Health management comes equipped with smart defaults that accommodate
most environments. However, if you discover that your health controller is
not working the way you want, then tune the default parameters.
Before you begin
Verify that you have proper security authorization in the console
to modify these settings. Privileges for health policies differ, depending
on the administrative role of the user. Roles include monitor, operator,
configurator, and administrator. If you are a user with either a monitor
or an operator role, you can only view health policy information. If you
are a user with either a configurator or an administrator role, you have all
configuration privileges for health policies.
About this task
Use the following steps to modify the health controller parameters.
Tune these parameters when the health management infrastructure is not working
the way that you want.
Procedure
- Access the health controller settings in the administrative console
by clicking Operational policies > Autonomic managers > Health controller.
- Determine whether you want your changes to be persistent or applied
to the current runtime for testing purposes. This page is divided
into two tabs: Configuration and Runtime. With the Configuration tab, you
can look at fields that are previously configured, and in some cases, make
edits to those fields. With the Runtime tab, you can view the fields that
are currently used by the health controller, and in some cases, make changes
to these values. In contrast to the Configuration tab, these changed values
are sent directly to the health controller to change the parameters that the
controller uses. These changes are not stored into the repository by default,
allowing the user to make a temporary change to the parameters that are not
persisted.
Tip: Apply your changes to the Runtime tab and test
the changes before committing them. You can select Save to configuration in
the Runtime tab, so you can make configuration changes and test them in the
runtime. After you are sure that you want to commit those changes permanently,
click Save to configuration.
- Modify and test your settings.
Control Cycle Length |
Specifies the time between consecutive health checks.
The value is specified in minutes and ranges from 1 to 60 minutes. Longer
control cycles reduce the health monitoring load. The disadvantage is that
health conditions that occur during that period are not detected until the
next control cycle. For example, if you have a health policy with a workload
condition of 10,000 requests associated to an application server and the value
is specified as 60 minutes, the health controller checks every 60 minutes
to determine if the application server has served 10,000 requests. If it has
serves 9,999 requests when it checks, it checks again for another 60 minutes
(the control cycle length), so the server can actually serve more than 10,000
requests prior to a restart. |
Maximum Consecutive Restarts |
Specifies the number of attempts to revive an application
server after a restart decision is made. If this number is exceeded, the assumption
is that the operation failed and restarts are disabled for the server. The
value must be a whole number between 1 and 5, inclusive. |
Minimum Restart Interval |
Controls the minimum amount of time that must elapse
between consecutive restarts of an application server instance. If a health
condition for an application server is breached during that time, the restart
is set to a pending state. When the minimum restart interval passes, the restart
occurs. The value can range from 15 minutes to 365 days, inclusive. A value
of 0 disables the minimum restart value. |
Restart Timeout |
Consists of the sequence of stop and start server actions.
The restart timeout specifies how long to wait for a server to stop before
explicitly checking its state and attempting startup. If the length of time
to start and stop an application server is unusually high, you might want
to set this value accordingly, so that the restart action does not time out.
Always specify the value in minutes. The value can range from 1 minute to
60 minutes, specified as a whole number. |
Enable Health Monitoring |
Enables or disables the operation of the health controller.
When enabled, the health controller continuously monitors the health policies
in the system. You can disable the health controller without removing the
health policies from the system. |
Prohibited Restart Times |
Specifies the times and days of the week during which
a restart of an application server instance is prohibited. Specify the start
and end times by selecting the hour and minute using a 24 hour clock and by
selecting the days of the week. You can specify multiple time blocks, if
needed. If you specify a start time and end time, you must also specify at
least one day of the week that these times are prohibited. The block between
the start time and end time cannot cross the midnight boundary. If you need
to specify a block of, for example, 10:00 PM to 1:00 AM, you need to specify
two blocks, one from 22:00 to 23:59 and one from 00:00 to 01:00. Click Add to
add additional time constraints.
You can remove an existing constraint
by selecting the check box next to the constraint and by clicking the Remove.
As with the minimum restart interval, a restart for a health condition that
is violated is delayed until after a prohibited time interval passes.
|
Results
You have modified the health management configuration settings to
tune your system.
What to do next
See
Troubleshooting health management
for more information
about modifying the health management settings when they are not working the
way that you want.