It would be a bit extensive, but would be interesting to know if a similar error/situation occurs in Linux too (there are kernel level debugging tools available for this open source OS)
On Wed, 6 Jun 2018, 10:59 Shawn Heisey, <apa...@elyograg.org> wrote: > On 6/5/2018 10:26 PM, TK Solr wrote: > > I visualized the GC log with GCMV (GCVM?) and the graph shows Solr was > > using less than half of the heap space at the peak. > > This Solr doesn't get much query traffic and no indexing was running. > > It's really a sudden death of JVM with no trace. > > > > If you aren't concerned about what you see in a GC analysis, then the > heap may not be an issue. FYI, this is where I would have sent the log > once I got it: > > http://gceasy.io/ > > This website does a VERY good job of detecting possible problems with > the heap and GC. > > > The only concern I have is that the Solr config files are that of Solr > > 5.x and they just upgraded to Solr 6.6. But I understand Solr 6 > > supports Solr 5 compatible mode. Has there been any issue in the > > compatibility mode? > > If the config was actually *designed* for 5.x, then it should have > little problem working in 6.x. If it was designed for an earlier > version and just happened to work in 5.x, then I would be less > optimistic about it working in 6.x. That said ... it is very unlikely > that anything in the index config files would cause crashes, even if > there is a compatibility problem. > > The simple truth is that most Java software, including Solr, just > doesn't ever crash unless there's something VERY wrong. > > Actual crashes do happen in the wild, they're just very rare. Extremely > severe memory starvation at the OS level can cause problems where > processes die without any logging, or the OS kills them explicitly. If > the java heap is properly sized for the system, that shouldn't be > possible. Since you're running Solr 6, you're running Java 8 minimum. > PermGen is gone in Java 8. Similar issues to what used to happen with > PermGen can still happen with the new piece called Metaspace, but if the > overall system config is good, that shouldn't be a problem. > > Thanks, > Shawn > >
