Reassigning the server IP address to another server

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If you are using the server IP address to connect your agents to the Cloud APM server, after the server upgrade is finished, you must reassign the IP address of the V8.1.3 Cloud APM server to the upgraded V8.1.4 server and point the V8.1.3 IP address to the host name of the V8.1.4 server.

Important: This procedure describes one method of reassigning the IP address. There are other ways to complete this task. For more information, see the network configuration using the command line interface information in the Networking Guide in Red Hat documentation.

Before you begin

If you plan to install new agents after you reassign the IP address of the server, create new configuration packages for the agent images (see step 2 in Configuring the downloaded images). Otherwise, the agents will not connect to the Cloud APM server or show in the Cloud APM console.

Procedure

Complete the following steps as the root user:

Change the IP address and host name of the server that is used to start the Cloud APM console. This is the address that users enter to start the console from their web browsers, for example: https://myserver:9443 or http://myserver:8080. Change to the install_dir/ccm directory and run the following command:
```
configure_server_address.sh
```
When prompted, enter the new server host name and IP address.
Update the server agent file names. The server agents include the Synthetic Events agent, the Transaction Events agent, and optionally, the Bluemix® Integration agent. Change to the install_dir/serveragents/bin directory and run the following command:
```
update_config_files.sh
```
Reassign the IP address from the V8.1.3 Cloud APM server to the V8.1.4 server:
1. To determine the IP address and the number of network adapters on the 8.1.3 server, run the following command from this server:
```
ip addr
```
2. To determine the IP address and the number of network adapters on the new upgraded V8.1.4 server, run the following command from this server:
```
ip addr
```
3. If there is only one network adapter on the V8.1.3 server, enter the following command to shut down this server system and free up the IP address for reuse:
```
shutdown -P now
```
  If there are multiple network adapters on the V8.1.3 server, enter the following command to shut down the network adapter that is configured with the IP address on the server and free up the IP address for reuse:
```
ip link set dev ADAPTER down
```
  where ADAPTER is the adapter name from sub step 3.a.
4. Enter the following commands on the V8.1.4 server to reassign the V8.1.3 IP address to the V8.1.4 server. This V8.1.3 IP address becomes the IP address for the V8.1.4 server:
```
TEMP=/tmp/adapter.$$ 
sed 's/IPADDR=.*$/IPADDR='"IP"'/' /etc/sysconfig/network-scripts/ifcfg-ADAPTER >$TEMP
```
  where IP is the V8.1.3 server IP address, and ADAPTER is the adapter name from the sub step 3.b.
  Enter the following command to complete the reassignment:
```
cp $TEMP /etc/sysconfig/network-scripts/ifcfg-ADAPTER
```
  Enter this command to restart the network adapter:
```
/etc/init.d/network restart
```
The V8.1.4 network adapter is now using the V8.1.3 IP address as its IP address.
On the V8.1.4 server, open the /etc/hosts file in a text editor of your choice and replace the IP address opposite the V8.1.4 host name with the IP address of the V8.1.3 server.

Note: If you reassigned the V8.1.3 IP address to the V8.1.4 server, you do not have to change the network DNS configuration.
Override the host name of the Cloud APM server in the Central Configuration Services component.
1. If you are not already logged in to the Cloud APM console, log in now.
  (See Starting the Cloud APM console.)
2. Click System Configuration > Advanced Configuration and click Agent Central Configuration.
3. In the Host Name Override field, enter the new IP address or fully qualified host name of the Cloud APM server.
After you click Save, the new host name is updated in the Central Configuration Services component.
If you have reports packages for the Response Time Monitoring Agent and the WebSphere® Applications agent installed, you must reinstall the reports packages for both agents.
For more information, see Installing reports. Restart the Tivoli Common Reporting server, complete the steps in the sub topics under Restarting Jazz for Service Management application servers.
Optional: If at any time you need to restore the original IP addresses to the existing V8.1.3 and upgraded V8.1.4 servers, complete the following steps:
1. To return the IP address on the V8.1.4 server to its original IP address, enter the following commands:
```
TEMP=/tmp/adapter.$$ 
sed 's/IPADDR=.*$/IPADDR='"IP"'/' /etc/sysconfig/network-scripts/ifcfg-ADAPTER >$TEMP
```
  Replace IP in the previous command with the original V8.1.4 server IP address that is being restored and replace ADAPTER with the adapter name from the previous step 3. b.
  
  Enter the following command to complete the reassignment:
```
cp $TEMP /etc/sysconfig/network-scripts/ifcfg-ADAPTER
```
  Issue this command to restart the V8.1.4 network adapter:
```
/etc/init.d/network restart
```
2. If there is only one network adapter on the V8.1.3 server system and the system was shut down, you must restart the system. If you are using a virtual system, you must use the virtual administration software to restart the system. If you are using a physical system, you must locate the system and power it back up.
  If there are multiple network adapters on the V8.1.3 server, enter the following command to start the specific network adapter that is configured with the IP address that you are restoring to this server:
```
ip link set dev ADAPTER up
```
  Replace ADAPTER in the previous command with the adapter name from the previous step 3.a to restore the original V8.1.3 IP address to the V8.1.3 server.
The original IP address on the V8.1.4 network adapter is now restored. The V8.1.3 network adapter also has its original IP address restored.

Results

The V8.1.4 Cloud APM server becomes the new active server.