Relay HA
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High Availability of Relay Server in one of the two below ways
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2 or more Relay Servers read from the Source Data Sources In this case the clients connect to Relay Server via a LB. Since the requests from clients are over HTTP one of the Relay Servers or both can be serving the request based on the configuration in the LB. When one Relay goes down the other can still handle the requests. The solution is a simple one. However there will be additional load on the Network as two Relays would be reading from the same Master.
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Relay Chaining with HA using Leader Follower model
- Relay Producer reads from another Relay. This Relay can act as normal Relay for Clients.
- Relays have both producer, Source Producer and Relay Producers, bit only one is active at a time.
- On Leader Relay the source producer is active. On follower relay the relay producer is active.
- Clients can read from either relay via a LB.
- Leader/Follower election is done via Helix Leader/Follower algorithm.
- In fact we can have total of N relays with k leaders and n-k followers.
- The clients can either read from each relay via a LB or act as spectators so that they know which relay is the leader and connect to that Relay.
- This approach has not yet been implemented.
