LogManager.getLogger doesn't work

We randomly get the following:

java.util.ConcurrentModificationException
at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:377)
at org.apache.logging.log4j.core.config.ConfigurationFactory$Factory.getConfiguration(ConfigurationFactory.java:361)
at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:266)
at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:134)
at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:75)
at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:30)
at org.apache.logging.log4j.LogManager.getLogger(LogManager.java:165)
at org.apache.logging.log4j.LogManager.getLogger(LogManager.java:174)
at …

factories is defined as:

private static List<ConfigurationFactory> factories = new ArrayList<ConfigurationFactory>();

The simple fix is to use a java.util.concurrent.CopyOnWriteArrayList:

private static final List<ConfigurationFactory> factories = new CopyOnWriteArrayList<ConfigurationFactory>();

https://svn.apache.org/repos/asf/logging/log4j/log4j2/trunk/core/src/main/java/org/apache/logging/log4j/core/config/ConfigurationFactory.java