[IGNITE-13495] ZookeeperDiscoverySpiMBeanImpl#getCoordinator can return invalid node as coordinator

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.9
• Fix Version/s: 2.10, 2.9.1
• Labels: 2.9.1-rc newbie zookeeper
• Assignee: Sergei Ryzhov
• Reporter: Ivan Daschinsky
• Created: 29/Sep/20 08:22
• Updated: 03/Nov/20 15:09
• Resolved: 05/Oct/20 12:26

Description

Due to invalid algorithm in org.apache.ignite.spi.discovery.zk.internal.ZookeeperDiscoveryImpl#getCoordinator
sometimes invalid coordinator could be returned

Consider scenarion:
1. Start server #1
2. Start client
3. Start server #2
4. Stop server #1

After this, ZookeeperDiscoverySpiMBeanImpl#getCoordinator returns as coordinator a client, because it is the oldest node in topology.

We should fix org.apache.ignite.spi.discovery.zk.internal.ZookeeperDiscoveryImpl#getCoordinator to return oldest server, not any node.

Issue Links

• links to: GitHub Pull Request #8313