Zookeeper CDCR

The following article will present a step-by-step procedure for configuring Zookeeper Cross DataCenter Replication for an already configured CDCR deployment.

1) Generate the archive

In order to configure another datacenter to work with the same CA certificate, an archive containing all the mandatory configs must be generated.

The archive will contain the following:

HaProxy configuration file and domain certificate
FreeRadius configuration files and certificates
A file containing the IP addresses of Webapp and Persistence nodes from both datacenters and the datacenter names
Zookeeper configuration files from the primary datacenter

To generate the CDCR archive, run the following command as root user on one of the Webapp nodes from the primary datacenter:

CODE

bash /etc/veridiumid/scripts/veridiumid_cdcr.sh -g

After the operation has finished the following archive will be present in the current directory: DC1.tar.gz

Make sure to copy the archive generated to all Persistence nodes in both datacenters and to all webapp nodes in the secondary datacenter.

During the next steps of the procedure we will use ${ARCH_PATH} as the full path to the CDCR archive.

2) Zookeeper configuration

During this step, the script will create a large cluster containing the Zookeeper nodes in both datacenters.

Connect to all persistence nodes in the primary datacenter and run the following command as root, one by one:

CODE

bash /etc/veridiumid/scripts/veridiumid_cdcr.sh -z -a ${ARCH_PATH}

Connect to all persistence nodes in the secondary datacenter and run the following command as root, one by one:

CODE

bash /etc/veridiumid/scripts/veridiumid_cdcr.sh -z -s -a ${ARCH_PATH}

3) Zookeeper json sync

In order to add all nodes in the connection pools (config.json, elasticsearch.json) the following command must be run on a single node in one datacenter as root:

CODE

bash /etc/veridiumid/scripts/veridiumid_cdcr.sh -j -a ${ARCH_PATH}

4) Zookeeper.properties sync

Connect to all nodes in the secondary datacenter and run the following command as root, one by one (this is changing the salt and password taken from DC1):

CODE

bash /etc/veridiumid/scripts/veridiumid_cdcr.sh -p -r -a ${ARCH_PATH}