Adding a region in a multi-region object deployment

Perform the following steps to add a region in a multi-region object deployment environment.

In the command examples, Europe is the first region and Asia is the second region.

Export the information of the first region to a file by using the mmobj multiregion export command.
For example:
```
[europe]# mmobj multiregion export --region-file /tmp/multiregion_europe.dat
```
Copy the file manually to the second region.
For example:
```
[europe]# scp /tmp/multiregion_europe.dat asia:/tmp
```
From the second region, join the multi-region environment as follows:
1. Use the file generated in the first region while deploying object on the second region by using the mmobj swift base command.
  For example:
```
[asia]# mmobj swift base -g /mnt/gpfs0 --cluster-hostname gpfs-asia --admin-password Passw0rd
-i 100000 --admin-user admin --enable-s3 \
  --enable-multi-region  --remote-keystone-url  http://gpfs-asia:35357/v3
 --join-region-file /tmp/multiregion_europe.dat \
        --region-number 2 --configure-remote-keystone
```
  This step installs the object protocol in the 2nd region and joins the 1st region. Additional devices are added to the primary ring files for this region.

Export the ring file data of the second region.

For example:

[asia]# mmobj multiregion export --region-file /tmp/multiregion_asia.dat

Copy the file manually to the first region.
For example:
```
[asia]# scp /tmp/multiregion_asia.dat europe:/tmp
```
In the first region, update the local ring files with the configuration of the second region.
For example:
```
[europe]# mmobj multiregion import --region-file /tmp/multiregion_asia.dat
```
This step reads in the ring files which are updated with the information of the second region. This update ensures that the data of the second region contains a new region and therefore replaces the associated ring files in the first region with the ones from the second region.

Note:

Now the two clusters have been synced together and can be used as a multi-region cluster. Objects can be uploaded and downloaded from either region. If the installation of the second region specified the --configure-remote-keystone flag, a region-specific endpoint for the object-store service for the 2nd region is created in Keystone.

The regions need to be synced in the future any time region-related information changes. This includes changes in the set of CES IP addresses (added or removed) or if storage policies were created or deleted within a region. Changes that affect the swift.conf file or ring files need to be synced to all regions. For example, adding additional CES addresses to a region causes the ring files to be rebuilt.

In the second region, add CES addresses and update other clusters.
For example:
```
[asia]# mmces address add --ces-ip asia9
```
This steps adds an address to the CES IP pool. This also triggers a ring rebuild which changes the IP-to-device mapping in the ring files.
Export the ring data so the other clusters in the region can be updated with the new IPs from the second region.
For example:
```
[asia]# mmobj multiregion export --region-file /tmp/multiregion_asia.dat
```
Copy the file manually to the first region.
For example:
```
[asia]# scp /tmp/multiregion_asia.dat europe:/tmp
```
In the first region, update with changes for the new second region address in the ring.
For example:
```
[europe]# mmobj multiregion import --region-file /tmp/multiregion_asia.dat
```
This step imports the changes from the second region. When this is complete, a checksum is displayed which can be used to determine when regions are synchronized together. By comparing it to the one printed when the region data was exported, you can determine that the regions are synchronized when they match. In some cases, the checksums do not match after import. This is typically due to some local configuration changes on this cluster which are not yet synced to the other regions. If the checksums do not match, then this region's configuration needs to be exported and imported into the other region to sync them.