Caffeine cache concurrency issues

[technical-debt-collector]

Describe the bug

We depend on Caffeine to cache some stuff. The cache is configured with a lockTimeout of 5 secs. However, it doesn't seem like the cache properly locks out concurrent attempts to access the cache (when the cached key is missing) as putting log statements in the cache method indicates it being invoked multiple times.

This causes issues further into the processing of incoming requests in our production and QA environment.
I've been able to reproduce this issue in versions 2.16.5.Final, 2.16.6.Final and 2.16.7.Final.
But I'm not sure to what lengths one should go to fix this as this issue seems to be gone in 3.1.1.Final.

Expected behavior

Only one invocation of the cached method whenever the cache key is missing

Actual behavior

If the cache key is missing, multiple invocations seem to occur in the cache method

How to Reproduce?

Reproducer can be found here: https://github.com/technical-debt-collector/quarkus-cache-repro
The project contains a scheduled method that calls a simple API which in turn will access the cache.

The issue goes away when running with Quarkus 3.1.1.Final.

One can also query the metrics and observe that the cache puts increase faster than expected

Output of uname -a or ver

Linux fedora 6.2.12-200.fc37.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Apr 20 23:38:29 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Output of java -version

openjdk version "19.0.2" 2023-01-17 OpenJDK Runtime Environment Homebrew (build 19.0.2) OpenJDK 64-Bit Server VM Homebrew (build 19.0.2, mixed mode, sharing)

GraalVM version (if different from Java)

No response

Quarkus version or git rev

2.16.7

Build tool (ie. output of mvnw --version or gradlew --version)

Maven home: /home/olasaeterheitmann/.m2/wrapper/dists/apache-maven-3.8.8-bin/67c30f74/apache-maven-3.8.8 Java version: 17.0.6, vendor: Eclipse Adoptium, runtime: /home/olasaeterheitmann/.sdkman/candidates/java/17.0.6-tem Default locale: en_US, platform encoding: UTF-8 OS name: "linux", version: "6.2.12-200.fc37.x86_64", arch: "amd64", family: "unix"

Additional information

No response

[quarkus-bot]

/cc @gwenneg (cache)

[mkouba]

But I'm not sure to what lengths one should go to fix this as this issue seems to be gone in 3.1.1.Final.

Yes, we fixed a concurrency problem in quarkus 3.0; see also my comment here.

[technical-debt-collector]

Thanks for highlighting this. I'll follow in his tracks and resolve this one. We'll most likely migrate to Quarkus 3 during the summer and can live with the issues for the time being.