This is an additional log to what has been already available in regular server logs and keeps nothing but information regarding HTTP requests in a format used by Apache httpd. This makes it possible to use existing tools in order to parse and extract interesting information out of the logs.
The log is kept in each server's ./logs/http_access.log file. For instance, if a server is in /opt/zato/server1, the log will be in /opt/zato/server1/http_access.log.
Here's a sample entry and descriptions of all the default fields:
10.151.19.27 K070053855728592769928224227915635470962 "zato.ping" [12/Jan/2014:20:11:53 +0100] "GET /zato/ping HTTP/1.1" 200 141 "-" "curl/7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/220.127.116.11 libidn/1.23 librtmp/2.3"
|Remote address||10.151.19.27||Address of the application issuing the request, X-Forwarded-For is used, if present, otherwise IP address of the client application is used.|
|CID||K070053855728592769928224227915635470962||Correlation ID assigned to the request|
|Channel name||"zato.ping"||Name of the channel invoked, either plain HTTP or SOAP|
|Timestamp||[12/Jan/2014:20:11:53 +0100]||Timestamp of the request. In local timezone by default but can be changed to UTC if need be.|
|HTTP info||"GET /zato/ping HTTP/1.1"||HTTP method, URL path invoked and HTTP method|
|Status code||200||HTTP status code returned in response|
|Response size||141||Size of the response in bytes|
|Referer||"-"||HTTP referer (sic), currently not used|
|User agent||"curl/7.22.0 (x86_64-pc-linux-gnu) libcurl/7.22.0 OpenSSL/1.0.1 zlib/18.104.22.168 libidn/1.23 librtmp/2.3"||User agent issuing the request|