最近公司准备自建CDN，准备在原来的一台squid的基础上，再增加两台。由于长时间不动squid，对squid的配置和查看都生疏了。所以先拿自己的域名开刀，配置下squid，并查看下命中率。

 1[root@localhost squid]# squidclient -p 80 mgr:info
 2HTTP/1.0 200 OK
 3Server: squid/3.1.10
 4Mime-Version: 1.0
 5Date: Mon, 26 Nov 2012 14:41:51 GMT
 6Content-Type: text/plain
 7Expires: Mon, 26 Nov 2012 14:41:51 GMT
 8Last-Modified: Mon, 26 Nov 2012 14:41:51 GMT
 9X-Cache: MISS from cache.361way.com
10X-Cache-Lookup: MISS from cache.361way.com:80
11Via: 1.0 cache.361way.com (squid/3.1.10)
12Connection: close
13Squid Object Cache: Version 3.1.10
14Start Time:     Mon, 26 Nov 2012 13:18:50 GMT
15Current Time:   Mon, 26 Nov 2012 14:41:51 GMT
16Connection information for squid:
17        Number of clients accessing cache:      34
18        Number of HTTP requests received:       774
19        Number of ICP messages received:        0
20        Number of ICP messages sent:    0
21        Number of queued ICP replies:   0
22        Number of HTCP messages received:       0
23        Number of HTCP messages sent:   0
24        Request failure ratio:   0.00
25        Average HTTP requests per minute since start:   9.3   #每分钟http request的数量
26        Average ICP messages per minute since start:    0.0
27        Select loop called: 637052 times, 7.818 ms avg
28Cache information for squid:
29        Hits as % of all requests:      5min: 77.1%, 60min: 58.8%   #Cache Request命中率
30        Hits as % of bytes sent:        5min: 28.4%, 60min: 20.4%   #Cache Byte命中率
31        Memory hits as % of hit requests:       5min: 43.9%, 60min: 32.0%
32        Disk hits as % of hit requests: 5min: 0.0%, 60min: 0.2%
33        Storage Swap size:      328 KB  #存放cache的硬盘使用大小
34        Storage Swap capacity:   0.0% used, 100.0% free
35        Storage Mem size:       436 KB   #存放cache的内存使用大小
36        Storage Mem capacity:    0.1% used, 99.9% free
37        Mean Object Size:       6.56 KB
38        Requests given to unlinkd:      2
39Median Service Times (seconds)  5 min    60 min:
40        HTTP Requests (All):   0.06286  0.06286
41        Cache Misses:          0.32154  0.20843
42        Cache Hits:            0.00000  0.00000
43        Near Hits:             0.06286  0.06286
44        Not-Modified Replies:  0.00000  0.00000
45        DNS Lookups:           0.00000  0.00000
46        ICP Queries:           0.00000  0.00000
47Resource usage for squid:
48        UP Time:        4980.301 seconds
49        CPU Time:       1.379 seconds
50        CPU Usage:      0.03%
51        CPU Usage, 5 minute avg:        0.09%
52        CPU Usage, 60 minute avg:       0.03%
53        Process Data Segment Size via sbrk(): 7508 KB
54        Maximum Resident Size: 59728 KB
55        Page faults with physical i/o: 0
56Memory usage for squid via mallinfo():
57        Total space in arena:    7640 KB
58        Ordinary blocks:         7587 KB     61 blks
59        Small blocks:               0 KB      0 blks
60        Holding blocks:          1228 KB      5 blks
61        Free Small blocks:          0 KB
62        Free Ordinary blocks:      52 KB
63        Total in use:            8815 KB 99%
64        Total free:                52 KB 1%
65        Total size:              8868 KB
66Memory accounted for:   #内存使用情况
67        Total accounted:         1253 KB  14%
68        memPool accounted:       1253 KB  14%
69        memPool unaccounted:     7614 KB  86%
70        memPoolAlloc calls:    167272
71        memPoolFree calls:     169189
72File descriptor usage for squid:
73        Maximum number of file descriptors:   1024  #系统最大file descriptor数
74        Largest file desc currently in use:     39  #目前使用file descriptor最大值
75        Number of file desc currently in use:   33  #目前正在使用的file descriptor数
76        Files queued for open:                   0
77        Available number of file descriptors:  991
78        Reserved number of file descriptors:   100
79        Store Disk files open:                   0
80Internal Data Structures:
81            77 StoreEntries   #Cache中存放的 object 的数量
82            77 StoreEntries with MemObjects  #内存中 object 数量
83            76 Hot Object Cache Items #热点object 的数量
84            50 on-disk objects # 硬盘上的object的数量

上面的-p后面根的是端口，根据自己具体的情况而定。如果是3128端口，就把上面的80换成3128就行了。另外一些常用的squidclient查询语句如下：

1squidclient -p 80 mgr:info      #取得squid运行状态信息：
2squidclient -p 80 mgr:mem     #取得squid内存使用情况：
3squidclient -p 80 mgr:objects #取得squid已经缓存的列表,使用时要小心，可能会造成squid崩溃：
4squidclient -p 80 mgr:diskd  #取得squid的磁盘使用情况：
5squidclient -p 80 -m PURGE https://blog.361way.com  #强制更新某个url,即清理某连接的squid