On 1/29/2018 2:02 PM, Scott Prentice wrote:
Thanks, Shawn. I was wondering if there was something going on with IP redirection that was causing confusion. Any thoughts on how to debug? And, what do you mean by "extreme garbage collection pauses"? Is that Solr garbage collection or the OS itself? There's really nothing happening on this machine, it's purely for testing so there shouldn't be any extra load from other processes.
Garbage collection is one of the primary features of Java's memory management. It's not Solr or the OS.
If the java heap is really enormous, you can end up with long pauses, but I wouldn't expect them to be frequent unless the index is also really huge.
A very common issue that can cause even worse pause issues than a large heap is a heap that's too small, but not quite small enough to cause Java to completely run out of heap memory. The default max heap size in recent Solr versions is 512MB, which is very small. A Java program (which Solr is) can never use more heap memory than the maximum it is configured with, even if the machine has more memory available.
This paragraph is included because you mentioned IP redirection: Extreme care must be used when setting up SolrCloud on virtual machines where accessing the VM has to go through any kind of IP translation. SolrCloud keeps track of how to reach each server in the cloud and if it stores an untranslated address when you need the translated address (or vice-versa), things are not going to work. Generally speaking translated addresses are going to be problematic for SolrCloud, and should not be used.
Thanks, Shawn
