In an ideal minor collection the live objects are copied from one part of the *young* generation (the eden space plus the first survivor space) to another part of the *young* generation (the second survivor space).
See: http://java.sun.com/docs/hotspot/gc1.4.2/ On Mon, Jan 3, 2011 at 12:50 PM, Wayne <[email protected]> wrote: > We have an 8GB heap. What should newsize be? I just had another node die > hard after going into a CMF storm. I swear it had solid CMFs 30+ in a row. > > I have no idea what eden space is or how to see what it is. ?? > > Not knowing what else to do I will start using some of the Cassandra > settings I used to improve it by setting the occupancy fraction. Any other > ideas??? > > Thanks. > > On Mon, Jan 3, 2011 at 12:40 PM, Stack <[email protected]> wrote: > > > zookeeper.session.timeout is the config. to toggle. Its set to > > 180seconds in 0.90.0RC. Is it not so in your deploy? > > > > On Mon, Jan 3, 2011 at 5:13 AM, Wayne <[email protected]> wrote: > > > > > > Any help or suggestions would be appreciated. Parnew was getting large > > and > > > taking too long (> 100ms) so I will try to limit the size with the > > > suggestion from the performance tuning page (-XX:NewSize=6m > > > -XX:MaxNewSize=6m). > > > > > > > The CMS concurrent mode failure will be about trying to promote from > > new space up into the tenured heap but there's not the space in > > tenured heap to take the promotion because of fragmentation. You > > could try putting an upper bound on the new size (What size had your > > eden space grown too?). That would put off the CMF some but in long > > running app., CMF seems unavoidable, yeah. > > > > A newsize of 6M is way too small given the heap sizes you've been > > bandy'ing about (You were thinking 64M? Even then, that seems too > > small). > > > > On failure of the node, all the regions came up again on new servers OK? > > > > St.Ack > > >
