On 10/10/2018 10:08 PM, Sourav Moitra wrote:
We have a Solr server with 8gb of memory. We are using solr in cloud
mode, solr version is 7.5, Java version is Oracle Java 9 and settings
for Xmx and Xms value is 2g but we are observing that the RAM getting
used to 98% when doing indexing.
How can I ensure that SolrCloud doesn't use more than N GB of memory ?
Where precisely are you seeing the 98% usage? It is completely normal
for a modern operating system to report that almost all the system
memory is in use, at least after the system has been shuffling a lot of
data. All modern operating systems will use memory that has not been
specifically allocated to programs for disk caching purposes, and system
information tools will generally indicate that this memory is in use,
even though it can be instantly claimed by any program that requests it.
https://en.wikipedia.org/wiki/Page_cache
If you tell a Java program that it is limited to a 2GB heap, then that
program will never use more than 2GB, plus a little extra for the java
runtime itself. I cannot give you an exact figure for that little bit
extra. But every bit of data on disk that Solr accesses will end up (at
least temporarily) in the operating system's disk cache -- using that
unallocated memory.
https://wiki.apache.org/solr/SolrPerformanceProblems#RAM
Thanks,
Shawn
