SAP Web Dispatcher HTTP Log Test

The SAP Web Dispatcher, automatically creates a dev_http_access_log in the SAP WEB DISPATCHER directory to which errors/warnings captured during installation, configuration and control (starting/stopping) of the SAP Web Dispatcher are recorded. By periodically parsing this dev_http_access_log and retrieving the details of error/warning events logged therein, you can understand which activities failed and why. This test helps you do just that.

Target of the test : A SAP Web Dispatcher

Agent deploying the test : An internal agent

Outputs of the test : One set of results for each error type detected in the target SAP Web Dispatcher being monitored.

Configurable parameters for the test

Test period

How often should the test be executed

Host

Specify the host for which the test is to be configured.

Port

The port number at which the specified host listens.

AlertFile

Specify the full path to the log file to be monitored. Since the dev_http_access_log is by default found in the SAP Web Dispatcher directory, the same is displayed here by default.

Also, instead of a specific log file path, the path to the directory containing the error_log files can be provided - eg., /opt/egurkha/manager/logs. This ensures that eG Enterprise monitors the most recent log files in the specified directory. Specific log file name patterns can also be specified. For example, to monitor the latest log files with names containing the string dev_http_access_log, the parameter specification can be, /opt/egurkha/manager/*dev_http_access_log*. Here, '*' indicates leading/trailing characters (as the case may be). In this case, the eG agent first enumerates all the log files in the specified path that match the given pattern, and then picks only the latest log file from the result set for monitoring.    

Every time this test is executed, the eG agent verifies the following:

  • Whether any changes have occurred in the size and/or timestamp of the log files that were monitoring during the last measurement period;
  • Whether any new log files (that match the AlertFilespecification) have been newly added since the last measurement period;

If a few lines have been added to a log file that was monitored previously, then the eG agent monitors the additions to that log file, and then proceeds to monitor newer log files (if any). If an older log file has been overwritten, then, the eG agent monitors this log file completely, and then proceeds to monitor the newer log files (if any).

SearchPattern

Enter the specific patterns of alerts to be monitored. The pattern should be in the following format: <PatternName>:<Pattern>, where <PatternName> is the pattern name that will be displayed in the monitor interface and <Pattern> is an expression of the form - *expr* or expr or *expr or expr*, etc. A leading '*' signifies any number of leading characters, while a trailing '*' signifies any number of trailing characters. Multiple search patterns can be specified as a comma-separated list. If you want all the messages in a log file to be monitored, then your specification would be: <PatternName>:*.

By default, this test monitors error and warning events logged in the dev_http_access_log file. Therefore, the default SearchPattern is set as: ConnectionError:*ERROR*,warn:*WARN*. This indicates that by default, the test will monitor only those lines in the dev_http_access_log which embed the strings ERROR and WARN.

Lines

Specify two numbers in the format x:y. This means that when a line in the alert file matches a particular pattern, then x lines before the matched line and y lines after the matched line will be reported in the detail diagnosis output (in addition to the matched line). The default value here is 0:0. Multiple entries can be provided as a comma-separated list. 

If you give 1:1 as the value for Lines, then this value will be applied to all the patterns specified in the SearchPattern field. If you give 0:0,1:1,2:1 as the value for Lines and if the corresponding value in the SearchPattern filed is like ORA:ORA-*,offline:*offline*,online:*online then:

0:0 will be applied to ORA:ORA-* pattern

1:1 will be applied to offline:*offline* pattern

2:1 will be applied to online:*online pattern

ExcludePattern

Provide a comma-separated list of patterns to be excluded from monitoring in the ExcludePattern text box. For example *critical*,*exception*. By default, this parameter is set to 'none'

UniqueMatch

By default, the UniqueMatch parameter is set to False, indicating that, by default, the test checks every line in the log file for the existence of each of the configured SearchPattern. By setting this parameter to True, you can instruct the test to ignore a line and move to the next as soon as a match for one of the configured patterns is found in that line. For example, assume that Pattern1:*fatal*,Pattern2:*error* is the SearchPattern that has been configured. If UniqueMatch is set to False, then the test will read every line in the log file completely to check for the existence of messages embedding the strings 'fatal' and 'error'. If both the patterns are detected in the same line, then the number of matches will be incremented by 2. On the other hand, if UniqueMatch is set to True, then the test will read a line only until a match for one of the configured patterns is found and not both. This means that even if the strings 'fatal' and 'error' follow one another in the same line, the test will consider only the first match and not the next. The match count in this case will therefore be incremented by only 1.

RotatingFile

This flag governs the display of descriptors for this test in the eG monitoring console. This flag governs the display of descriptors for this test in the eG monitoring console. This flag is set to False by default. In this case, the descriptors of the test will be of the following format: <Alert_file_name>:<SearchPattern>.

If this flag is set to True and the AlertFile text box contains the full path to a specific (log/text) file, then, the descriptors of this test will be displayed in the following format: Directory_containing_monitored_file:<SearchPattern>. Since the alertfileparameter is set to /manager/logs/dev_http_access_log by default in the case of this test, setting the RotatingFile to True will display descriptors in the following format in the eG monitoring console: /manager/logs/ dev_http_access_log:<SearchPattern>

On the other hand, if this flag is set to true and the AlertFile parameter is set to the directory containing log files (say, /manager/logs), then, the descriptors of this test will be displayed in the format: Configured_directory_path:<SearchPattern> - i.e., /manager/logs:<SearchPattern>. On the other hand, if the RotatingFile parameter had been set to False, then the descriptors will be of the following format: Configured_directory:<SearchPattern> - i.e., logs:<SearchPattern> in the case of the example above.

If this flag is set to True and the AlertFile parameter is set to a specific file pattern, then, the descriptors of this test will be of the following format: <FilePattern>:<SearchPattern>. /opt/egurkha/manager/*dev_http_access_log*, and RotatingFile is set to True, then, your descriptor will be: *error_log*:<SearchPattern>. In this case, the descriptor format will not change even if the RotatingFile flag status is changed.

CaseSensitive

This flag is set to No by default. This indicates that the test functions in a 'case-insensitive' manner by default. This implies that, by default, the test ignores the case of your AlertFile and SearchPattern specifications. If this flag is set to Yes on the other hand, then the test will function in a 'case-sensitive' manner. In this case therefore, for the test to work, even the case of your AlertFile and SearchPattern specifications should match with the actual.

OverwrittenFile

By default, this flag is set to False. Set this flag to True if you want the test to support the 'roll over' capability of the specified AlertFile. A roll over typically occurs when the timestamp of a file changes or when the log file size crosses a pre-determined threshold. When a log file rolls over, the errors/warnings that pre-exist in that file will be automatically copied to a new file, and all errors/warnings that are captured subsequently will be logged in the original/old file. For instance, say, errors and warnings were originally logged to a file named dev_http_access_log. When a roll over occurs, the content of the file dev_http_access_log will be copied to a file named dev_http_access_log.1, and all new errors/warnings will be logged in dev_http_access_log. In such a scenario, since the OverwrittenFile flag is set to False by default, the test by default scans only error_log.1 for new log entries and ignores dev_http_access_log. On the other hand, if the flag is set to True, then the test will scan both dev_http_access_log and dev_http_access_log.1 for new entries.

If you want this test to support the 'roll over' capability described above, the following conditions need to be fulfilled:

  • The AlertFile parameter has to be configured only with the name and/or path of one/more alert files. File patterns or directory specifications should not be specified in the AlertFile text box.
  • The roll over file name should be of the format: “<alertfile>.1”, and this file must be in the same directory as the alertfile.

DD Frequency

Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD frequency.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Recent errors

Indicates the number of errors of this type that occurred during the last measurement period.

Number