Configuration --- KAAS Server Monitor

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Home > Product > KSM > Configuration

The KSM follows a simple logic in executing its state machine:

KSM says hello to server periodically, and checks server response. If the response is invalid, there is a instance of failure. When there is a certain of numbers of failure instance reached, a server failure event is reported. KSM can be configured to send failure report and take necessary actions.

To be more Specific:

KSM can say hello(aloha) peridically via executing a external shell command or perform a HTTP GET (fetch a web page of specific URL).

The returns of hello is checked against pre-defined logic (*1, *2, *3) to determind whether the response is valid or not.

If the response is invalid, the failure instance is increased by one. However, whenever there is a valid response, the failure instance is reset to zero. If the failure instance is counted to a threshould, a set of actions are taken.

These actions may include server maintainence , report generation (*1, *2), and notification (*1, *2, *3)

To activate KSM, you should at least specify a method to say aloha by setting either ALOHA_URL or ALOHA_CMD.

Some directives are marked with supporting "strftime format string", it means the value of these directives will be randered through C funtion strftime (2) at run-time. Take FAIL_EMAIL_TITLE for instance, if the value of FAIL_EMAIL_TITLE is 'KSM Failure at %F %r', the '%F' and '%r' will be replaced with current time according to the format string defined by strftime (2). For example, they become '2004-12-01' and '02:32:54 p.m.'.

Besides those directives mentioned above, there are also many other directives can be used to fine tune the run-time behaviors of KSM. Please read the comments in 'ksm.conf' for more details.

A sample 'ksm.conf':


# Say aloha by fetching web page of specify URL.
# The ALOHA_URL is performed before ALOHA_CMD, if they are both supplied
# Example:
#	ALOHA_URL=http://127.0.0.1/index.html
#
# Default: (none)
ALOHA_URL=


# Say aloha by executing a shell command.
# The ALOHA_URL is performed before ALOHA_CMD, if they are both supplied
# Example
#	ALOHA_CMD=ping 192.168.0.254
#
# Default: (none)
ALOHA_CMD=


# Check whether the aloha response is valid or not.
# A valid aloha response resets the failure instance number to zero.
# The ALOHA_CHECK_TRUE is checked before ALOHA_FALSE, if they are both supplied
# Example:
#  The response is not checked
#	ALOHA_CHECK_TRUE=		
#
#  The response should identical to the string "I am fine"
#	ALOHA_CHECK_TRUE==I am fine
#
#  The response constains the string "virus found"
#	ALOHA_CHECK_TRUE=virus found
#
#  The response starts with the string "200"
#	ALOHA_CHECK_TRUE=^200
#
# Default: (none)
ALOHA_CHECK_TRUE=


# Check whether the aloha response is invalid or not.
# An invalid aloha response increase the failure instance number by one.
# The ALOHA_CHECK_TRUE is checked before ALOHA_FALSE, if they are both supplied
# Example:
#  The response is not checked
#	ALOHA_CHECK_FALSE=		
#
#  The response should identical to the string "I am fine"
#	ALOHA_CHECK_FALSE==I am fine
#
#  The response constains the string "virus found"
#	ALOHA_CHECK_FALSE=virus found
#
#  The response starts with the string "200"
#	ALOHA_CHECK_FALSE=^200
#
# Default: (none)
ALOHA_CHECK_FALSE=


# If an aloha response is not determinded to neither valid nor invalid
# by ALOHA_CHECK_TRUE and ALOHA_CHECK_FAILURE, should it be valid or invalid?
# Example:
#	ALOHA_CHECK_DEFAULT=1		
#
# Default: 1 (valid)
ALOHA_CHECK_DEFAULT=



# The shell command to be executed when event of a server fail is detected.
# Example:
#	KAAS_START_CMD=/etc/init.d/named start
#
# Default: (none)
KAAS_START_CMD=


# Should KSM forks a dedicated child process to run shell command specified
# by KAAS_START_CMD. If KSM doesn't fork, KSM will stop and wait the
# shell command exits. Set KAAS_START_FORK to YES, if the shell command
# of KAAS_START_CMD can't exit successfully.
# If KAAS_START_CMD is not set, KAAS_START_FORK has no effects to KSM.
# Example:
#	KAAS_START_FORK=1
#
# Default: 1	(YES)
KAAS_START_FORK=1


# The maximum execution time in seconds to run a shell command of 
# KAAS_START_CMD, if KAAS_START_FORK is set to yes.
# If CLIENT_GRACEFUL is set, the forked KSM child process will terminate
# when specified time limit is reached. Set this value to 0 to cancel it.
# If KAAS_START_FORK is not set to YES, CLIENT_GRACEFUL has no effects to KSM.
# Example:
#	CLIENT_GRACEFUL=5
#
# Default: 0	(no activated)
CLIENT_GRACEFUL=0


# The location of the report file to be mailed when a server failure 
# is detected.
# Example:
#	KAAS_REPORT_FILE=/var/log/vsftpd.log
#
# Default: (none)
# Support strftime format string: YES
KAAS_REPORT_FILE=


# The shell command to be executed when when a server failure is detected.
# The shell command executed is intended for report generation.
# Example:
#	KAAS_REPORT_CMD=
#
# Default: (none)
# Support strftime format string: YES
KAAS_REPORT_CMD=


# A delay in seconds between server failure and before executing the shell commands.
# The shell commands are specified by KAAS_REPORT_CMD and KAAS_NOTIFY_CMD. 
# Example:
#	KAAS_REPORT_DELAY=20
#
# Default: 0	(no delay)
KAAS_REPORT_DELAY=0


# The shell command to be executed when event of a server fail is detected.
# The shell command executed is intended for user defined server failure 
# notification.
# Example:
#	KAAS_NOTIFY_CMD=
#
# Default: (none)
FAIL_NOTIFY_CMD=


# If KAAS_REPORT_FILE is set, the file will be sent to the email address
# specified by FAIL_NOTIFY_EMAIL.
# Example:
#	KAAS_NOTIDY_EMAIL=root, webmaster@abc.com, mis@def.net
#
# Default: (none)
FAIL_NOTIFY_EMAIL=


# The email title to be used when a notification email is sent.
# Example:
#	KAAS_EMAIL_TITLE=Failure/Event detected
#
# Default: KSM Failure detected
# Support strftime format string: YES
FAIL_EMAIL_TITLE=KSM Failure detected


# The web page to be fetched when a server failure detected.
# Example:
#	KAAS_START_CMD=
#
# Default: (none)
FAIL_NOTIFY_URL=


# The shell command to be executed when event of a server fail is detected
# Example:
#	PERSISTANT_NOTIFY=0
#
# Default: 0	(not persistant)
PERSISTANT_NOTIFY=0



# Where the log information should be sent to. If USE_SYS_LOG is set to 1,
# the information is logged via standard syslog (3).
# You can send log messages to both syslog(3) and user defined LOG_FILE.
# Example:
#	USE_SYSLOG=1
#
# Default: 1	(YES)
USE_SYSLOG=1


# You can specify a file to save KSM log messages. 
# You can send log messages to both LOG_FILE and syslog(3) via USE_SYSLOG.
# Example:
#	LOG_FILE=/tmp/ksm.log
#
# Default: (none)
LOG_FILE=


# The number of continous failure instances to be regarded as a failure event.
# Example:
#	MAX_RETRY=1
#
# Default: (none)
MAX_RETRY=1


# The number of seconds between each aloha
# Example:
#	KAAS_START_CMD=
#
# Default: (none)
SCAN_INTERVAL=5


# The log message should be dumped on terminal or not.
# Example:
#	VERBOSE=0
#
# Default: 0  (don't dump on terminal)
VERBOSE=0