一、簡 介
Loki是受Prometheus啟發由Grafana Labs團隊開源的水平可擴充套件，高度可用的多租戶日誌聚合系統。 開發語言: Google Go。它的設計具有很高的成本效益，並且易於操作。使用標籤來作為索引，而不是對全文進行檢索，也就是說，你透過這些標籤既可以查詢日誌的內容也可以查詢到監控的資料籤，極大地降低了日誌索引的儲存。系統架構十分簡單，由以下3個部分組成 ：
Promtail 是代理，負責收集日誌並將其傳送給 loki 。
Loki 是主伺服器，負責儲存日誌和處理查詢 。
Grafana 用於 UI 展示。
只要在應用程式伺服器上安裝promtail來收集日誌然後傳送給Loki儲存，就可以在Grafana UI介面透過新增Loki為資料來源進行日誌查詢（如果Loki伺服器效能不夠，可以部署多個Loki進行儲存及查詢）。作為一個日誌系統不光只有查詢分析日誌的能力，還能對日誌進行監控和報警。
二、原理分析
promtail收集並將日誌傳送給loki的 Distributor 元件 Distributor會對接收到的日誌流進行正確性校驗，並將驗證後的日誌分批並行傳送到Ingester Ingester 接受日誌流並構建資料塊，壓縮後存放到所連線的儲存後端 Querier 收到HTTP查詢請求，並將請求傳送至Ingester 用以獲取記憶體資料 ，Ingester 收到請求後返回符合條件的資料 ； 如果 Ingester 沒有返回資料，Querier 會從後端儲存載入資料並遍歷去重執行查詢 ，透過HTTP返回查詢結果
三、對比
PLG與ELK比較優勢ELK雖然功能豐富，但規模複雜，資源佔用高，操作苦難，很多功能往往用不上，有點殺雞用牛刀的感覺。 Loki 不對日誌進行全文索引。透過儲存壓縮非結構化日誌和索引後設資料，Loki 操作起來會更簡單，更省成本。 透過使用與 Prometheus 相同的標籤記錄流對日誌進行索引和分組，這使得日誌的擴充套件和操作效率更高。 安裝部署簡單快速，且受 Grafana 原生支援。
四、下載
curl -O -L "https://github.com/grafana/loki/releases/download/v1.5.0/loki-linux-amd64.zip" curl -O -L "https://github.com/grafana/loki/releases/download/v1.5.0/promtail-linux-amd64.zip" wget https://dl.grafana.com/enterprise/release/grafana-enterprise-8.3.3.linux-amd64.tar.gz
五、 安裝loki、grafana、promtail
安裝loki
先將loki-linux-amd64.zip和grafana-enterprise-8.3.3.linux-amd64.tar.gz上傳到日誌伺服器（10.60.134.55）；再將promtail-linux-amd64.zip上傳到應用伺服器（10.60.134.60、10.60.134.48、10.60.134.56）。
在日誌伺服器 上建立目錄 /usr/local/logsCollect/loki用於安裝loki，建立目錄/usr/local/logsCollect/grafana用於安裝grafana，如下：
mkdir /data/loki mkdir /data/loki/{chunks,index}
在日誌伺服器 上建立目錄，用於檔案儲存和索引儲存。
解壓unzip loki-linux-amd64.zip，並配置config.yaml
auth_enabled: false server: http_listen_port: 8094 ingester: lifecycler: address: 10.60.134.55 #日誌伺服器ip，即本機地址 ring: kvstore: store: inmemory replication_factor: 1 final_sleep: 0s chunk_idle_period: 5m chunk_retain_period: 30s schema_config: configs: - from: 2024-04-01 store: boltdb object_store: filesystem schema: v11 index: prefix: index_ period: 168h #每張表的時間範圍7天 storage_config: boltdb: directory: /data/loki/index #索引檔案儲存地址 filesystem: directory: /data/loki/chunks #塊儲存地址 limits_config: enforce_metric_name: false reject_old_samples: true reject_old_samples_max_age: 168h chunk_store_config: # 最大可查詢歷史日期 7天,這個時間必須是schema_config中的period的倍數，否則報錯。 max_look_back_period: 168h # 表的保留期7天 table_manager: retention_deletes_enabled: true retention_period: 168h
並建立啟動指令碼start.sh和關閉指令碼shutdown.sh
#!/bin/bash nohup ./loki-linux-amd64 -config.file=./config.yaml >./server.log 2>&1 & echo "$!" > pid
#!/bin/bash kill -9 `cat pid` echo "關閉成功!"
啟動loki命令：sh start.sh。如下日誌表示啟動成功。
安裝 grafana
首先解壓grafana-enterprise-8.3.3.linux-amd64.tar.gz，建立啟動指令碼start.sh和關閉指令碼shutdown.sh。注意conf/defaults.ini為grafana的配置檔案，其中http_port為瀏覽器訪問埠。
啟動grafana命令：sh start.sh。如下日誌表示啟動成功。
在應用伺服器安裝 promtail
在應用伺服器 上建立目錄 /usr/local/logsCollect/promtail用於安裝promtail。
解壓promtail-linux-amd64.zip，並配置promtail.yaml
server: http_listen_port: 9080 grpc_listen_port: 0 positions: filename: ./positions.yaml clients: - url: http://10.60.134.55:8094/loki/api/v1/push #日誌伺服器loki地址和埠 scrape_configs: #ucenter1 - job_name: zcbackend-172.29.21.22-1 static_configs: - targets: - 10.60.134.60 - labels: job: zcbachend-172.29.21.22-1 host: 10.60.134.60 __path__: /jiuqi/zichan/zichanyitihuazhenghexiangmu-8084/backend/server.log #本機日誌路徑
並建立啟動指令碼start.sh和關閉指令碼shutdown.sh
啟動promtail命令：sh start.sh。如下日誌表示啟動成功。
六、 測試
開啟grafana。預設密碼admin/admin。
新增資料來源
測試連線
查詢日誌
也能透過匯入的方式新增皮膚，json檔案如下：
{
"annotations": {
"list": [
{
"builtIn": 1,
"datasource": {
"type": "datasource",
"uid": "grafana"
},
"enable": true,
"hide": true,
"iconColor": "rgba(0, 211, 255, 1)",
"name": "Annotations & Alerts",
"target": {
"limit": 100,
"matchAny": false,
"tags": [],
"type": "dashboard"
},
"type": "dashboard"
}
]
},
"editable": true,
"fiscalYearStartMonth": 0,
"graphTooltip": 0,
"id": 3,
"iteration": 1671275851848,
"links": [],
"liveNow": false,
"panels": [
{
"aliasColors": {},
"bars": false,
"dashLength": 10,
"dashes": false,
"datasource": {
"type": "loki",
"uid": "${ENV}"
},
"fill": 1,
"fillGradient": 0,
"gridPos": {
"h": 5,
"w": 24,
"x": 0,
"y": 0
},
"hiddenSeries": false,
"id": 4,
"legend": {
"alignAsTable": true,
"avg": false,
"current": false,
"max": false,
"min": false,
"rightSide": true,
"show": true,
"total": false,
"values": false
},
"lines": true,
"linewidth": 1,
"nullPointMode": "null",
"options": {
"alertThreshold": true
},
"percentage": false,
"pluginVersion": "8.5.10",
"pointradius": 2,
"points": false,
"renderer": "flot",
"seriesOverrides": [],
"spaceLength": 10,
"stack": false,
"steppedLine": false,
"targets": [
{
"datasource": {
"type": "loki",
"uid": "hJ7iGN-Sz"
},
"expr": "sum (count_over_time({filename=~\"$log\",host=~\"$host\"}[2m] )) by (host,filename)",
"hide": false,
"legendFormat": "{{host}}=={{filename}}",
"refId": "B"
}
],
"thresholds": [],
"timeRegions": [],
"title": "日誌量統計",
"tooltip": {
"shared": true,
"sort": 0,
"value_type": "individual"
},
"type": "graph",
"xaxis": {
"mode": "time",
"show": true,
"values": []
},
"yaxes": [
{
"$$hashKey": "object:319",
"format": "short",
"logBase": 1,
"show": true
},
{
"$$hashKey": "object:320",
"format": "short",
"logBase": 1,
"show": true
}
],
"yaxis": {
"align": false
}
},
{
"datasource": {
"type": "loki",
"uid": "hJ7iGN-Sz"
},
"description": "",
"gridPos": {
"h": 21,
"w": 24,
"x": 0,
"y": 5
},
"id": 2,
"options": {
"dedupStrategy": "exact",
"enableLogDetails": false,
"prettifyLogMessage": false,
"showCommonLabels": false,
"showLabels": false,
"showTime": true,
"sortOrder": "Descending",
"wrapLogMessage": true
},
"pluginVersion": "7.4.3",
"targets": [
{
"datasource": {
"type": "loki",
"uid": "hJ7iGN-Sz"
},
"expr": "{filename=~\"$log\",host=~\"$host\"}|~ \"(?i)$log_level\"",
"hide": false,
"maxLines": 500,
"refId": "C"
}
],
"title": "日誌",
"transparent": true,
"type": "logs"
}
],
"refresh": "",
"schemaVersion": 36,
"style": "dark",
"tags": [
"PLG"
],
"templating": {
"list": [
{
"current": {
"selected": false,
"text": "Loki",
"value": "Loki"
},
"hide": 0,
"includeAll": false,
"label": "選擇環境",
"multi": false,
"name": "ENV",
"options": [],
"query": "loki",
"queryValue": "",
"refresh": 1,
"regex": "",
"skipUrlSync": false,
"type": "datasource"
},
{
"current": {
"selected": true,
"text": "資產server",
"value": "資產server"
},
"datasource": {
"type": "loki",
"uid": "hJ7iGN-Sz"
},
"definition": "label_values({},filename)",
"hide": 0,
"includeAll": false,
"label": "日誌",
"multi": false,
"name": "log",
"options": [
{
"selected": true,
"text": "資產server-8084",
"value": "/jiuqi/zichan/zichanyitihuazhenghexiangmu-8084/backend/server.log"
},
{
"selected": true,
"text": "資產server-8085",
"value": "/jiuqi/zichan/zichanyitihuazhenghexiangmu-8085/backend/server.log"
},
{
"selected": true,
"text": "資產server-8086",
"value": "/jiuqi/zichan/zichanyitihuazhenghexiangmu-8086/backend/server.log"
},
{
"selected": true,
"text": "公車server-8087",
"value": "/jiuqi/gongche/yitihuagongchehouduan-8087/backend/server.log"
},
{
"selected": true,
"text": "公車server-8088",
"value": "/jiuqi/gongche/yitihuagongchehouduan-8088/backend/server.log"
}
],
"query": "label_values({},filename)",
"refresh": 1,
"regex": "",
"skipUrlSync": false,
"sort": 1,
"type": "query"
},
{
"current": {
"selected": true,
"text": "172.29.21.22",
"value": "10.60.134.60"
},
"datasource": {
"type": "loki",
"uid": "hJ7iGN-Sz"
},
"definition": "label_values({},host)",
"hide": 0,
"includeAll": false,
"label": "主機IP",
"multi": false,
"name": "host",
"options": [
{
"selected": true,
"text": "資產-172.29.21.22",
"value": "10.60.134.60"
},
{
"selected": true,
"text": "資產-172.29.21.164",
"value": "10.60.134.48"
},
{
"selected": true,
"text": "公車-172.29.21.36",
"value": "10.60.134.56"
}
],
"query": "label_values({},host)",
"refresh": 1,
"regex": "",
"skipUrlSync": false,
"sort": 1,
"type": "query"
},
{
"allValue": "(^\\\\S|^\\\\s)",
"current": {
"selected": false,
"text": "All",
"value": "$__all"
},
"description": "可以直接輸入搜尋的關鍵字進行過濾",
"hide": 0,
"includeAll": true,
"label": "關鍵字過濾",
"multi": false,
"name": "log_level",
"options": [
{
"selected": true,
"text": "All",
"value": "$__all"
},
{
"selected": false,
"text": "INFO",
"value": "INFO"
},
{
"selected": false,
"text": "DEBUG",
"value": "DEBUG"
},
{
"selected": false,
"text": "WARN",
"value": "WARN"
},
{
"selected": false,
"text": "ERROR",
"value": "ERROR"
},
{
"selected": false,
"text": "UNKNOWN",
"value": "UNKNOWN"
},
{
"selected": false,
"text": "直接輸入關鍵字搜尋",
"value": "直接輸入關鍵字搜尋"
}
],
"query": "INFO,DEBUG,WARN,ERROR,UNKNOWN,直接輸入關鍵字搜尋",
"queryValue": "",
"skipUrlSync": false,
"type": "custom"
}
]
},
"time": {
"from": "now-1h",
"to": "now"
},
"timepicker": {},
"timezone": "",
"title": "Loki日誌收集",
"uid": "NlV_8QD7k",
"version": 19,
"weekStart": ""
}
