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From Shawn Heisey <elyog...@elyograg.org>
Subject Re: Ensemble fails when one node looses connectivity
Date Fri, 02 Mar 2018 15:47:26 GMT
On 3/2/2018 6:54 AM, Jim Keeney wrote:
> Thanks for jumping in on the ZK side as well.
>
> I will take a hard look at my config files but I checked and I do not have
> any one file over 1MB. The combined files (10 indexes) is 2.2MB.
>
> I am using micros for the nodes which are very limited in memory.
>
> I'm not currently using a java.env file so I guess I'm using the default
> values for the JVM which is typically xmx512M if I remember correctly.
>
> Could it be just a memory issue?

Usually Java on Linux has a default heap size of about 4GB.  But it 
would be highly dependent on the amount of memory actually present on 
the machine.  Just yesterday, I saw Java report a 6GB default heap size, 
on a machine with 24GB of memory. Information I can find about AWS 
instance types says that a micro instance has 1GB of memory.  So the 
default heap size is probably quite small.

Even in small server situations, I would strongly recommend that anytime 
you have a java commandline, you define -Xmx for the max heap, and -Xms 
should probably be set as well, to the same value as -Xmx.  That way 
you're not relying on defaults, you're absolutely sure what the heap 
size is.

For ZK servers handling 2 megabytes of config data plus the rest of a 
small SolrCloud install, something like 256MB or 512MB of heap would 
probably be plenty.  ZK holds a copy of its entire database in memory.  
Small SolrCloud installs won't put much of a load on ZK.  A micro 
instance should be plenty for ZK when the software using it is Solr, as 
long as that's the only thing it's running.

Thanks,
Shawn


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