Github user cestella commented on a diff in the pull request:
https://github.com/apache/metron/pull/947#discussion_r172870992
--- Diff:
metron-platform/metron-enrichment/src/main/java/org/apache/metron/enrichment/bolt/JoinBolt.java
---
@@ -89,29 +91,25 @@ public void prepare(Map map, TopologyContext
topologyContext, OutputCollector ou
if (this.maxTimeRetain == null) {
throw new IllegalStateException("maxTimeRetain must be specified");
}
- loader = new CacheLoader<String, Map<String, Tuple>>() {
- @Override
- public Map<String, Tuple> load(String key) throws Exception {
- return new HashMap<>();
- }
- };
- cache = CacheBuilder.newBuilder().maximumSize(maxCacheSize)
- .expireAfterWrite(maxTimeRetain,
TimeUnit.MINUTES).removalListener(new JoinRemoveListener())
- .build(loader);
+ loader = s -> new HashMap<>();
+ cache = Caffeine.newBuilder().maximumSize(maxCacheSize)
+ .expireAfterWrite(maxTimeRetain, TimeUnit.MINUTES)
+ .removalListener(new JoinRemoveListener())
--- End diff --
So, I believe this was intentionally done before this PR (I migrated this
to the new caching strategy) and the idea is that if a removal is happening
from the join cache under specific circumstances, we want to know about it
because a message could be being dropped because the cache is being
overwhelmed. @merrimanr Can you chime in here on the rationale?
---
