Summary

100% CPU usage on a specific node in DataStax Enterprise

Applies to

• DataStax Enterprise (DSE) 6.0 and above.

Symptoms

• While checking the CPU usage of a specific node, a constant CPU usage of 100% was observed
• The following error can also be seen repeating constantly on the faulty node:

1234567891011ERROR [CoreThread-1] 2018-09-14 07:45:16,397 EpollTPCEventLoopGroup.java:730 - Task exception encountered: 
java.lang.RuntimeException: Failed to process class org.apache.cassandra.db.ReadResponse$LocalResponse$$Lambda$850/425059782 
at org.apache.cassandra.utils.LineNumberInference.maybeProcessClassInternal(LineNumberInference.java:229) 
Caused by: java.io.FileNotFoundException: /tmp/dse/dse.FKb2MavbG/lni/org/apache/cassandra/db/ReadResponse$LocalResponse$$Lambda$850.class (No such file or directory) 
at java.io.FileInputStream.open0(Native Method) 
at java.io.FileInputStream.open(FileInputStream.java:195) 
at java.io.FileInputStream.<init>(FileInputStream.java:138) 
at java.io.FileInputStream.<init>(FileInputStream.java:93) 
at org.apache.cassandra.utils.LineNumberInference.maybeProcessClassInternal(LineNumberInference.java:206) 
... 59 common frames omitted 
ERROR [CoreThread-1] 2018-09-14 07:45:16,397 CassandraDaemon.java:117 - Exception in thread Thread[CoreThread-1,10,main]

Cause

An issue was identified in the `LineNumberInference` class

Workaround

The issue was observed only once and a restart of the node resolved the issue. If the symptoms match, attempt a restart of the node to see if that resolves the issue.

Solution

This issue is referenced under DB-2568 and the fix was delivered in DSE 6.0.5 and DSE 6.7.0.