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Regarding the Java Upgrade in Nodes


Regarding the Java Upgrade in Nodes


Hello everyone,


I have few question on regarding the java upgrade in datanodes. 


Current about my cluster Information: (Total 7 nodes cluster)


Version: Cloudera Enterprise 5.9.1 (CDH 5.9.1, Parcels)

Java VM Name: Java HotSpot(TM) 64-Bit Server VM

Java VM Vendor: Oracle Corporation

Java Version: 1.7.0_67


i have upgraded only Namenodes, (NN01, NN02)

$ java -version
java version "1.8.0_171"
Java(TM) SE Runtime Environment (build 1.8.0_171-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.171-b11, mixed mode)




1) I have upgrade Java only for namenodes, after the upgrade i'm getting the concering health of NodeManager? Like DNS Resolution, Web server status, RPC Latency Error:


RPC Latency:

The moving average of the RPC latency was 10.8 second(s) ms over the previous 5 minute(s). The moving average of the queue time was 0 second(s) ms. The moving average of the processing time was 10.8 second(s) ms. Critical threshold: 5 second(s).


DNS Resolution:

The hostname and canonical name for this host are consistent when checked from a Java process. The most recent DNS resolution took 13.2 second(s). Warning threshold: 1 second(s).


Web Server Status:

The web server of this role was responding with metrics. The most recent collection took 15.6 second(s). Warning threshold: 10 second(s).


Please Help me with this issue?


Thanks & Regards,



Re: Regarding the Java Upgrade in Nodes

Expert Contributor

hi Krishna,

rolling upgrade of Java is not supported according to

Cloudera does not support a rolling upgrade to JDK 1.8. You must shut down the entire cluster.

You should either upgrade all nodes to Java 8, or downgrade to Java 7.


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