Details
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New Feature
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Status: Resolved
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Major
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Resolution: Duplicate
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Description
For HiveServer2 HA use cases with LLAP, launching a new Tez session (AM) after failover adds non-interactive latency. Additionally, Tez with LLAP does significant work to provision a long-lived session and hold on to necessary resources allocated to it. We don't want to redo that work after failover and potentially be unable to schedule equivalent resources that may be taken by other applications during failover.
HS2 uses TezClient for creating sessions. To simplify HS2 failover to an existing Tez AM, add a "reconnect" method to TezClient.
public void reconnect(ApplicationId) { ... }
reconnect will setup the TezClient context very similar to start except it parameterizes the sessionAppId and doesn't launch a new AM.