簡介：
Squid 服務器日志增長是很快的，如果不做處理的話，可以會由於系統限制單文件大小，而導致 Squid 服務停止，太大的日志文件也不適合分析。
一、日志配置
shell > grep 'log' /etc/squid/squid.conf cache_access_log /var/log/squid/access.log cache_log /var/log/squid/cache.log cache_store_log /var/log/squid/store.log logfile_rotate 7
## 這是 squid.conf 中關於 log 的配置項，分別定義了三個日志文件 access.log cache.log store.log
## logfile_rotate 7 代表保留 6 個歷史日志文件，跟 1 個當前日志文件
## 默認 Squid 是不作日志切割的，系統允許寫多大，那么日志文件就寫多大
shell > squid -k rotate
## 使用 squid -k rotate 來切割日志，切割的日志名按 .0 .1 .2 .3 .... 保存
shell > ls /var/log/squid/*.log* /var/log/squid/access.log /var/log/squid/cache.log /var/log/squid/store.log /var/log/squid/access.log.0 /var/log/squid/cache.log.0 /var/log/squid/store.log.0 shell > crontab -e 0 3 * * * /usr/sbin/squid -k rotate
## 使用任務計划來定期切割日志
shell > ls /var/log/squid/access.log* /var/log/squid/access.log /var/log/squid/access.log.1 /var/log/squid/access.log.3 /var/log/squid/access.log.5 /var/log/squid/access.log.0 /var/log/squid/access.log.2 /var/log/squid/access.log.4 /var/log/squid/access.log.6
shell > ls /var/log/squid/cache.log* /var/log/squid/cache.log /var/log/squid/cache.log.1 /var/log/squid/cache.log.3 /var/log/squid/cache.log.5 /var/log/squid/cache.log.0 /var/log/squid/cache.log.2 /var/log/squid/cache.log.4 /var/log/squid/cache.log.6
shell > ls /var/log/squid/store.log* /var/log/squid/store.log /var/log/squid/store.log.1 /var/log/squid/store.log.3 /var/log/squid/store.log.5 /var/log/squid/store.log.0 /var/log/squid/store.log.2 /var/log/squid/store.log.4 /var/log/squid/store.log.6
## 由於參數 logfile_rotate 7 的限定，每個日志文件最多保存 7 個（ 自動刪除 ）
二、日志分析
/var/log/squid/access.log ## 時間戳 默認以 UTC 1970-01-01 00:00:00 到現在的秒數表示，顯示為毫秒 響應時間 處理所用時間，毫秒 客戶端地址 客戶端 IP 地址 結果碼/狀態碼 結果碼表示 Squid 專有的編碼，如 TCP_HIT 、UDP_DENIED 等，狀態碼是 HTTP 的響應代碼，如 200、301、404、503 等 傳輸 Size 給客戶端傳輸字節數 請求方式 HTTP 或 ICP 兩種，HTTP 一般為 GET ，ICP 一般為 ICP_QUERY URL 請求的 URL 地址 客戶端身份 對端編碼/對端主機 內容類型 HTTP 響應的內容類型 HTTP 請求頭部 HTTP 響應頭部 ## access.log 結果碼（ 部分常見的，更多請常找相關資料 ） TCP_HIT ## 在硬盤中發現有效請求資源並立即回傳給用戶的數據 TCP_MISS ## 沒有被緩存，並回傳給用戶的數據 TCP_MEM_HIT ## 在內存中發現有效的請求資源並立即回傳給用戶的數據 TCP_REFRESH_UNMODIFIED ## 請求資源可能是舊的緩存，發送確認請求到原始服務器，原始服務器返回 304 未修改響應，指示 Squid 的緩存是最新的。並回傳給用戶的數據 TCP_REFRESH_MODIFIED ## 請求資源可能是舊的緩存，發送確認請求到原始服務器，原始服務器返回新的數據，指示這個緩存是舊的，緩存並回傳給用戶的數據 shell > cat /var/log/squid/access.log | grep TCP_HIT ## 被緩存到硬盤並回傳給用戶的數據 shell > cat /var/log/squid/access.log | grep TCP_MEM_HIT ## 被緩存到內存並回傳給用戶的數據 shell > cat /var/log/squid/access.log | grep TCP_MISS ## 沒有被緩存的數據，而是從原始服務器獲取並回傳給用戶的數據
三、緩存命中率
shell > squidclient -h 192.168.1.88 -p 80 mgr:info HTTP/1.0 200 OK Server: squid/3.1.10 Mime-Version: 1.0 Date: Wed, 07 Jan 2015 08:09:10 GMT Content-Type: text/plain Expires: Wed, 07 Jan 2015 08:09:10 GMT Last-Modified: Wed, 07 Jan 2015 08:09:10 GMT X-Cache: MISS from study.localhost.localdomain X-Cache-Lookup: MISS from study.localhost.localdomain:80 Via: 1.0 study.localhost.localdomain (squid/3.1.10) Connection: close Squid Object Cache: Version 3.1.10 Start Time: Wed, 07 Jan 2015 07:03:04 GMT Current Time: Wed, 07 Jan 2015 08:09:10 GMT Connection information for squid: Number of clients accessing cache: 2 Number of HTTP requests received: 741 Number of ICP messages received: 0 Number of ICP messages sent: 0 Number of queued ICP replies: 0 Number of HTCP messages received: 0 Number of HTCP messages sent: 0 Request failure ratio: 0.00 Average HTTP requests per minute since start: 11.2 Average ICP messages per minute since start: 0.0 Select loop called: 36984 times, 107.235 ms avg Cache information for squid: Hits as % of all requests: 5min: 0.0%, 60min: 86.0% ## 請求命中率 5分內平均 0.0% ,60分內平均 86.0% Hits as % of bytes sent: 5min: 100.0%, 60min: 99.1% ## 字節命中率 Memory hits as % of hit requests: 5min: 0.0%, 60min: 0.0% ## 內存命中率 Disk hits as % of hit requests: 5min: 0.0%, 60min: 13.5% ## 磁盤命中率 Storage Swap size: 31228 KB ## 緩存目錄大小 Storage Swap capacity: 0.7% used, 99.3% free Storage Mem size: 108 KB ## 緩存內存大小 Storage Mem capacity: 0.0% used, 100.0% free Mean Object Size: 255.97 KB Requests given to unlinkd: 0 Median Service Times (seconds) 5 min 60 min: HTTP Requests (All): 0.00000 0.00463 Cache Misses: 0.00000 0.04277 Cache Hits: 0.00000 0.08265 Near Hits: 0.00000 0.00286 Not-Modified Replies: 0.00000 0.00000 DNS Lookups: 0.00000 0.00000 ICP Queries: 0.00000 0.00000 Resource usage for squid: UP Time: 3965.980 seconds CPU Time: 4.601 seconds CPU Usage: 0.12% CPU Usage, 5 minute avg: 0.02% CPU Usage, 60 minute avg: 0.12% Process Data Segment Size via sbrk(): 3692 KB Maximum Resident Size: 79968 KB Page faults with physical i/o: 1 Memory accounted for: Total accounted: 474 KB 1% memPool accounted: 474 KB 1% memPool unaccounted: 38133 KB 99% memPoolAlloc calls: 225264 memPoolFree calls: 228120 File descriptor usage for squid: Maximum number of file descriptors: 65535 Largest file desc currently in use: 17 Number of file desc currently in use: 10 Files queued for open: 0 Available number of file descriptors: 65525 Reserved number of file descriptors: 100 Store Disk files open: 0 Internal Data Structures: 149 StoreEntries 27 StoreEntries with MemObjects 26 Hot Object Cache Items 122 on-disk objects