Linux Web Server Web site Failure Analysis common commands _linux

Linux Web Server Web site failure analysis, the specific contents are as follows

System Connection Status article:

1. View TCP connection Status

Netstat-nat |awk ' {print $} ' |sort|uniq-c|sort-rn

netstat-n | awk '/^tcp/{++s[$NF]}; End {for (a in S) print A, s[a]} ' or
netstat-n | awk '/^tcp/{++state[$NF]}; End {for (key) print key, "\ T", State[key]} '
netstat-n | awk '/^tcp/{++arr[$NF]}; End {to (k in arr) print K, "T", arr[k]} '

netstat-n |awk '/^tcp/{print $NF} ' |sort|uniq-c|sort-rn

netstat-ant | awk ' {print $NF} ' | Grep-v ' [A-z] ' | Sort | Uniq-c

2. Find requests 20 IP (often used to find the source of attack):

Netstat-anlp|grep 80|grep Tcp|awk ' {print $} ' |awk-f: ' {print $} ' |sort|uniq-c|sort-nr|head-n20 netstat-ant |awk
'/:80/{split ($5,ip, ":"); ++a[ip[1]]}end{for (i in A) print A[i],i} ' |sort-rn|head-n20

3. Use tcpdump to sniff the 80-port access to see who is the tallest

Tcpdump-i ETH0-TNN DST Port 80-c 1000 | Awk-f "." ' {print $. ' $ "." $ "." $} ' | Sort | uniq-c | Sort-nr |head-20

4. Find more time_wait connections

Netstat-n|grep Time_wait|awk ' {print $} ' |sort|uniq-c|sort-rn|head-n20

5. Search for more SYN connections

Netstat-an | grep SYN | awk ' {print $} ' | Awk-f: ' {print $} ' | Sort | uniq-c | Sort-nr | More

6. According to the port column process

NETSTAT-NTLP | grep 80 | awk ' {print $} ' | Cut-d/-F1

Web log Analysis 1 (Apache):

1. Access to the top 10 IP addresses

Cat Access.log|awk ' {print} ' |sort|uniq-c|sort-nr|head-10
cat Access.log|awk ' {counts[$ (11)]+=1}; End {to (URL in counts) print Counts[url], url} '

2. The most visited file or page, take the top 20

Cat Access.log|awk ' {print $11} ' |sort|uniq-c|sort-nr|head-20

3. List the maximum number of EXE files to transmit (when analyzing download stations)

Cat Access.log |awk ' ($7~/.exe/) {print $ "$" "$" "$}" |sort-nr|head-20

4. list exe files with output greater than 200000byte (about 200kb) and the number of corresponding file occurrences

Cat Access.log |awk ' ($ > 200000 && $7~/.exe/) {print $} ' |sort-n|uniq-c|sort-nr|head-100

5. If the last column of the log records the paging file transfer time, there are the most time-consuming pages listed to the client

Cat Access.log |awk ' ($7~/.php/) {print $NF "$" "$" "$}" |sort-nr|head-100

6. List the most time-consuming pages (more than 60 seconds) and the number of corresponding page occurrences

Cat Access.log |awk ' ($NF > && $7~/.php/) {print $} ' |sort-n|uniq-c|sort-nr|head-100

7. List files with a transmission time of more than 30 seconds

Cat Access.log |awk ' ($NF >) {print $} ' |sort-n|uniq-c|sort-nr|head-20

8. Statistics website Traffic (G)

Cat Access.log |awk ' {sum+=$10} end {print sum/1024/1024/1024} '

9. Statistics 404 of the Connection

Awk ' ($ ~/404/) ' Access.log | awk ' {print $9,$7} ' | Sort

10. Statistics HTTP Status

Cat Access.log |awk ' {counts[$ (9)]+=1}; End {for (code in counts) print code, Counts[code]} '
Cat Access.log |awk ' {print $} ' |sort|uniq-c|sort-rn

11. Spider analysis to see which spiders are crawling content.

/usr/sbin/tcpdump-i Eth0-l-S 0-w-DST Port 80 | Strings | Grep-i User-agent | Grep-i-E ' bot|crawler|slurp|spider '

Website Day Analysis 2 (Squid article) statistics by domain flow

Zcat squid_access.log.tar.gz| awk ' {print $10,$7} ' |awk ' begin{fs= ' [/] '}{trfc[$4]+=$1}end{for (domain in TRFC) {printf '%st%dn ', Domain,trfc[domain]}} '

Database articles

1. View SQL for database execution

/usr/sbin/tcpdump-i eth0-s 0-l-w-dst Port 3306 | Strings | Egrep-i ' select| update| delete| Insert| Set| Commit| rollback| create| drop| alter| Call '

System Debug Analysis Chapter

1. Debug command

Strace-p PID

2. Track the PID of the specified process

Gdb-p PID

The above is the entire content of this article, I hope to help you learn, but also hope that we support the cloud habitat community.