3.5.4 Shared resource inheritance timeout
This subsection explains the function for monitoring the inheritance of shared resources (disconnection and connection) during the hot standby operation to see whether the inheritance processing is completed within a time limit. The timeout is monitored only during the hot standby operation. It is not monitored during server startup or termination.
- Organization of this subsection
(1) Processing when a timeout is detected
A time limit is set for the entire processing of disconnecting or connecting the shared resources. If the disconnection or connection processing is not completed within this time limit, processing on the shared resources is cancelled.
If the function for canceling server startup in the event of a shared resource connection error is used and the shared resource connection processing results in a timeout, the server's startup is canceled.
If the start retry function is used during hot standby processing, HA Monitor waits until the server is restarted.
(2) Monitoring range
Monitoring for the time limit is supported for either of the ranges described below. HA Monitor monitors each instance of processing to see whether it is completed within the specified time limit.
-
From the time disconnection of shared resources begins on the hot-standby target host to the time execution of the user command at the start of server failure processing is completed.
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From the time connection of shared resources begins on the hot-standby target host to the time execution of the user command at the start of server hot standby processing is completed
(3) Required environment settings
Set timeout values related to switching (disconnection and connection) of shared resources for the following operands:
-
The dev_timelimit operand in the server environment definition
Specify the timeout value for disconnection and connection of shared resources.
-
The dev_offlimit operand in the server environment definition
Specify the timeout value for disconnection of shared resources.
-
The dev_onlimit operand in the server environment definition
Specify the timeout value for connection of shared resources.
To specify different timeout values for disconnection and connection of shared resources, specify the disconnection timeout value for the dev_offlimit operand, and the connection timeout value for the dev_onlimit operand. Note that if you specify the dev_timelimit operand, you can specify neither the dev_offlimit operand nor the dev_onlimit operand.
The following table describes how the behavior of timeout monitoring changes according to the settings of the dev_timelimit, dev_offlimit, and dev_onlimit operands in the server environment definition.
|
Operand specification |
Behavior of timeout monitoring |
||
|---|---|---|---|
|
dev_timelimit |
dev_onlimit |
dev_offlimit |
|
|
Not specified |
Not specified |
Not specified |
No monitoring is performed. |
|
Specified |
The timeout for disconnection of shared resources is monitored. |
||
|
Specified |
Not specified |
The timeout for connection of shared resources is monitored. |
|
|
Specified |
The timeout for disconnection and connection of shared resources is monitored. |
||
|
Specified |
Not specified |
Not specified |
The timeout for disconnection and connection of shared resources is monitored. |
|
Specified |
This combination is not possible. |
||
|
Specified |
Not specified |
This combination is not possible. |
|
|
Specified |
This combination is not possible. |
||