CAMEL-19295 - Concurrency issues with dynamicMap in AbstractDynamicRegistry

[rhuan080]

Description

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[github-actions]

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[rhuan080]

Hi, I sent this PR and I have seen the SimpleLRUCache [1] is not thread-safe, and we don`t have a ConcurrentLinkedHashMap or something like that. Thus, I think we need to review this class to turn it thread-safe. Maybe an improvement in another issue?

[1] -

camel/core/camel-support/src/main/java/org/apache/camel/support/DefaultLRUCacheFactory.java

Line 141 in 244b828

private class SimpleLRUCache<K, V> extends LinkedHashMap<K, V> {

[github-actions]

🚫 There are (likely) no components to be tested in this PR

[davsclaus]

Yes we should look at SimpleLRUCache before 4.0, can you create a JIRA ticket

[orpiske]

Yes we should look at SimpleLRUCache before 4.0, can you create a JIRA ticket

I'm wondering if it would be possible to unify all these caches and pools that we have. For instance, we have the ServicePool which has overlapping features with the LRUCache.

[davsclaus]

Okay had to revert as this causes many other tests to fail
#10155

@rhuan080 thanks for the PR, but when changing in core, then its best to run the tests in camel-core to ensure its not affected other parts

[davsclaus]

Yes we should look at SimpleLRUCache before 4.0, can you create a JIRA ticket

I'm wondering if it would be possible to unify all these caches and pools that we have. For instance, we have the ServicePool which has overlapping features with the LRUCache.

Yeah but ServicePool is a bit complex and special for camel's producer/consumer caches.
Not really for end users. But if it can be made simpler then that would be good - its a bit tricky to maintain.

[davsclaus]

We may just drop SimpleLRUCache and use camel-caffeine-lrucache by default, and maybe move it into root/core folder. This cache is concurrent and LRU based. However it has a slight overhead on startup, that Simple does not have.

@otavioprado something you may have fun with performance testing in your lab.

[davsclaus]

I did a quick experiment with fully sync LRUCache and this unit test
#10157

It all works, but since its fully sync it may have an overhead.
To use caffeine, you can even today, just drop camel-caffeine-lrucache in the classpath and Camel uses this instead.
So end users can choose.

And we could make the simple just synchronized (but maybe slower).

@otavioprado you are welcome to test in lab

[orpiske]

@davsclaus that's a good one to test. I'll write a test for it and will do it next week. Let's see how it goes!