Changing the TREX Host Name of the Master Name Server

Prerequisites

You have stopped TREX on all hosts.

Context

You want to change the host name of the master name server. Proceed as follows:

Change the TREX Configuration Files

The process flow for the configuration depends on the type of data storage that you have chosen for your distributed landscape:
- Process flow for decentralized storage
- Process flow for centralized storage
Change the profiles settings.

Procedure

Change the TREX Configuration Files
Process flow for decentralized storage
1. Change the host name of the master name server on the host of master name server.
  
  For decentralized data storage, you first change the host name of a master name server in the configuration files topology.ini, sapprofile.ini and TREXWebServer.ini (if the Web server was installed) on the host with the master name server.
2. Change the host name of the master name server on each host in your landscape.
  
  Then you change the host name of this master name server in all sapprofile.ini files on each host in your distributed landscape
3. Change the host name of the master name server on the master index server.
  
  Finally you change the host name of the master name server in the topology.ini files of the master index servers.
Figure 1: Example Scenario

Procedure

Change the host name of the master name server.
1. Change the file <TREX_INSTANCE>\topology.ini on this TREX host with the master name server.
  - You have to change the TREX host name in several places in the topology.ini configuration file (for example: <host>, url=, user=, sap_retrieval_path=).
  - Open the file, search for your old TREX host name, replace it with <new_trex_hostname> and save the file.
2. Change the file <TREX_INSTANCE>\sapprofile.ini on this TREX host with the master name server. Replace the old TREX host name in the configuration file sapprofile.ini with the new TREX host name <new_trex_host name>. Change the line #SAPLOCALHOST= to SAPLOCALHOST= <new_trex_host name>.
  
  Caution
  You have to remove the sign # in front of SAPLOCALHOST so that the command SAPLOCALHOST can be executed.
3. Change the old TREX host name to <new_trex_hostname> in the <TREX_INSTANCE>\TREXWebServer.ini configuration file.
  
  Note
  You have to change the TREXWebServer.ini only if you have installed the Web Server. Navigation to the [HTTPSERVER] section and replace the old TREX host name: URL=http://<new_trex_host_name>.<URL>:...
Change the host name of the master name server on each host in your landscape.

Change the file <TREX_INSTANCE>\sapprofile.ini on all hosts in your TREX landscape. The host names of all master name servers in a TREX landscape are listed in the file sapprofile.ini on each host of your landscape.

Example
# TREX-NameServer

. . .

TREX/NameServer/Master=pwdf2832:30001 pwdf2833:30101 pwdf2834:30201

Replace the old host name of the master name server in your TREX landscape in this list with the new host name. You have to do this on each host in your landscape.
Change the host name of the master name server on the master index server.

Change the old TREX host name to <new_trex_hostname> in the <TREX_INSTANCE>\topology.ini configuration file on the master index server.
- You have to make this change in the topology.ini configuration files on all master hosts (TREX hosts with the role of master index server) in your distributed TREX landscape.
- You have to change the TREX host name in several places in the topology.ini configuration file (for example: <host>, url=, user=, sap_retrieval_path=).

	Hosts	topology.ini	sapprofile.ini	TREXWebServer.ini
1.	Master host 2 as master name server	Change old host to new host name	Change old host to new host name	Change old host to new host name
2.	Slave host 1	---------------	# TREX-NameServer change the host name of the master name server
2.	Slave host 2	---------------	# TREX-NameServer change the host name of the master name server
3.	Master host 1 as master name server	Change old host to new host name	# TREX-NameServer change the host name of the master name server

Master host= host with the role of master index server

Slave host= host with the role of slave index server

Backup host = host with the role of backup index server

Process flow for centralized storage
1. Change the host name of the master name server on the host of master name server.
  
  For centralized data storage, you first change the host name of a master name server in the configuration files sapprofile.ini and TREXWebServer.ini (if Web server was installed) on the host with the master name server.
2. Change the host name of the master name server on each host in your landscape.
  
  Then you change the host name of this master name server in all sapprofile.ini files on each host in your distributed landscape
3. Change the host name of the master name server on the central file server.
  
  Finally you change the host name of the master name server once in the topology.ini file which is stored centrally on the file server.
Figure 2: Example Scenario

Procedure

Change the host name of the master name server on the host of master name server.
1. Change the file <TREX_INSTANCE>\sapprofile.ini on this TREX host with the master name server. Replace the old TREX host name in the configuration file sapprofile.ini with the new TREX host name <new_trex_host name>. Change the line #SAPLOCALHOST= to SAPLOCALHOST= <new_trex_host name>.
  
  Caution
  You have to remove the sign # in front of SAPLOCALHOST so that the command SAPLOCALHOST can be executed.
2. Change the old TREX host name to <new_trex_hostname> in the <TREX_INSTANCE>\TREXWebServer.ini configuration file.
  
  Note
  You have to change the TREXWebServer.ini only if you have installed the Web Server.
  
  Navigation to the [HTTPSERVER] section and replace the old TREX host name: URL=http://<new_trex_host_name>.<URL>:...
Change the host name of the master name server on each host in your landscape.

Change the file <TREX_INSTANCE>\sapprofile.ini on all hosts in your TREX landscape. The host names of all master name servers of a TREX landscape are listed in the file sapprofile.ini on each host in your landscape.

Example
# TREX-NameServer

. . .

TREX/NameServer/Master=pwdf2832:30001 pwdf2833:30101 pwdf2834:30201

Replace the old host name of the master name server in your TREX landscape in this list with the new host name. You have to do this on each host in your landscape.
Change the host name of the slave name server on the central file server.

Change the old TREX host name to <new_trex_hostname> in the <TREX_INSTANCE>\topology.ini configuration file on the central file server.
- You have to do this once in the configuration file topology.ini on the file server in your distributed TREX landscape. In these topology.ini files, the host names of all slave name server in your TREX landscape are listed.
- You have to change the TREX host name in several places in the topology.ini configuration file (for example: <host>, url=, user=, sap_retrieval_path=).

Hosts	sapprofile.ini	TREXWebServer.ini	topology.ini
Master host as master name server	Change old host to new host name	# TREX-Name Server Change the host names of the master name servers	---------------
Slave host 1	Change old host to new host name	---------------	---------------
Slave host 2	Change old host to new host name	---------------	---------------
Backup host	Change old host to new host name	---------------	---------------
File server	---------------	---------------	Change old host to new host name

Master host= host with the role of master index server

Slave host= host with the role of slave index server

Backup host = host with the role of backup index server

File server= server for the centrally stored data

Changing the Profile Settings

After changing the TREX configuration files you change the profile settings as described in Changing the Profile Settings.

Results

You have changed the TREX host name for the master name server. You can now restart TREX.