By Terry Goss, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1561215
Things that go wrong when deploying Java with containers
Martin Lehmann
@theneva
FINN.no
(and how to avoid them)
Get to know your app!
- ~1000 req/s @ peak traffic
- 6M unique visitors / week
- App config confined to app repo
- Easier to start apps locally and in CI
- Higher dev/production parity
- Automatic horisontal scaling
- Overall improved performance at much lower cost
A tale of CPU and memory
OOMKilled!
- Memory request = 1G
- Memory limit = 1,3G
- Max heap size = 0,6 * Limit = 0,78
Hystrix <3 72 CPUs
Java >= 8u131
(April 2017)
-
-XX:+UnlockExperimentalVMOptions
-
-XX:+UseCGroupMemoryLimitForHeap
By Chagai at English Wikipedia - Transferred from en.wikipedia to Commons., Public Domain, https://commons.wikimedia.org/w/index.php?curid=3839230
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By maix - Based on blank map of Europe.svg, source: Time zones of Europe.png;, CC SA 1.0, https://commons.wikimedia.org/w/index.php?curid=1641488
- UTC is great!
- Except when locales aren't configured
What can we do?
Know your app before you run it!
- (How) do you need to tune the JVM?
- Do you have anything that scales by CPUs?
- Which resources does your app really need?
- Make it easy to do the right thing!
Help your developers!
FROM <container registry>/finntech/java8:8
ENV LC_ALL "no_NB.UTF-8"
ENV LANG "no_NB.UTF-8"
ENV TZ "Europe/Oslo"
ENV JAVA_OPTS -DLog4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector
COPY build/libs/ad-input-server-*.war /app
So: avoid great white sharks by…
- Knowing your app's requirements and dependencies!
- Making it easy to do the right thing
- Expecting failure, and enabling easy rollback
Come talk to us!
Things that go wrong when deploying Java with containers (and how to avoid them)
By theneva
Things that go wrong when deploying Java with containers (and how to avoid them)
60-ish minute talk for JavaZone Oslo 2017
