Last updated 16th November 2022
Objective
If you want to move your objects from one data centre to another, or even from one project to another, syncing objects between containers is the best solution for avoiding service disruptions during your migration. This guide explains how you can implement this solution.
Requirements
- An environment that is ready to use the OpenStack API with the Swift client
- OpenStack environment variables set
- Two object containers in two different data centres
Instructions
If your container contains objects larger than 5 GB, your two containers must have the same name. In addition, the synchronisation configuration must also be applied to the container that contains the segments.
Configuring the sync
Creating a sync key
For containers to authenticate, you will need to create a key and configure it on each object container.
- Create the key:
root@server-1:~$ sharedKey=$(openssl rand -base64 32)
Destination container configuration
First of all, you will need to configure the key on the container that will receive the data. In our case, the destination container is in BHS.
- Check the region that has loaded in the environment variables:
root@server-1:~$ env | grep OS_REGION
OS_REGION_NAME=BHS
- Configure the key on the destination container:
root@server-1:~$ swift post --sync-key "$sharedKey" containerBHS
- Next, check that the key has been successfully configured using the following command, and note down the content of the "Account" variable at the same time:
root@server-1:~$ swift stat containerBHS
Account: AUTH_b3e269xxxxxxxxxxxxxxxxxxxx2b0ba29
Container: containerBHS
Objects: 0
Bytes: 0
Read ACL:
Write ACL:
Sync To:
Sync Key: 4cA5j5LyaaG2ws32d1fsdQSxnvIJv+y2qFnbnm6Kw=
Meta Access-Control-Allow-Origin: https://www.ovh.com
Accept-Ranges: bytes
X-Storage-Policy: Policy-0
Connection: close
X-Timestamp: 1444812373.28095
X-Trans-Id: B2210C05:895E_9E45A961:01BB_561E52E1_16A3:5298
Content-Type: text/plain; charset=utf-8
- Retrieve the target container’s address, then configure it on the source container (this one is: "//OVH_PUBLIC_CLOUD/Region/Account/Container").
root@server-1:~$ export destContainer="//OVH_PUBLIC_CLOUD/BHS/AUTH_b3e269xxxxxxxxxxxxxxxxxxxx2b0ba29/containerBHS"
Source container configuration
- Change the region in the environment variables:
root@server-1:~$ export OS_REGION_NAME=GRA
- Configure the key on the source container:
root@server-1:~$ swift post --sync-key "$sharedKey" containerGRA
- Configure the recipient container on the source container:
root@server-1:~$ swift post --sync-to "$destContainer" containerGRA
- As detailed previously, you can check that it has been configured properly using the following command:
root@server-1:~$ swift stat containerGRA
Account: AUTH_b3e269xxxxxxxxxxxxxxxxxxxx2b0ba29
Container: containerGRA
Objects: 3
Bytes: 15
Read ACL:
Write ACL:
Sync To: //OVH_PUBLIC_CLOUD/BHS/AUTH_b3e269xxxxxxxxxxxxxxxxxxxx2b0ba29/containerBHS
Sync Key: 4cA5j5LyaaG2wU4lDYnDmEwQSxnvIJv+y2qFnbnm6Kw=
Accept-Ranges: bytes
Connection: close
X-Timestamp: 1444813114.55493
X-Trans-Id: B2210C05:879E_052711B1:01BB_561E559B_24AE:6B1B
X-Storage-Policy: Policy-0
Content-Type: text/plain; charset=utf-8
Checking the sync
After a few minutes (depending on the number and size of the files to be sent), you can check whether the sync is successful by simply listing the files in each container.
- To list the files on the source container:
root@server-1:~$ swift list containerGRA
test1.txt
test2.txt
test3.txt
- To list the files on the destination container:
root@server-1:~$ swift list containerBHS
test1.txt
test2.txt
test3.txt
Reversing the synchronisation between two containers
In order to reverse the synchronisation between two containers, you need to remove the --sync-to metadata from the source container, and redeclare it on the other container, which will then become the new source container.
Don't forget to also change the region in the new "sync-to" URL.
root@server-1:~$ swift post -H "X-Container-Sync-To:" containerGRA
root@server-1:~$ export destContainer="//OVH_PUBLIC_CLOUD/GRA/AUTH_b3e269xxxxxxxxxxxxxxxxxxxx2b0ba29/containerGRA"
root@server-1:~$ export OS_REGION_NAME=BHS
root@server-1:~$ swift post --sync-to "$destContainer" containerBHS
Stop synchronisation between two containers
In order to stop synchronisation between two containers, you need to remove the --sync-key and --sync-to metadata:
swift post -H "X-Container-Sync-Key:" containerGRA
swift post -H "X-Container-Sync-To:" containerGRA
You can also use this guide for migrating RunAbove objects to the OVHcloud Public Cloud.
Go further
Join our community of users on https://community.ovh.com/en/.
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