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Comment by burtonator | Hacker News Reader

We use OpenJDK 8 at Datastreamer as part of our social media and blog/news crawler.

It's pretty solid for production use. We're REALLY production as we've been in business for a decade and burn a ton of CPU indexing web content. Think petabytes... :)

The only time we use the Oracle JDK is to run their profiler which is pretty darn nice. It's runtime and sampling so you can get a nice sample in a production app by just restarting it...

I've never had a problem with an incorrect sample.

What I REALLY want though is continuous profiling where we have profiling data uploaded to the cloud and alerts when we have an app regression automatically and I want to be told WHERE the regression is. ...

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As of JDK 11, all commercial Oracle JDK features, including low-overhead profiler (Java Flight Recorder), are part of OpenJDK.[1]

[1]: https://blogs.oracle.com/java-platform-group/oracle-jdk-rele...

Yeah.. I'm really excited about that but we're not ready to move to OpenJDK 11... it's a crap shoot with the new JVMs and the forced upgrades IMO.

The difficulty isn't the new release cadence but upgrading beyond Java 9. It's not as scary as it sounds, and even large complex projects can be upgraded within hours to a couple of weeks. For most projects it's a matter of upgrading dependencies (possibly adding dependencies that have been split off of the JDK) and fixing the command line. I would say that the main barrier is if a dependency does not yet work with 9+. Most popular Java libraries do support 9+, but some don't yet and will soon (e.g. Spark).

Once you're past 9, it's smooth(ish) sailing. The new feature releases are somewhere between the old update releases and the old major releases, but much closer to the former (BTW, there was a "forced" upgrade to the old update releases, too; they weren't supported after a new one was released).

Overall, the rate of expected breakage, if any, should be the same as it was before, but happen more gradually.

(I work on OpenJDK at Oracle, but speak only for myself)

We do exactly this!

Our startup Opsian (https://www.opsian.com) is a very low overhead continuous profiling service for the JVM.

Our JVM agent sends profiling data from your instances to our cloud environment where it's indexed, aggregated and made available for hotspots/tree/flamegraph reports.

We even have a dedicated report telling you where regressions happen between releases.

(We're actually out at Devoxx 2018 right now doing a talk on why everyone should be doing continuous profiling)

This looks interesting, however I can't agree that everyone should be doing continuous profiling.

I wish I could always run a profiler continuously on production, but there are some areas where the overhead is just unacceptable (eg. low latency applications for high frequency trading).

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