I'm sure people have noticed this little idiosyncrasy in the way that garbage collection log output is handled in the JVM. But if you have not, this is a good data point when preparing to read through GC logs.
If you simply use the verbose:gc flag, you'll have GC log output sent to the stdout console. Now, if you use the -Xloggc:[filename] switch, the GC data will be sent to a log file which you can grep through later. But either way, you get the the same GC data ...right? Wrong.
The -Xloggc:[filename] switch has the additional effect of turning on the -XX:+PrintGCTimeStamps switch and hence gives your log files the added benefit of time stamps. Wierd! I'd expect both of these switches to have the same exact behavior. I might file an RFE or Bug on this tonight.
Oh, for those who want to use it, the -Xloggc switch was introduced in 1.4.0 and newer VMs.
If you simply use the verbose:gc flag, you'll have GC log output sent to the stdout console. Now, if you use the -Xloggc:[filename] switch, the GC data will be sent to a log file which you can grep through later. But either way, you get the the same GC data ...right? Wrong.
The -Xloggc:[filename] switch has the additional effect of turning on the -XX:+PrintGCTimeStamps switch and hence gives your log files the added benefit of time stamps. Wierd! I'd expect both of these switches to have the same exact behavior. I might file an RFE or Bug on this tonight.
Oh, for those who want to use it, the -Xloggc switch was introduced in 1.4.0 and newer VMs.
