[MESOS-5396] After failover, master does not remove agents with same UPID.

• Type: Improvement
• Status: Accepted
• Priority: Minor
• Resolution: Unresolved
• Component/s: master
• Labels: foundations mesosphere
• Epic Link: Mesos Agent Lifecycle
• Assignee: Unassigned
• Reporter: Neil Conway
• Shepherd: Vinod Kone
• Created: 17/May/16 16:03
• Updated: 25/Feb/19 23:35

Description

Scenario:

• master fails over
• an agent host is restarted; the agent attempts to register (not reregister) with Mesos using the same UPID as the previous agent instance; this means it will get a new agent ID
• framework isn't notified about the status of the tasks on the old agentID until the agent_reregister_timeout expires (10 mins)

This isn't necessarily wrong but it is suboptimal: when the agent attempts to register with the same UPID that was used by the previous agent instance, we know that a reregistration attempt for the old <UPID, agentID> pair will never be seen. Hence we can declare the old agentID to be gone-forever and notify frameworks appropriately, without waiting for the full agent_reregister_timeout to expire.

Note that we already implement the proposed behavior for the case when the master does not failover (https://github.com/apache/mesos/blob/0.28.1/src/master/master.cpp#L4162-L4172).

Issue Links

• is related to: MESOS-4048 Consider unifying slave timeout behavior between steady state and master failover
• is superceded by: MESOS-6223 Allow agents to re-register post a host reboot