On 01/07/17 14:57, Stephen Felts wrote: > IMO: > > 1. You should avoid `--add-modules java.se.ee' unless you need all of those > modules. You should bring in only those modules that you need. The choices > are java.activation, java.corba, java.transaction, java.xml.bind, > java.xml.ws, > java.xml.ws.annotation. So use --add-modules java.xml.ws.
Thanks for the tip. > 2. You can't use -XX:+IgnoreUnrecognizedVMOptions as a general solution > because that isn't available in JDK6 JRockit for example. Good to know. I was leaning towards JDK_JAVA_OPTIONS anyway. This point confirms that choice. > 3. Setting JDK_JAVA_OPTIONS is good because only JDK9 recognizes it and it is > inherited by all nested invocations (unless there is an exec that excludes > the environment). You might want to use > export JDK_JAVA_OPTIONS="-XX:+IgnoreUnrecognizedVMOptions --add-modules > java.xml.ws" > > 4. --add-opens is not needed starting in b175 so require that as a base. It > will still be noisy (a 3-line WARNING will be printed to the standard error). Tomcat won't officially support Java 9 until there is a GA release. Anything before then is on the basis that is should work, but it might not. Thanks again for the additional info. Mark > > > -----Original Message----- > From: Alan Bateman > Sent: Saturday, July 1, 2017 5:53 AM > To: Mark Thomas; jigsaw-dev@openjdk.java.net > Subject: Re: Cleanly starting apps on Java 9 and earlier > > On 01/07/2017 10:18, Mark Thomas wrote: >> Hi, >> >> Apache Tomcat needs to add the following options when running on Java 9: >> >> --add-modules=java.se.ee >> --add-opens=java.base/java.lang=ALL-UNNAMED >> --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED >> >> The first is because it depends on javax.xml.ws.WebServiceRef and >> javax.xml.ws.WebServiceRefs. >> We could work around this by shipping our own implementations but that >> sort of duplication should not be necessary. > The java.xml.ws module is deprecated for removal (along with the other > modules shared with Java EE) so expect these modules to not be included in > the JDK some day (exactly when is TBD as it depends on when Java SE drops > them). > > In the short term then `--add-modules java.se.ee` will resolve the EE modules > included in the JDK but it may bring complications, it all depends on whether > you have the EE java.transaction module or JAR files with annotations in the > javax.annotation package in your environment. An important page for the JDK 9 > docs is a page with instructions and deployments options for those using > these APIs. > > >> >> The second and third are required by Tomcat's memory leak detection >> and prevention code. In an ideal world, web applications wouldn't have >> memory leaks. Unfortunately, the world isn't ideal and the memory leak >> detection and prevention code has proven immensely valuable over the years. > Both of these packages are open since jdk-9+175 so the hacks to null fields > will continue to work. > > That said, I thought the issue with TCCL in sun.rmi.transport.GC was fixed > via JDK-8157570. Have you tested that? > > >> The problem we have is that Tomcat needs to run on Java 9 though 6. If >> the above options aren't provided, Java 6 through 8 are fine but on Java >> 9 at best the users see a bunch of errors and at worst Tomcat won't >> start. If the above options are included, Java 9 is fine but then Tomcat >> fails to start on Java 6 though 8. >> > The launch script could examine the JAVA_VERSION property in the > `release` file. Another approach is to set the JDK_JAVA_OPTIONS > environment variable as that is new 9 and so will be ignored by older > releases. There is also -XX:+IgnoreUnrecognizedVMOptions to ignore > unrecognized options. > > -Alan >
