You say you tripled the memory. Up to what? Tripling from 500M t0 1.5G isn't likely enough, tripling from 6G to 18G is something else again....
You can take a look through any of the memory profilers and try to catch the objects (and where they're being allocated). The second is to look at the stack trace (presuming you don't have an OOM killer script running) and perhaps triangulate that way. Best, Erick On Thu, Oct 20, 2016 at 11:44 AM, Jihwan Kim <jihwa...@gmail.com> wrote: > Thank you Shawn. I understand the two options. > After my own testing with a smaller heap, I increased my heap size more than > triple, but OOME happens again with my testing cases under the controlled > thread process. Increased heap size just delayed the OOME. > > Can you provide a feedback on my second question: When the core reload > happens successfully (no matter it throws the exception or not), does Solr > need to call the openNewSearcherAndUpdateCommitPoint method? > > As I described on my previous email, a thread created from > openNewSearcherAndUpdateCommitPoint method hangs and cause a high CPU usage > and a slow response time. Attached image is the thread hung. > > > > On Thu, Oct 20, 2016 at 9:29 AM, Shawn Heisey <apa...@elyograg.org> wrote: >> >> On 10/20/2016 8:44 AM, Jihwan Kim wrote: >> > We are using Solr 4.10.4 and experiencing out of memory exception. It >> > seems the problem is cause by the following code & scenario. >> >> When you get an OutOfMemoryError exception that tells you there's not >> enough heap space, the place where the exception happens is frequently >> unrelated to the actual source of the problem. Also, unless the >> programmer engages in extraordinary effort, encountering OOME will cause >> program behavior to become completely unpredictable. Most of Solr has >> *NOT* had the benefit of extraordinary effort to handle OOME gracefully. >> >> Before continuing with troubleshooting of SnapPuller, you're going to >> need to fix the OOME error. When you run out of memory, that is likely >> to be the CAUSE of any errors you're seeing, not a symptom. >> >> There are exactly two ways to deal with OOME: Increase the max heap, or >> take steps to reduce the amount of heap required. Increasing the heap >> is the easiest option, and typically the first step. Sometimes it's the >> ONLY option. >> >> https://wiki.apache.org/solr/SolrPerformanceProblems#Java_Heap >> >> Thanks, >> Shawn >> >