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* 2015-09-07 write an apache2 access log parser in haskell.
practice using attoparsec.
LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\" %D" keystone
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10.21.176.7 - - [06/Sep/2015:06:26:02 +0800] "GET /v3/auth/tokens HTTP/1.1" 200 3997 "-" "-" 1011068
10.21.176.7 - - [06/Sep/2015:06:26:03 +0800] "GET /v3/auth/tokens HTTP/1.1" 200 4065 "-" "python-requests/2.2.1 CPython/2.7.3 Linux/3.13.0-38-generic" 5481
10.21.176.7 - - [06/Sep/2015:06:26:02 +0800] "GET /v2.0/tokens/e79ce79f16f04852a7d981009090fb75 HTTP/1.1" 200 2692 "-" "python-requests/2.2.1 CPython/2.7.3 Linux/3.13.0-40-generic" 879293
10.21.176.7 - - [06/Sep/2015:06:50:02 +0800] "POST /v2.0/tokens HTTP/1.1" 200 2615 "-" "python-neutronclient" 211874238
allow me to
- filter slow requests.
-gt 2s
- find most frequent request.
order by request verb and path frequency.
print out first N most frequently viewed verb&path.
get top 5 request
cd /var/log/apache2
~sylecn/a2p -i access.keystone.admin.ssl.log -t 5
stack build && stack exec a2p -- -i ~/d/t1 --top 1
output for user:
M% COUNT POST xxx
M% COUNT GET xxx
return value for this
Map (verb, path) count
Order by count.
get first N.
filter the map before converting to alist.
- how to do insert or update? when doing counting.
you have to use lookup. it's probably not thread safe.
- works perfectly on production access log.
how to use the parser?
a2p -i ACCESS_LOG_FILE [-gt 20s]
- created project at ~/haskell/apache2-log-parser
- let's test parse efficiency first.
print a summary line:
parsed N input lines in M seconds. (P line/s)
- support -f param and parsing lines from file.
- can't convert duration to Int easily.
- Applicative is powerful. I didn't know about <* before.
logParser :: Parser [AccessLog]
logParser = many $ parseLine <* endOfLine
- how to use int type param in optparse-applicative?
haskell - How to use Int with the optparse-applicative inside a data constructor? - Stack Overflow
http://stackoverflow.com/questions/31636962/how-to-use-int-with-the-optparse-applicative-inside-a-data-constructor