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talino2321 avatar image
talino2321 asked Erick Ramirez commented

Why can't I get OpsCenter to start for DS210? Getting "Detected Java version 11.0.7"

following the lab exercise for DS210 Lab Exercise (OpsCenter). It appears to properly install the opscenter via apt-get (O/S is Ubuntu 18.04 LTS with jdk v. 11.0.7). after changes to the opscenter.conf to put in my external ip address. I run 'sudo service opscenterd start' . I check the status of the service and see the following

root@ds210-node3:/etc/opscenter# sudo service opscenterd status
● opscenterd.service - LSB: Cassandra cluster manager
Loaded: loaded (/etc/init.d/opscenterd; generated)
Active: active (exited) since Wed 2020-07-22 01:57:59 UTC; 2s ago
Docs: man:systemd-sysv-generator(8)
Process: 5307 ExecStop=/etc/init.d/opscenterd stop (code=exited, status=0/SUCCESS)
Process: 5378 ExecStart=/etc/init.d/opscenterd start (code=exited, status=0/SUCCESS)

Jul 22 01:57:58 ds210-node3 systemd[1]: Starting LSB: Cassandra cluster manager...
Jul 22 01:57:59 ds210-node3 opscenterd[5378]: Detected Java version 11.0.7
Jul 22 01:57:59 ds210-node3 systemd[1]: Started LSB: Cassandra cluster manager.

I suspect it maybe the jdk version. But accordingly that version is the correct version for Ubuntu 18.04.

Any ideas on how to get it running?

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Erick Ramirez answered

OpsCenter only supports Java 8. Java 11 isn't a supported version.

I recommend you install OpenJDK 8. The high-level steps on Ubuntu are:

Step 1 - Update the repositories:

$ sudo apt-get update

Step 2 - Install OpenJDK 8:

$ sudo apt-get install openjdk-8-jdk

It might also be necessary to force a switch to Java 8. For example:

$ sudo update-alternatives --set java /usr/lib/jvm/jdk1.8.0_242/bin/java

For details of all the required steps, see Installing Open JDK 8 on Debian or Ubuntu Systems. Cheers!

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talino2321 answered Erick Ramirez commented

Thanks for the idea on how to get it running. I took what you provided, and with a little creative effort got it running. Here is what I had to do to actually get it running.

  1. remove all of the openjdks -- sudo apt-get purge --auto-remove openjdk*
  2. remove the opscenter -- sudo apt-get purge --auto-remove opscenter
  3. install openjdk 8 -- sudo apt-get install openjdk-8-jdk
  4. install opscenter -- sudo apt-get install opscenter
  5. edit the opscenter.conf to put my external ip addr in -- sudo vi /etc/opscenter/opscenterd.conf
  6. start the service -- sudo service opscenterd start

I tried just adding the openjdk-8 but apparently during the original install of opscenter, it linked to the jdk-11 path. So I was still getting the same issue even after running the sudo update-java-alternatives --set /usr/lib/jvm/java-1.8.0-openjdk-amd64 command. I might of gotten around that by removing opscenter and reinstalling, but reading some other responses in various forums about mix jdk versions causing problems, most recommended only having a single version installed.

I do have a major concern that opscenter is still on jdk 8. Datastax really needs to get it running on 11 or newer.


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Good to hear you got it running.

And thanks for the feedback about Java 11 not being supported. This is unfortunately not in our control. DSE has dependencies on third-party software which do not support Java 11. To top it off, Java 11 support is still experimental in Cassandra (CASSANDRA-9608). Cheers!

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