We have been asked by several developers if we could include some optional information to the GC log file name. The main requests were for

- the pid of the JVM (say %p)
- a date stamp (say %t)

So, for example, if we log file name is specificed as

foo.%p

it would be expanded to

foo.1234

if the pid of the JVM that created it is 1234.

See discussion on the openjdk lists for some of the proposals

http://mail.openjdk.java.net/pipermail/hotspot-gc-use/2010-May/000597.html

If we adopt 6950787: Make GC logs cyclic we could also make the sequence number of each log segment also a parameter (say: %n). In this case, the date stamp would correspond to the creation time of each log segment.