使用awk统计最大值、最小值、平均值

使用awk统计最大值、最小值、平均值

 

帮同事处理问题时遇到一个需求，从日志中查询当天某个值的最大值、最小值、平均值，最终通过两种方式实现：

 

1、使用sort排序，求最大值、最小值，使用for循环求平均值：

grep RenewalCheckIbatisDAO.*getHistoryPolicyListByLicenceNo pafa.log |awk -F'time=' '{print $2}'|awk -F'ms' '{a[NR]=$1}  END{b=0;c=a[1];d=a[1];for (i in a){b=b+a[i];if(c>a[i])c=a[i];if (d<a[i]) d=a[i]};print "Min:"c,"Max:"d,"Avg:"b/NR}'

 

2、使用for循环+if判断求最大值、最小值、平均值：

grep RenewalCheckIbatisDAO.*getHistoryPolicyListByLicenceNo pafa.log.2013-05-19 |awk -F'time=' '{print $2}'|awk -F'ms' '{a[NR]=$1}  END{b=0;c=a[1];d=a[1];for (i in a){b=b+a[i];if(c>a[i])c=a[i];if (d<a[i]) d=a[i]};print "Min:"c,"Max:"d,"Avg:"b/NR}'

 

经过测试在500W的日志中两者的效率差不多：

[pub_log_mon@cnsz031500 pa18shopauto]$ wc -l pafa.log.2013-05-19

5038206 pafa.log.2013-05-19

 

[pub_log_mon@cnsz031500 pa18shopauto]$ time(grep RenewalCheckIbatisDAO.*getHistoryPolicyListByLicenceNo pafa.log.2013-05-19 |awk -F'time=' '{print $2}'|awk -F'ms' '{print $1| "sort -n"}' | awk '{a[NR]=$1}  END{for (i in a)b=b+a[i];print "Min:"a[1],"Max:"a[NR],"Avg:"b/NR}')

Min:0 Max:1029 Avg:45.0941

real 0m2.450s

user 0m0.893s

sys 0m1.613s

 

[pub_log_mon@cnsz031500 pa18shopauto]$ time(grep RenewalCheckIbatisDAO.*getHistoryPolicyListByLicenceNo pafa.log.2013-05-19 |awk -F'time=' '{print $2}'|awk -F'ms' '{a[NR]=$1}  END{b=0;c=a[1];d=a[1];for (i in a){b=b+a[i];if(c>a[i])c=a[i];if (d<a[i]) d=a[i]};print "Min:"c,"Max:"d,"Avg:"b/NR}')

Min:0 Max:1029 Avg:45.0941

real 0m2.432s

user 0m0.895s

sys 0m1.571s