[GEODE-2727] optimize new 1.8 ConcurrentMap default methods on Region

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: regions
• Labels: region_interface storage_2
• Assignee: Unassigned
• Reporter: Darrel Schneider
• Created: 29/Mar/17 00:21
• Updated: 21/Jun/18 16:12

Description

In JDK 1.8 ConcurrentMap added the following default methods to the interface:

getOrDefault
computeIfAbsent
computeIfPresent
compute
merge
foreach
replaceAll

All of the default implementations of these methods have issues with get returning null when the key actually exists. So they do not support invalidated region entries.
The other problem with all of them (except getOrDefault) is that they will make multiple round trips when done from a proxy. In a distributed environment we should implement these to send the lambda to the primary so that the entire operation can be done with one message and while the RegionEntry is locked.
This would require that the lambda parameter by serializable which would be consistent with what we do for other parameters to Region methods (for example "put").
From a performance point of view "foreach" and "replaceAll" are the worst since they bring back to whoever is executing the method all the keys and values from the entire cluster.
It is also worth considering how the operations behave in a geode transaction.