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https://issues.apache.org/jira/browse/RATIS-2497?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Ivan Andika updated RATIS-2497:
-------------------------------
    Description: 
Currently the dummy request is a WATCH(0) which will trigger client leader 
failover. In a follower read client scenario, this might cause client to always 
failover to the leader which reduces the follower read effectiveness.


{code:java}
static OrderedAsync newInstance(RaftClientImpl client, RaftProperties 
properties) {
    final OrderedAsync ordered = new OrderedAsync(client, properties);
    // send a dummy watch request to establish the connection
    // TODO: this is a work around, it is better to fix the underlying RPC 
implementation
    if (RaftClientConfigKeys.Async.Experimental.sendDummyRequest(properties)) {
      ordered.send(RaftClientRequest.watchRequestType(), null, null);
    }
    return ordered;
  }
{code}


One solution implement a new noop request (some kind of ping request) which 
simply returns a successful response regardless of the Raft peer role.

However, it might be better to address the long term TODO by fixing the 
underlying RPC implementation.

  was:
Currently the dummy request is a WATCH(0) which will trigger client leader 
failover. In a follower read client scenario, this might cause client to always 
failover to the leader which reduces the follower read effectiveness.

We can try to implement a new noop request (some kind of ping request) which 
simply returns a successful response regardless of the Raft peer role.


> Implement dummy request as a noop request instead of watch request
> ------------------------------------------------------------------
>
>                 Key: RATIS-2497
>                 URL: https://issues.apache.org/jira/browse/RATIS-2497
>             Project: Ratis
>          Issue Type: Improvement
>            Reporter: Ivan Andika
>            Assignee: Ivan Andika
>            Priority: Major
>          Time Spent: 0.5h
>  Remaining Estimate: 0h
>
> Currently the dummy request is a WATCH(0) which will trigger client leader 
> failover. In a follower read client scenario, this might cause client to 
> always failover to the leader which reduces the follower read effectiveness.
> {code:java}
> static OrderedAsync newInstance(RaftClientImpl client, RaftProperties 
> properties) {
>     final OrderedAsync ordered = new OrderedAsync(client, properties);
>     // send a dummy watch request to establish the connection
>     // TODO: this is a work around, it is better to fix the underlying RPC 
> implementation
>     if (RaftClientConfigKeys.Async.Experimental.sendDummyRequest(properties)) 
> {
>       ordered.send(RaftClientRequest.watchRequestType(), null, null);
>     }
>     return ordered;
>   }
> {code}
> One solution implement a new noop request (some kind of ping request) which 
> simply returns a successful response regardless of the Raft peer role.
> However, it might be better to address the long term TODO by fixing the 
> underlying RPC implementation.



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