Using Infinispan 6.0.2 and a local, transactional cache backed by a <singleFile> store, with eviction enabled and a small max-entries setting, we have the following scenario:
- the main thread (i.e. the "writer") starts a transaction, adds a batch of strings into the cache and also appends the same strings into a List cache entry and then commits the transaction
- after the above has finished (i.e. after tx.commit) it fires a number of reader threads where each reader thread
- checks that the string entries were added into the cache and
- checks that the entries were correctly appended to the List entry
- the above steps are repeated a number of times
On any given run, based on timing, we're seeing that at some point (after some time) some of the reader threads will not see the latest version of the List entry (i.e. will not see the latest elements that were added into the list) but rather an old, stale List (sort of a "lost update" scenario).
If we either:
- disable eviction or
- set the max-entries to a large enough value (which I suspect has the same effect - not evicting anything) the problem doesn't show up.