Elasticsearch集羣40億級優化

目前架構：

n臺filebeat客戶端來將每臺應用上的日誌傳到kafka，3臺kafka作集羣用於日誌隊列，四臺ES作集羣，前兩臺存放近兩天熱數據日誌，後兩臺存放兩天前的歷史日誌，數據保存一個月，目前總數據量44億，大小爲6T。logstash與kibana與ES在一臺機器上，kibana域名指向後端三個kibana作輪詢。

出現性能問題：

一、集羣中只有第一臺負載很高，其餘節點負載一直都很低，偶爾同爲hot數據節點的第二臺負載也會稍微有點升高。

二、隊列常常堵塞，kafka中uat,pet,prd三個環境的topic同在一個默認的logstash消費組。只要其中一個環境的列隊積壓，其餘環境的隊列就沒法消費了。

三、Kibana登錄後首頁打開，須要至少半分鐘，日誌查詢也很慢，至少幾分鐘纔會出結果。

四、有時候ES常因負載高而脫離集羣，致使集羣節點數據從新分配，集羣狀態顏色爲RED，同時kibana頁面打開時顯示Red報錯。kibana頁面間斷沒法打開的狀況約持續一兩週。

目前ELK中發現有些索引查詢有點慢，因而打開ES索引查詢日誌來記錄慢查詢，進而對慢查詢日誌進行分析，定位問題。慢日誌內容以下：

[2017-08-28T11:21:02,377][WARN ][index.search.slowlog.query] [node-3] [logstash-nginx-2017.08.01][4] took[15s], took_millis[15029], types[], stats[], search
_type[QUERY_THEN_FETCH], total_shards[140], source[{"size":0,"query":{"bool":{"filter":[{"match_none":{"boost":1.0}},{"query_string":{"query":"NOT status:200  OR  NOT
status:304","fields":[],"use_dis_max":true,"tie_breaker":0.0,"default_operator":"or","auto_generate_phrase_queries":false,"max_determined_states":10000,"enable_position
_increment":true,"fuzziness":"AUTO","fuzzy_prefix_length":0,"fuzzy_max_expansions":50,"phrase_slop":0,"analyze_wildcard":true,"escape":false,"split_on_whitespace":true,
"boost":1.0}}],"disable_coord":false,"adjust_pure_negative":true,"boost":1.0}},"aggregations":{"3":{"terms":{"field":"status","size":5,"min_doc_count":0,"shard_min_doc_
count":0,"show_term_doc_count_error":false,"order":[{"_count":"desc"},{"_term":"asc"}]},"aggregations":{"2":{"date_histogram":{"field":"@timestamp","format":"epoch_mill
is","interval":"20m","offset":0,"order":{"_key":"asc"},"keyed":false,"min_doc_count":0,"extended_bounds":{"min":"1503886846372","max":"1503890446372"}}}}}}}],
[2017-08-28T11:21:02,377][WARN ][index.search.slowlog.query] [node-3] [logstash-nginx-2017.08.01][2] took[15.7s], took_millis[15787], types[], stats[], sear
ch_type[QUERY_THEN_FETCH], total_shards[140], source[{"size":0,"query":{"bool":{"filter":[{"match_none":{"boost":1.0}},{"query_string":{"query":"NOT status:200  OR  NOT
  status:304","fields":[],"use_dis_max":true,"tie_breaker":0.0,"default_operator":"or","auto_generate_phrase_queries":false,"max_determined_states":10000,"enable_positi
on_increment":true,"fuzziness":"AUTO","fuzzy_prefix_length":0,"fuzzy_max_expansions":50,"phrase_slop":0,"analyze_wildcard":true,"escape":false,"split_on_whitespace":tru
e,"boost":1.0}}],"disable_coord":false,"adjust_pure_negative":true,"boost":1.0}},"aggregations":{"3":{"terms":{"field":"status","size":5,"min_doc_count":0,"shard_min_do
c_count":0,"show_term_doc_count_error":false,"order":[{"_count":"desc"},{"_term":"asc"}]},"aggregations":{"2":{"date_histogram":{"field":"@timestamp","format":"epoch_mi
llis","interval":"20m","offset":0,"order":{"_key":"asc"},"keyed":false,"min_doc_count":0,"extended_bounds":{"min":"1503886846372","max":"1503890446372"}}}}}}}],

下面進行分析：

待續