运维之路

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。

[root@localhost squid]# squidclient -p 80 mgr:info
HTTP/1.0 200 OK
Server: squid/3.1.10
Mime-Version: 1.0
Date: Mon, 26 Nov 2012 14:41:51 GMT
Content-Type: text/plain
Expires: Mon, 26 Nov 2012 14:41:51 GMT
Last-Modified: Mon, 26 Nov 2012 14:41:51 GMT
X-Cache: MISS from cache.361way.com
X-Cache-Lookup: MISS from cache.361way.com:80
Via: 1.0 cache.361way.com (squid/3.1.10)
Connection: close
Squid Object Cache: Version 3.1.10
Start Time:     Mon, 26 Nov 2012 13:18:50 GMT
Current Time:   Mon, 26 Nov 2012 14:41:51 GMT
Connection information for squid:
        Number of clients accessing cache:      34
        Number of HTTP requests received:       774
        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:   9.3   #每分钟http request的数量
        Average ICP messages per minute since start:    0.0
        Select loop called: 637052 times, 7.818 ms avg
Cache information for squid:
        Hits as % of all requests:      5min: 77.1%, 60min: 58.8%   #Cache Request命中率
        Hits as % of bytes sent:        5min: 28.4%, 60min: 20.4%   #Cache Byte命中率
        Memory hits as % of hit requests:       5min: 43.9%, 60min: 32.0%
        Disk hits as % of hit requests: 5min: 0.0%, 60min: 0.2%
        Storage Swap size:      328 KB  #存放cache的硬盘使用大小
        Storage Swap capacity:   0.0% used, 100.0% free
        Storage Mem size:       436 KB   #存放cache的内存使用大小
        Storage Mem capacity:    0.1% used, 99.9% free
        Mean Object Size:       6.56 KB
        Requests given to unlinkd:      2
Median Service Times (seconds)  5 min    60 min:
        HTTP Requests (All):   0.06286  0.06286
        Cache Misses:          0.32154  0.20843
        Cache Hits:            0.00000  0.00000
        Near Hits:             0.06286  0.06286
        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:        4980.301 seconds
        CPU Time:       1.379 seconds
        CPU Usage:      0.03%
        CPU Usage, 5 minute avg:        0.09%
        CPU Usage, 60 minute avg:       0.03%
        Process Data Segment Size via sbrk(): 7508 KB
        Maximum Resident Size: 59728 KB
        Page faults with physical i/o: 0
Memory usage for squid via mallinfo():
        Total space in arena:    7640 KB
        Ordinary blocks:         7587 KB     61 blks
        Small blocks:               0 KB      0 blks
        Holding blocks:          1228 KB      5 blks
        Free Small blocks:          0 KB
        Free Ordinary blocks:      52 KB
        Total in use:            8815 KB 99%
        Total free:                52 KB 1%
        Total size:              8868 KB
Memory accounted for:   #内存使用情况
        Total accounted:         1253 KB  14%
        memPool accounted:       1253 KB  14%
        memPool unaccounted:     7614 KB  86%
        memPoolAlloc calls:    167272
        memPoolFree calls:     169189
File descriptor usage for squid:
        Maximum number of file descriptors:   1024  #系统最大file descriptor数
        Largest file desc currently in use:     39  #目前使用file descriptor最大值
        Number of file desc currently in use:   33  #目前正在使用的file descriptor数
        Files queued for open:                   0
        Available number of file descriptors:  991
        Reserved number of file descriptors:   100
        Store Disk files open:                   0
Internal Data Structures:
            77 StoreEntries   #Cache中存放的 object 的数量
            77 StoreEntries with MemObjects  #内存中 object 数量
            76 Hot Object Cache Items #热点object 的数量
            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：

squidclient -p 80 mgr:info      #取得squid运行状态信息：
squidclient -p 80 mgr:mem     #取得squid内存使用情况：
squidclient -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：
squidclient -p 80 mgr:diskd  #取得squid的磁盘使用情况：
squidclient -p 80 -m PURGE http://www.361way.com  #强制更新某个url,即清理某连接的squid