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SUSE Manager Server performance issues caused by "java tomcat" process

This document (000020386) is provided subject to the disclaimer at the end of this document.


SUSE Manager 4.1 Server
SUSE Manager 4.2 Server


SUSE Manager Server is randomly slow, it is not answering calls and getting stuck. When such issue occurs "java tomcat" process consumes most of the CPU-Time. Following error messages can be observed within rhn_web_ui.log file: 
2021-09-13 09:45:44,110 [pool-1-thread-1] ERROR org.apache.http.impl.nio.client.InternalHttpAsyncClient - I/O reactor terminated abnormally
org.apache.http.nio.reactor.IOReactorException: I/O dispatch worker terminated abnormally
        at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor.execute(
        at org.apache.http.impl.nio.conn.PoolingNHttpClientConnectionManager.execute(
        at org.apache.http.impl.nio.client.CloseableHttpAsyncClientBase$
        at java.base/
Caused by: java.lang.OutOfMemoryError: Java heap space  


Based on the error messages, the culprit is out of memory error. OOM condition stopped the I/O reactor which then lead to the errors and the slowness of the system is the result of that. In order to fix such issue, it helps to increase Tomcat max heap memory limit (which is usually set to default 1G):

1. On top of SUSE Manager Server, in `/etc/sysconfig/tomcat` please double (if that does not help triple) the value for `-Xmx1G` parameter so it looks like:

JAVA_OPTS="…​ -Xmx2G …​"

2. Restart spacewalk-service

spacewalk-service restart
For more details, please check following link .


Insufficient max heap memory limit for Tomcat process. Such behavior can occur in large deployments.


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  • Document ID:000020386
  • Creation Date: 15-Sep-2021
  • Modified Date:15-Sep-2021
    • SUSE Manager Server

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