10 Replies Latest reply: Nov 14, 2008 11:46 AM by 10028 RSS

    Java Can you use multiple JRE versions with discoverer plus?

    209190
      I have two Discoverer environments:

      10.1.2.2 CP4 runs best on 1.5.0_12

      10.1.2.3 runs best on 1.6.0_7

      Is it possible to run Discoverer Plus on the same machine if i need different versions of JRE? If so what do I need to do? Any thoughts?
        • 1. Re: Java Can you use multiple JRE versions with discoverer plus?
          Michael Armstrong-Smith
          Hi
          No, this is not possible. You can only have one vesrion of Java at a time and the highest version will take priority.

          You can of course have one Discoverer running on JInitiator and the other on Sun. These would not conflict. You can even have two different JInitaitors at the same time.

          By the way, the issue here is not Oracle but Sun. They are the ones with the restriction.

          If anyone has any other updates I'd be happy to hear.

          Michael
          • 2. Re: Java Can you use multiple JRE versions with discoverer plus?
            209190
            Michael,

            Thanks for your reply. I have been reading a variety of web pages talking about being able to run multiple versions of JRE and the version needed would be utilized based on the applet specification.

            Do you know of a simple problem I could look for when I open Disco Plus 10.1.2.2 CP4 with JRE 1.6.0_7? If that problem exists with just JRE 1.6.0_7 on my machine, then I'll try the multiple version recommendations, and see if it rectifies itself.

            Jamie
            • 3. Re: Java Can you use multiple JRE versions with discoverer plus?
              10028
              Hi Jamie,

              I don't know about others but my problem with 10.1.2.2 CP8 and JRE 1.6.07 is that all Discoverer Plus screens are slow to open - tends to be 1-2 minutes per screen. If I remove JRE 1.6 any version and go down to 1.5 any version or below, the screens open quickly - tends to be 1-2 seconds. As a result, we have chosen not to upgrade to 10.1.2.2.

              I have heard that 10.1.2.3 has many bugs yet. How is it working for you? It is interesting that JRE 1.6.07 is not an issue on 10.1.2.3.

              I would really like to know more about "web pages talking about being able to run multiple versions of JRE and the version needed would be utilized based on the applet specification." Do you have a url for any of these web pages? Maybe they can help me solve our issues with 10.1.2.2 and JRE 1.6.07.

              Thank you,
              Nancy
              • 4. Re: Java Can you use multiple JRE versions with discoverer plus?
                209190
                Here is my best crack at understanding how I was able to run multiple JRE versions so that Disco Plus will run with the correct version.

                For example: You have three environments that are at different release levels.

                ENV01: Discoverer 10.1.2.0 runs with JRE 1.5.0_12

                ENV02: Discoverer 10.1.2.2 CP4 runs with JRE 1.5.0_16

                ENV03: Discoverer 10.1.2.3 CP2 runs with JRE 1.6.0_7

                Install all three versions of JRE on your PC

                Modify the configuration.xml within each Discoverer environment.

                ENV01: By modifying the classid to require 1.5.0_12 it will only use that version. You may have to select through some prompts but the JVM will be set to 1.5.0_12

                <jvm name="sun"
                classid="clsid:CAFEEFAC-0015-0000-0012-ABCDEFFEDCBA"
                plugin_setup="http://discoapp.server.com/jpi/jre15012.exe"
                version="1.5"
                versionie="1,5,0,mn"
                type="application/x-java-applet"
                plugin_page="http://java.sun.com/javase/downloads/index_jdk5.jsp"
                disco_archive="disco5i.jarjar"
                d4o_archive="d4o_double.jarjar"/>

                ENV02: By modiying the classid to require 1.5 family it will use the highest version of the 1.5 family you have installed. Which is 1.5.0_16.

                <jvm name="sun"
                classid="clsid:CAFEEFAC-0015-0000-FFFF-ABCDEFFEDCBA"
                plugin_setup="http://discoapp.server.com/jpi/jre15016.exe"
                version="1.5"
                versionie="1,5,0,mn"
                type="application/x-java-applet"
                plugin_page="http://java.sun.com/javase/downloads/index_jdk5.jsp"
                disco_archive="disco5i.jarjar"
                d4o_archive="d4o_double.jarjar"/>

                ENV03: By modiying the classid to require 1.6 family it will use the highest version of the 1.6 family you have installed. Which is 1.6.0_7.

                <jvm name="sun"
                classid="clsid:CAFEEFAC-0016-0000-FFFF-ABCDEFFEDCBA"
                plugin_setup="http://discoapp.server.com/jpi/jre1607.exe"
                version="1.6"
                versionie="1,6,0,mn"
                type="application/x-java-applet"
                plugin_page="http://java.sun.com/javase/downloads/index_jdk6.jsp"
                disco_archive="disco5i.jarjar"
                d4o_archive="d4o_double.jarjar"/>


                Again folks, this is only my attempt. I am still testing and trying to fully understand how it all works. I'm not java expert. Please feel free to comment if you like.

                Jamie
                • 5. Re: Java Can you use multiple JRE versions with discoverer plus?
                  209190
                  Nancy,

                  You might want to experiment with using 1.6.0_10. It seems that the latest release allows you to manage what JRE versions you want available on your PC. During my latest testing I installed all 1.5 versions and 1.6 versions. After setting the classid for my environment to family I simply just disable/enable the higher versions of that family using Java Console.

                  I have not been able to confirm if there are any issues with 1.6.0_10 installed on my PC yet.

                  Jamie
                  • 6. Re: Java Can you use multiple JRE versions with discoverer plus?
                    10028
                    Hi Jamie,

                    I tried the 1.6.10 version and performance was still horrible. I didn't realize there was something that could be done regarding designating the version of JRE to be used by PC. This could be a maintenance issue since we have about 1000 users worldwide but I'll have to check into it.

                    Thanks,
                    Nancy
                    • 7. Re: Java Can you use multiple JRE versions with discoverer plus?
                      Jacob Madsen
                      Regarding performance issues with 1.6.0_10: I have just recently found a solution to a similar issue after researching these problems for a long time together with a support analyst at Oracle Support. The solution we found have been documented in details in MetaLink Note 747189.1.

                      To sum up the solution short: If you are using Discoverer with 1.6.0_03 or later, including 1.6.0_10, you need to make sure, that the external IP of your Discoverer server has a reverse DNS entry. This means:

                      nslookup <IP address> must resolve to the <machinename.domainname>

                      and

                      nslookup <machinename.domainname> must resolve to <IP address>

                      After asking our ISP to implement a reverse DNS entry for our external IP address for the Discoverer server, this problem was solved, and we can now use any 1.6.0_xx version, and it runs with speed equal to 1.5.0_xx. My contact at Oracle Support has also confirmed, that doing so has solved the exact same problem for other costumers, with who she was working with simultaneously with me.

                      Hope this helps anyone still having performance problems with 1.6.0_10.

                      Regards,
                      Jacob
                      • 8. Re: Java Can you use multiple JRE versions with discoverer plus?
                        10028
                        Hi Jacob,

                        AWESOME! Now, to see if it works in my environment. I have my DBA checking it out.

                        Thank you for the post! It is truly appreciated!

                        Nancy
                        • 9. Re: Java Can you use multiple JRE versions with discoverer plus?
                          Jacob Madsen
                          Hi Nancy

                          I'm happy to be able to help :) I didn't spend weeks researching this for nothing then...

                          Just as a minor follow-up: I'd just like to hear, if you managed to get reverse DNS configured for your Discoverer server, and whether it has solved your performance issues? This also goes for anyone else having similar issues.

                          Regards,
                          Jacob
                          • 10. Re: Java Can you use multiple JRE versions with discoverer plus?
                            10028
                            Hi Jacob,

                            Yes, we got it to work and it did fix our performance problems. Thank you very much for posting this fix! I had told my management that we could not move forward with the 10.1.2.2 upgrade due to this issue. This fix allowed me to change my mind and recommend that we move forward after all. I'm still waiting to hear their decision.

                            THANK YOU!
                            Nancy