On 5/30/2019 9:58 AM, Markus Jelsma wrote:
Hello,
It solves the problem! So, with this flag disabled, would that mean our Solr
would have lower performance than with it?
That flag ended up in the config because I was using it in my GC
experiments, and my wiki page appears to have been used as the basis for
the G1 config in 8.1:
https://wiki.apache.org/solr/ShawnHeisey#Current_experiments
I do have a note about that flag on that page, I found the blog post it
links to very fascinating.
A machine that's writing a lot of data to the disks where Java stores
performance data (and I think heavy indexing with Solr would qualify)
MIGHT see real performance gains with that option ... but enabling it
*disables* many of Java's commandline and GUI tools, as you found out.
An alternate option is to have a filesystem on separate disks for Java's
temp directory, normally /tmp on *NIX systems. If the disk/filesystem
where Java's performance data lives is not seeing a lot of writes, then
the problem that this flag eliminates won't happen.
Thanks,
Shawn
