6.4.4 Differences between jp1hosts and jp1hosts2 information
The following table describes how aspects of JP1/Base operation differ when using jp1hosts information and when using jp1hosts2 information. jp1hosts information is defined for compatibility with JP1/Base Version 9 or earlier. If you establish a new environment, we recommend that you use jp1hosts2 information.
|
No. |
Item |
jp1hosts information |
jp1hosts2 information |
|---|---|---|---|
|
1 |
Restarting JP1/Base to apply the imported definitions |
JP1/Base must be restarted each time you apply the file. |
You do not need to restart JP1/Base when you add an IP address for another host. |
|
2 |
Definitions for physical and logical hosts |
Host definitions are required for physical and logical hosts. |
Host definitions set for physical hosts are merged with those for logical hosts. |
|
3 |
Application to logical hosts in a cluster system |
The file contents need to be imported to the primary and secondary nodes. |
The file contents need to be imported to the primary node only. |
|
4 |
Registration in common definition information |
The file contents are registered with the common definition information. |
The file contents are not registered with the common definition information. The contents are saved as a binary file instead. |
|
5 |
Maximum number of hosts |
No limit. |
Maximum of 10,000. |
|
6 |
Length of single record in definition file |
Maximum of 256 bytes. |
No limit. |
|
7 |
Importing a definition file without a host definition |
Generates an error. |
Results in a valid definition. |
|
8 |
Import a definition file whose settings match the existing definition exactly |
Results in a valid definition. |
Generates an error. |
|
9 |
IPv6 addresses |
Cannot be set. |
Can be set. |
|
10 |
Communication with the event service |
Partially unavailable.# |
Possible. |
- #
-
Even if you set <jp1hosts2> in the address component of the server parameter in the API settings file (api), jp1hosts information cannot be viewed. To use jp1hosts information, as the communication settings for the event service, specify the conventional settings that were used until JP1/Base Version 9.
- Organization of this subsection
(1) Restarting JP1/Base to apply imported definitions
Each time you redefine jp1hosts information, you need to restart JP1/Base, products with JP1/Base as a prerequisite, and programs that have dependency relationships with JP1/Base.
When you add an IP address for a new host to jp1hosts2 information, the change takes effect when you import the definition. You do not need to restart JP1/Base, products with JP1/Base as a prerequisite, and programs that have dependency relationships with JP1/Base on the manager host when you add an agent host to the network. A restart is required for all other definition changes.
(2) Definitions for physical and logical hosts
When using jp1hosts information, the host definitions used for name resolution must be set individually for each physical and logical host.
The jp1hosts2 information on the physical host can merge with the jp1hosts2 information on a logical host. This is called the physical merge mechanism, and is enabled by the +PhysicalMerge parameter in the jp1hosts2 information for the logical host.
The +PhysicalMerge parameter is enabled by default. With the physical merge mechanism enabled, the host definitions in the jp1hosts2 information for the physical host merge with the jp1hosts2 information for the logical host. This means that you do not need to specify a host definition for a logical host, except in circumstances where the logical host needs to resolve to a different IP address from the physical host where it resides.
For details on the +PhysicalMerge parameter, see jp1hosts2 definition file in 16. Definition Files.
- Notes on the physical merge mechanism
-
Note the following when jp1hosts2 information is set for the physical host:
-
jp1hosts information set for the logical host is ignored, and JP1/Base performs name resolution based on the jp1hosts2 information defined for the physical host. This note does not apply to products that do not reference jp1hosts2 information, in which case the specified jp1hosts information will not be ignored.
-
If neither jp1hosts nor jp1hosts2 information is set for a logical host, JP1/Base performs name resolution based on the jp1hosts2 information defined for the physical host.
-
(3) Applying definitions to logical hosts in a cluster system
When you set jp1hosts information for a logical host in a cluster system, you need to import the definition information into the primary and secondary nodes.
When you set jp1hosts2 information for a logical host in a cluster system, if you have imported the definition information to the primary node, there is no need to repeat the process at the secondary node.
(4) Registering definitions with common definition information
jp1hosts information is registered in the common definition information.
On the other hand, jp1hosts2 information is not registered in the common definition information, but in binary files (hostdb{0|1}.bin). For details on the location of these files, see A. List of Files and Directories.
(5) Maximum number of defined hosts
There is no limit to the number of hosts you can define in jp1hosts information.
In jp1hosts2 information, you can define a maximum of 10,000 hosts.
(6) Length of each record in the definition file
jp1hosts information limits the length of each record (line) in the definition file to 256 bytes.
In jp1hosts2 information, there is no limit to the length of the records (lines) in the definition file.
(7) Importing definition files that do not contain host definitions
If you attempt to define jp1hosts information by importing a definition file in which no host definitions exist, an error occurs, the import process stops, and message KAVA0427-E is output.
On the other hand, when defining jp1hosts2 information, the import process will proceed normally if you import a definition file in which no host definitions exist. This means that you can import a definition file containing nothing more than a +DefaultResolve or +PhysicalMerge parameter. You can also import a definition file containing no definitions at all. In this case, the default is set for all parameters.
(8) Importing a definition file that matches the existing definition
With jp1hosts information, if the definition file you import does not result in any changes to the existing jp1hosts information, the update process goes ahead in the usual way.
With jp1hosts2 information, JP1/Base only imports the definition file if it would result in changes to the existing jp1hosts2 information. If there are no changes, the import process stops and message KAVA0456-I is output. When importing a definition file to a logical host, the system uses the result of the physical merge mechanism to check whether the file would result in any changes.
(9) IPv6 addresses
You cannot use IPv6 addresses in jp1hosts information.
In jp1hosts2 information, you can use IPv6 addresses. For details on how to configure JP1/Base to communicate using IPv6 addresses, see 6.11 Using JP1/Base in IPv6 environments.
(10) Communication with the event service
When you use jp1hosts information to resolve the name used for event service communication, specify the conventional settings that were used until JP1/Base Version 9. Specifically, you must explicitly specify the IP addresses for the ports and remote-server parameters in the event server settings file (conf) and for the server parameter in the API settings file (api).
In contrast, jp1hosts2 information can be used to perform name resolution for communication with the event service. By default, a new installation of JP1/Base will use jp1hosts2 information to communicate with the event service. To use jp1hosts2 information in an overwrite installation, you need to modify the event server settings file (conf) and API settings file (api). For details on the changes you need to make, see 6.4.5 Migrating from jp1hosts information to jp1hosts2 information.