Extending CLAN connectivity across two or more FlashGrid clusters
Extending CLAN connectivity across two or more clusters may be needed in certain deployment scenarios where transparent layer 2 connectivity between the clusters is required. A typical scenario is for data replication (GoldenGate, SharePlex, DBvisit) using HA VIP for the replication service failover between cluster nodes. In such scenarios the connectivity is required only on the fg-pub (192.168.1.X) virtual subnet.
To extend CLAN across two or more clusters:
- Before deploying clusters that need to have CLAN extended between them, add and customize the parameters below in the cluster configuration files (used by FlashGrid Launcher or its REST API). The IP addresses must be non-overlapping between all clusters. Additionally, different sets of hostnames must be used in different clusters.
[clan] first_node_id = 11 # Recommended values are 11, 21, 31,… With default settings the node IPs will start from 192.168.1.1 first_vip = 111 # Recommended values are 111, 121, 131,… With default settings the VIP addresses will be 192.168.1.11, 192.168.1.12, 192.168.1.13 scans = [211, 212, 213] # Recommended values are [211, 212, 213], [221, 222, 223], [231, 232, 233] ,… With default settings the SCAN VIP addresses will be 192.168.1.21, 192.168.1.22, 192.168.1.23
Deploy all clusters.
The clusters must be on the same VPC/VNet or have connection between the VPCs/VNets through peering or VPN.
The clusters must have IP communication between them open on UDP port 4801 (used for fg-pub subnet).
- Different sets of hostnames must be used in different clusters.
Create a new
hostsfile and place it as
/etc/hostson each node of each cluster, including quorum nodes. The file must contain a record for each node of each cluster in the following format:
<Host VPC IP> <hostname>-ext.<domainname> <hostname>-ext
Create and deploy a new shared CLAN cfg file:
a. Copy nodes values from /etc/flashgrid-clan.cfg file of each cluster and merge the nodes values together. The resulting nodes value must be a list of all nodes of all c clusters.
b. Create a new flashgrid-clan.cfg file by taking /etc/flashgrid-clan.cfg file from any cluster and replacing the nodes value with the merged value.
c. Place the new file as /etc/flashgrid-clan.cfg on each node of each cluster, including quorum nodes.
d. Deploy the new configuration. On each node of each cluster run
sudo flashgrid-clan-cfg deploy-config-local; sudo systemctl restart flashgrid-clan.service
- Verify that the clusters are now connected. From each node of each cluster run ping to each node of each other cluster using 192.168.1.X IP addresses.