简介：
Squid 服务器日志增长是很快的，如果不做处理的话，可以会由于系统限制单文件大小，而导致 Squid 服务停止，太大的日志文件也不适合分析。
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
## 这是 squid.conf 中关于 log 的配置项，分别定义了三个日志文件 access.log cache.log store.log
## logfile_rotate 7 代表保留 6 个历史日志文件，跟 1 个当前日志文件
## 默认 Squid 是不作日志切割的，系统允许写多大，那么日志文件就写多大
shell > squid -k rotate
## 使用 squid -k rotate 来切割日志，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
## 使用任务计划来定期切割日志
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
## 由于参数 logfile_rotate 7 的限定，每个日志文件最多保存 7 个（ 自动删除 ）
二、日志分析
/var/log/squid/access.log ## 时间戳 默认以 UTC 1970-01-01 00:00:00 到现在的秒数表示，显示为毫秒 响应时间 处理所用时间，毫秒 客户端地址 客户端 IP 地址 结果码/状态码 结果码表示 Squid 专有的编码，如 TCP_HIT 、UDP_DENIED 等，状态码是 HTTP 的响应代码，如 200、301、404、503 等 传输 Size 给客户端传输字节数 请求方式 HTTP 或 ICP 两种，HTTP 一般为 GET ，ICP 一般为 ICP_QUERY URL 请求的 URL 地址 客户端身份 对端编码/对端主机 内容类型 HTTP 响应的内容类型 HTTP 请求头部 HTTP 响应头部 ## access.log 结果码（ 部分常见的，更多请常找相关资料 ） TCP_HIT ## 在硬盘中发现有效请求资源并立即回传给用户的数据 TCP_MISS ## 没有被缓存，并回传给用户的数据 TCP_MEM_HIT ## 在内存中发现有效的请求资源并立即回传给用户的数据 TCP_REFRESH_UNMODIFIED ## 请求资源可能是旧的缓存，发送确认请求到原始服务器，原始服务器返回 304 未修改响应，指示 Squid 的缓存是最新的。并回传给用户的数据 TCP_REFRESH_MODIFIED ## 请求资源可能是旧的缓存，发送确认请求到原始服务器，原始服务器返回新的数据，指示这个缓存是旧的，缓存并回传给用户的数据 shell > cat /var/log/squid/access.log | grep TCP_HIT ## 被缓存到硬盘并回传给用户的数据 shell > cat /var/log/squid/access.log | grep TCP_MEM_HIT ## 被缓存到内存并回传给用户的数据 shell > cat /var/log/squid/access.log | grep TCP_MISS ## 没有被缓存的数据，而是从原始服务器获取并回传给用户的数据
三、缓存命中率
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% ## 请求命中率 5分内平均 0.0% ,60分内平均 86.0% Hits as % of bytes sent: 5min: 100.0%, 60min: 99.1% ## 字节命中率 Memory hits as % of hit requests: 5min: 0.0%, 60min: 0.0% ## 内存命中率 Disk hits as % of hit requests: 5min: 0.0%, 60min: 13.5% ## 磁盘命中率 Storage Swap size: 31228 KB ## 缓存目录大小 Storage Swap capacity: 0.7% used, 99.3% free Storage Mem size: 108 KB ## 缓存内存大小 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