Difference between Eviction, Expire and Remove events

[lonix1]

I read the events document, but am unsure of the difference between:

• Eviction
• Expire
• Remove

How do they differ? (I'm using the memory option only.)

[lonix1]

After rereading https://github.com/ZiggyCreatures/FusionCache/blob/main/docs/CoreMethods.md, I think:

• Eviction: raised after a cache entry is evicted by the library itself (after the entry's TTL expires); there is no "EvictAsync" method, this is an internal mechanism only
• Expire: raised after a cache entry is evicted by user code (via ExpireAsync)
• Remove: raised after a cache entry is evicted by user code (via RemoveAsync)

Is my understanding correct?

[jodydonetti]

Yes, basically "eviction" is in general what happens when an entry in the cache "goes away".

Remove does remove an entry from the cache, for good (there's no going back).

Expire instead means "remove the entry if fail-safe is off for that entry, otherwise mark it as expired but keep it around in case it's needed as a fallback" (see fail-safe for more).

Hope this helps.

[lonix1]

Thanks.

Just to be 100% sure I understand the events themselves... When I call ExpireAsync it will raise the Expire event, when I call RemoveAsync it will raise the Remove event, and when the cache itself evicts an entry it will raise the Eviction event (which cannot be manually triggered).

Those events are only raised in those circumstances? Is that correct?

[jodydonetti]

Just to be 100% sure I understand the events themselves... When I call ExpireAsync it will raise the Expire event, when I call RemoveAsync it will raise the Remove event

Correct!

and when the cache itself evicts an entry it will raise the Eviction event (which cannot be manually triggered).

When the memory cache itself internally evicts an entry, that triggers the Eviction event (I have no control over it, it happens when it happens).

[lonix1]

Thanks, that's what I thought, but I just wanted to be sure - because we are using the library in a complicated setup and I need to monitor when specific things happen.

I'm going through the v2 bits now, amazing how much work went into that... And you even beat Microsoft's "brain trust" to release the implementation. Congratulazioni! 👍

[jodydonetti]

I'm going through the v2 bits now, amazing how much work went into that...

Thanks, that's really appreciated!
And allow me a little "proud corner" here: get out with v2 yes that has been a mega crunch... the amount of stuff and the complexity to get Tagging to work, work well, in all the edge cases, with the various specific optimizations and all the rest (including being able to get a O(1) perf on RemvoeByTag() execution, independently from the number of affected entries) has been both super demanding and honestly one of the highest point of my career.
/end of proud corner.

And you even beat Microsoft's "brain trust" to release the implementation. Congratulazioni! 👍

Ahah thanks, that has been the cherry on top 😅