[CURATOR-570] Excessive calls to ZooKeeper.updateServerList (which can result in session death)

On suspend and reconnect, Curator calls ZooKeeper.updateServerList via ConnectionState.checkState --> ConnectionState.handleNewConnectionString.  In addition, recipes may be triggered by this as well, and they too make calls ZooKeeper.updateServerList via ConnectState.checkTimeouts --> ConnectionState.handleNewConnectionString.

This happens even though the connection string has not actually changed.

Due to ZOOKEEPER-3825, this can cause the connection to be closed immediately.  On its own this would be perceived as a glitch.  But due to the Curator-induced calls, what we see is a cycle of SUSPENDED/RECONNECTED, until eventually the session dies and a new session is recreated.

Based on the source code (at time of writing), ZooKeeper.updateServerList is not intended to be called frequently like this.

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Originally reported by ryarran, imported from: Excessive calls to ZooKeeper.updateServerList (which can result in session death)

• status: Open
  
• priority: Major
  
• resolution: Unresolved
  
• imported: 2025-01-21