SSL session cache default maximum number of entries

[Hohensee, Paul]

The default value for the maximum number of entries in the SSL session cache (which is a SoftReference cache) is infinite, and the entry timeout is 24 hours. With larger heaps, we’re running into situations where the cache ends up with several million entries when the 24 hours are up. They’re then all invalidated at the same time, resulting in multi-minute pauses (effectively service failures). We’ve experimented with using 10k as the default maximum number of entries with good results (i.e., no latency increases due to sessions falling out of the cache). It’s late and a long shot for JDK11: we’d love to see it changed there because 11 is an LTS release and this is, at least nominally, a behavior change which might not be acceptable in 11u. What do people think?

Thanks,

Paul