[ZOOKEEPER-1855] calls to zoo_set_server() fail to flush outstanding request queue.

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: c client
• Assignee: Unassigned
• Reporter: Dutch T. Meyer
• Created: 02/Jan/14 23:07
• Updated: 03/Feb/22 08:50

Description

If one calls zoo_set_servers to update with a new server list that does not contain the currently connected server, the client will disconnect. Fair enough, but any outstanding requests on the set_requests queue aren't completed, so the next completed request from the new server can fail with an out-of-order XID error.

The disconnect occurs in update_addrs(), when a reconfig is necessary, though it's not quite as easy as just calling cleanup_bufs there, because you could then race the call to dequeue_completion in zookeeper_process and pull NULL entries for a recently completed request

I don't have a patch for this right now, but I do have a simple repro I can post when time permits.