Thanks, Steve. I'll look in to this patch. As a temporary solution I use a log4j variable to manually set a "hostname" private field in the Appender. This solution is rather annoying, but it'll work fro now. Thanks again.
Alex On Fri, Oct 31, 2008 at 3:58 AM, Steve Loughran <[EMAIL PROTECTED]> wrote: > Alex Loddengaard wrote: > >> I'd like my log messages to display the hostname of the node that they >> were >> outputted on. Sure, this information can be grabbed from the log >> filename, >> but I would like each log message to also have the hostname. I don't >> think >> log4j provides support to include the hostname in a log, so I've tried >> programmatically inserting the hostname with the following three >> approaches. >> These are all within a log4j Appender. >> -Using exec to run "hostname" from the command line. This returns null. >> -Using InetAddress.getLocalHost().getHostName(). This returns null. >> -Using InetAddress.getLocalHost().getHostAddress(). This returns null. >> > > You sure your real/virtual hosts networking is set up right? I've seen > problems in hadoop there > https://issues.apache.org/jira/browse/HADOOP-3426 > Have a look/apply that patch and see what happens > > Each of these approaches works in an isolated test, but they all return >> null >> when in Hadoop's context. I believe I'd be able to get the hostname with >> a >> Java call to a Hadoop configuration method if I were in a Mapper or >> Reducer, >> but because I'm in a log4j Appender, I don't have access to any of >> Hadoop's >> configuration APIs. How can I get the hostname? >> > > Log4J appenders should have access to the hostname info, But you are going > to risk time and trouble if you do that in every operation; every new > process runs a risk of a 30s delay even if you cache it from then on. It is > usually a lot faster/easier just to push out the IP address, as that > doesn't trigger a reverse DNS lookup or anything. >
