[LOG4J2-3602] Don't output ERROR level stacktrace in getLogger() call when there is no network available

• Type: Improvement
• Status: Open
• Priority: Trivial
• Resolution: Unresolved
• Affects Version/s: 2.17.1, 2.17.2
• Component/s: Core

Environment

In this case software was running in a docker container with localhost `–network none` set.  

• Assignee: Unassigned
• Reporter: Louis Bergelson
• Created: 19/Sep/22 21:34
• Updated: 20/Sep/22 19:41

Description

If there is no network adaptor trying to get a new logger using `LogManager.getLogger()` results in an ERROR level log message with a full stacktrace. This seems unintentional and undesirable.

Here's an example of the output:

ERROR Could not determine local host name java.net.UnknownHostException: de2c81c88ddc: de2c81c88ddc: Temporary failure in name resolution
at java.net.InetAddress.getLocalHost(InetAddress.java:1506)
at org.apache.logging.log4j.core.util.NetUtils.getLocalHostname(NetUtils.java:54)
at org.apache.logging.log4j.core.LoggerContext.lambda$setConfiguration$0(LoggerContext.java:620)
at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660)
at org.apache.logging.log4j.core.LoggerContext.setConfiguration(LoggerContext.java:620)
at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:699)
at org.apache.logging.log4j.core.LoggerContext.reconfigure(LoggerContext.java:716)
at org.apache.logging.log4j.core.LoggerContext.start(LoggerContext.java:270)
at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:155)
at org.apache.logging.log4j.core.impl.Log4jContextFactory.getContext(Log4jContextFactory.java:47)
at org.apache.logging.log4j.LogManager.getContext(LogManager.java:196)
at org.apache.logging.log4j.LogManager.getLogger(LogManager.java:599)
at org.broadinstitute.hellbender.utils.Utils.<clinit>(Utils.java:72)
at org.broadinstitute.hellbender.Main.<clinit>(Main.java:45)
Caused by: java.net.UnknownHostException: de2c81c88ddc: Temporary failure in name resolution
at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:929)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1324)
at java.net.InetAddress.getLocalHost(InetAddress.java:1501)
...13 more

 

 I believe this is unintentional because the associated code has a general catch for all potential exceptions which logs a DEBUG level message in case of failure.  However the call to `NetUtils.getLocalHostname()` actually does it's own error handling and very verbose logging.

 

The relevant call is here at LoggerContext.java line 613

try {
    map.computeIfAbsent("hostName", s -> NetUtils.getLocalHostname());
} catch (final Exception ex) {
    LOGGER.debug("Ignoring {}, setting hostName to 'unknown'", ex.toString());
    map.putIfAbsent("hostName", "unknown");
}

 

The problematic logging statement is in NetUtils.getLocalHostname() line 77:

 

} catch (final UnknownHostException uhe) {

  ...

   LOGGER.error("Could not determine local host name", uhe);
   return UNKNOWN_LOCALHOST;
}

Issue Links

• is related to: LOG4J2-3442 Defer hostname lookup until first used