Oracle® HTTP Server Administrator's Guide 10g Release 1 (10.1) Part Number B12255-01 |
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This chapter discusses Oracle Diagnostic Logging, log formats, and describes various log files and their locations.
Topics discussed are:
Documentation from the Apache Software Foundation is referenced when applicable.
Oracle offers a new method for reporting diagnostic messages. This new method, Oracle Diagnostic Logging (ODL), presents a common format for diagnostic messages and log files, and a mechanism for correlating all diagnostic messages from various components across Oracle Database. Using ODL, each component logs messages to its own private local repository. A tool called LogLoader
collects messages from each repository and loads them into a common repository where messages can be viewed as a single log stream, or analyzed in different ways.
You can view Oracle Database diagnostic log files using a text editor.
See Also:
Oracle Application Server 10g Administrator's Guide for detailed information regarding Oracle Diagnostic Logging. |
Oracle HTTP Server enables you to choose the format in which you want to generate log messages. You can either continue to generate log messages in the legacy Apache message format, or generate log messages using ODL, which complies with the new Oracle-wide standards for generating log messages.
To enable Oracle HTTP Server to use ODL, enter the directives specified in the subsequent section in the httpd.conf
file. Oracle recommends that you enter the directives before any modules are loaded (LoadModule
directive) in the httpd.conf
file so that module-specific logging severities are in effect before modules have the opportunity to perform any logging.
Enables you to switch between ODL and legacy Apache logging facility.
Default: apache
Enables you to set message severity. The message severity specified with this directives is interpreted as the lowest message severity that is desired, and all messages of that severity level and higher will be logged. OraLogSeverity
may be specified multiple times. It can be specified globally (no module_name) and once for each module for which a module-specific logging severity is desired.
This argument is the internal name of a module, as it appears in the module structure. The <IfModule
> directive also makes use of this internal name. The module structure derives the module name from the value of the _FILE_
macro, without path prefix, of the file which defines the module structure. If a module name is not supplied, the OraLogSeverity
directive is applied globally.
If the module name is specified, then the directive overrides the global directive value of all the messages originating from the specified module. Specifying a module name for a module that does not get loaded generates an error.
Message types may be specified in upper or lower case, but will appear in the message output in upper case. This parameter must be of one of the following values:
This parameter must be an integer in the range of 1-32.
Table 6-1 lists some examples of OraLogSeverity
.
If a message level is not specified, then the level defaults to the lowest severity. If the entire directive is omitted, then the value of the global Apache LogLevel
directive is used and translated to the corresponding Oracle message type and the lowest level within the corresponding range, as listed in Table 6-2:
Apache Log Level | Oracle Message Type |
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Specifies the path to the directory which contains all log files. This directory must exit.
Default:
LogFormat
specifies the information included in the log file, and the manner in which it is written. The default format is the Common Log Format (CLF). The CLF format is: host ident authuser date request status bytes
host
: This is the client domain name or its IP number.ident
: If IdentityCheck
is enabled and the client machine runs identd
, then this is the client identity information.authuser
: This is the user ID for authorized user.date
: This is the date and time of the request in the <day/month/year:hour:minute:second>
format.request
: This is the request line, in double quotes, from the client.status
: This is the three-digit status code returned to the client.bytes
: This is the number of bytes, excluding headers, returned to the client.Table 6-3 lists all the different logging levels, their descriptions, and, example messages:
The log files are discussed in the subsequent sections:
It is important to periodically rotate the log files by moving or deleting existing logs on a moderately busy server. For this, the server must be restarted after the log files are moved or deleted so that new log files are opened.
See Also:
"Log Rotation" in the Apache Server documentation. |
The server access log records all requests processed by the server. The location and content of the access log is controlled by the CustomLog
directive. The LogFormat
directive can be used to simplify the selection of the contents of the logs.
See Also:
"Access Log" in the Apache Server documentation. |
The CustomLog
directive is used to log requests to the server. A log format is specified, and the logging can optionally be made conditional on request characteristics using environment variables.
See Also:
" |
The server sends diagnostic information and records error messages to a log file located, by default, in:
The file name can be set using the ErrorLog
directive.
See Also:
" |
When the server is started, it notes the process ID of the parent httpd process to the PID file located by, default, in
This filename can be changed with the PidFile
directive. The process ID is for use by the administrator for restarting and terminating the daemon. If the process dies (or is killed) abnormally, then it is necessary to kill the children httpd processes.
See Also:
"Pid File" in the Apache Server documentation. |
Oracle HTTP Server is capable of writing error and access log files through a pipe to another process, rather than directly to file. This increases the flexibility of logging, without adding code to the main server. In order to write logs to a pipe, replace the file name with the pipe character "|", followed by the name of the executable which should accept log entries on its standard input. Oracle HTTP Server starts the piped-log process when the server starts, and restarts it if it crashes while the server is running.
See Also:
"Piped Log" in the Apache Server documentation. |
Rewrite Log is necessary for debugging when mod_rewrite
is used. This log file produces a detailed analysis of how the rewriting engine transforms requests. The level of detail is controlled by the RewriteLogLevel
directive.
See Also:
"Rewrite Log" in the Apache Server documentation. |
Script Log enables you to record the input to and output from the CGI scripts. This should only be used in testing, and not for live servers.
See Also:
"Script Log" in the Apache Server documentation. |
When Oracle HTTP Server starts in SSL mode, it creates ssl_engine_log
and ssl_request_log
in
ssl_engine_log
tracks SSL and protocol issues, where as ssl_request_log
records user activity. Use the SSLLogFile
directive to control output.
Transfer Log specifies the file in which to store the log of accesses to the site. If it is not explicitly included in the conf
file, then no log is generated. The server typically logs each request to a transfer file located, by default, in
The filename can be set using a CustomLog
directive.