[IGNITE-13292] Remove unneeded ZkPinger from ZookeeperDiscovery

• Type: Improvement
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 2.9
• Fix Version/s: 2.10
• Component/s: zookeeper
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Ivan Daschinsky
• Reporter: Ivan Daschinsky
• Created: 23/Jul/20 09:58
• Updated: 07/Aug/20 10:52
• Resolved: 07/Aug/20 10:52

Description

We need remove uneeded ZkPinger from our codebase, introduced in IGNITE-9683.

This pinger was introduced to solve issues with server nodes segmentation when cluster is deactivated. The main reason of that is the strange all thread freeze when huge amount of memory is deallocated with Unsafe.freeMemory, such freeze can last for a minute and more. So this pinger doesn't solve problem at all and this is proved. The working solution to this problem is introduced in IGNITE-9658

So we should remove this code from our codebase.

Issue Links

• relates to: IGNITE-9658 Add ability to disable memory deallocation on deactivation.
• relates to: IGNITE-9683 Create manual pinger for ZK client
• links to: GitHub Pull Request #8081