區和上海 4 區。那麼上海 3 區的節點屬性爲: \"node.attr.zone_id:shanghai-3\"，上海 4 區的節點屬性爲: \"node.attr.zone_id:shanghai-4\"。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"當我們創建一個索引，該索引有 5 個主分片和 1 個副本分片，那麼所有的主分片和對應的副本分片都會均衡的分佈在上海 3 區和 4 區上，而不會出現主分片和副本分片同時分佈在上海 3 區或者上海 4 區的情況。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"需要注意的是：這時候如果有一個可用區掛掉，如上海 3 區整體不可用，ES 會將上海 3 區的主副本分片在上海 4 區進行重建。即這時候會出現主副本分片同時分配在同一個可用區的情況。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"爲了防止某一個可用區不可用，導致另一個可用區磁盤容量被重建的分片大量耗盡的情況，騰訊雲 ES 啓用了分片強制感知 (force awareness) 的功能。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"騰訊雲 ES 通知設置如下參數：cluster.routing.allocation.awareness.force.zone_id.values=shanghai-3,shanghai-4，從而保證了在一個可用區不可用時，不會使得剩餘的可用區磁盤資源不足的情況。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"單可用區平滑升級多可用區"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"前文圖 1 演示了在騰訊雲 ES 控制檯購買多可用區集羣的操作步驟。對於存量的單可用區集羣，騰訊雲 ES 同樣支持平滑升級到多可用區的部署架構。具體操作如下圖 4 所示："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/c3\/c3be278cb8bc1014902a73667952e343.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"這裏需要注意以下幾點："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"當選擇了升級到多可用區時，只能設置新的可用區信息，不可更改節點配置和磁盤容量；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"當升級到雙可用區時，數據節點數量自動翻倍；當升級到三可用區時，數據節點數量自動乘三倍；當從雙可用區升級到三可用區時，數據節點數量自動乘 1.5 倍；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如果原集羣未設置專用主節點，則會強制選擇設置 3 個專用主節點；如果原集羣設置了專用主節點，則節點數量不變，騰訊雲 ES 會自動完成專用主節點在各可用區之間的調度和分佈。"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"單可用區升級到多可用區的變配流程最大的難點和挑戰在於專用主節點的協調上。下面重點介紹騰訊雲 ES 在處理可用區升級方案中專用主節點的實現機制："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"爲了下圖說明方便，我們先對各類型節點使用不同顏色進行標記："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/24\/24b91a3f10313efa9d8aa3ca50dd656a.png","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"普通節點：包含 master、data、ingest 等所有屬性，節點上存儲索引數據，使用藍色標記。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/b2\/b218be00ce278d618aabd19763cac66a.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"專用主節點：只包含 master 屬性，在集羣中屬於專用主節點，不存儲索引數據，只負責管理集羣和存儲集羣的元數據信息，使用粉紅色標記。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/71\/71bf915e6d519b74b6128cc592fa931f.png","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"數據節點：只包含 data、ingest 屬性，一般用於具有專用主節點的場景，該節點上存儲索引數據，通常也被稱爲專有數據節點，使用綠色標記。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"單可用區升級到多可用區場景分析："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"（1）原單可用區集羣沒有專用主節點："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如果原單可用區集羣沒有設置專用主節點，這種情況下無論是升級到雙可用區還是三可用區都是比較簡單的。"}]},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/ba\/ba2d8decfba7b13c5406062148de373d.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"升級變配流程如上圖 5 所示："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在新增的可用區中申請創建並加入普通節點以及在每個可用區中各加入一個專用主節點（如果是升級到雙可用區，則會在隱藏可用區加入一個專用主節點）；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"修改各可用區中普通節點的屬性爲專有數據節點，即上圖中將藍色變更爲綠色。"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在流程的第 2 步修改節點屬性時，每重啓一個節點，min_master_node 都會重新計算並設定，避免在中間狀態發生腦裂。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"（2）原單可用區集羣已設置專用主節點："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如果原單可用區集羣中已經設置了 3 個專用主節點，那麼按照最終的狀態來看，應該是每個可用區都會均衡分佈一個專用主節點。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"自然想到的流程是先在新增的可用區中各加入一個專用主節點，然後再將原可用區中的多餘兩個專用主節點下線即可。如下圖 6 所示："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/67\/6743aaeec10d7471b821deb6b1fd188b.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"具體流程步驟如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在新增的可用區中加入數據節點及一個專用主節點（如果是升級到雙可用區，則只需要在隱藏可用區申請加入一個專用主節點即可）；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"將原單可用區中多出的兩個專用主節點下線。"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"但是這種升級變配流程存在一個隱藏的集羣不可用風險。如圖 7 所示："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/21\/21870dc3826cb84035feb5e12c114849.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"從圖 6 的第一個流程上我們再結合圖 7 可以看到，如果在中間狀態原單可用區突然發生不可用，那便會出現剩餘的可用區中只剩下 2 個專用主節點，這時候從 5 個專主變成了 2 個專用主節點，便會出現選不出 Master 節點的情況，從而使得集羣整體不可用，違背了跨可用區的容災初衷。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"爲了規避上面分析的這種異常風險，我們對圖 6 的第 1 個流程的中間狀態做了優化，如下圖 8 所示："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https:\/\/static001.geekbang.org\/infoq\/b5\/b5b4a4f96e264eeea29c8729c95e9187.webp","alt":"Image","title":null,"style":[{"key":"width","value":"75%"},{"key":"bordertype","value":"none"}],"href":null,"fromPaste":true,"pastePass":true}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"具體流程如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在新增的可用區中加入數據節點及兩個專用主節點（如果是升級到雙可用區，則只需要在隱藏可用區申請加入兩個專用主節點即可）；"}]}]},{"type":"listitem","attrs":{"listStyle":null},"content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"將原單可用區中多出的兩個專用主節點和新增的可用區中多出的一個專用主節點下線。"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"這樣便可保證即使在流程一的中間狀態下任何一個可用區不可用，依然不影響剩餘專用主節點選出 Master 節點。從而保障了集羣的高可用性。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"結語"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":"br"}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"本篇文章我們詳細介紹和分析了騰訊雲 ES 集羣多可用區容災的實現原理和操作實踐。並重點介紹了單可用區集羣升級到多可用區的幾種場景及具體流程細節，希望能夠幫助到騰訊雲 ES 的客戶朋友們。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"horizontalrule"},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"頭圖：Unsplash"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"作者：吳容"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"原文：https:\/\/mp.weixin.qq.com\/s\/7VzmoK4ZsVfnJflEs_B9tA"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"原文：騰訊雲Elasticsearch集羣多可用區容災實現原理及最佳實踐"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"來源：雲加社區 - 微信公衆號 [ID：QcloudCommunity]"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"轉載：著作權歸作者所有。商業轉載請聯繫作者獲得授權，非商業轉載請註明出處。"}]}]}