Solr 5 admin screen description

[davidphilip cherian <da...@gmail.com>]

Hi Group,

 I would like to understand the solr's dashboard screen, particularly the
screen *system* properties displayed such as Physical Memory, Swap Space,
File Desc. count and etc. 1. What is the importance of file descriptor
count?  2. Dashboard shows that it has taken 16 gb of space out of which
14.3g is used. I did not understand on what basis it allocated 16 gb? How
do I increase it?If my index sizes increase, will it automatically extend
if there is hard disc space available?  I couldn't find these info. on
reference guide. Could you please point me to any doc/blog that explains
this?

Re: Solr 5 admin screen description

[Shawn Heisey <ap...@elyograg.org>]

On 3/13/2015 9:48 AM, davidphilip cherian wrote:
>  I would like to understand the solr's dashboard screen, particularly the
> screen *system* properties displayed such as Physical Memory, Swap Space,
> File Desc. count and etc. 1. What is the importance of file descriptor
> count?  2. Dashboard shows that it has taken 16 gb of space out of which
> 14.3g is used. I did not understand on what basis it allocated 16 gb? How
> do I increase it?If my index sizes increase, will it automatically extend
> if there is hard disc space available?  I couldn't find these info. on
> reference guide. Could you please point me to any doc/blog that explains
> this?

The system information is taken directly from the operating system, and
has no special meaning within Solr.  That info means the same things as
it would for any other program.  No descriptions are given because the
names on the graphs *are* the description.  We could do better in this
department, but these are general concepts that are not unique to Solr
... so understanding them fully really does require that you already
have training in general computer concepts or experience as a sysadmin.

If the 16GB you have mentioned is on the physical memory graph, then
that is the total memory in the machine, and the OS says that 14.3GB of
that is in use.  Solr will be part of that, but those numbers are not
specific to Solr.  A note on physical memory usage:  It is completely
normal for a computer to show that nearly 100 percent of physical memory
is in use.  It's simply how computers work.  Search google for "page
cache" for more info.  The first hit should be a wikipedia article,
which is an excellent resource.

The JVM-Memory graph *does* pertain directly to Solr -- it shows
information about the java heap for the process that is running Solr. 
Discussions about the java heap could go on for days ... like
system-level information, it's a topic that requires expertise beyond
Solr itself.

Information about the index size and free disk space are not available
on the dashboard.  Index size information is available elsewhere in the
UI, but I don't think that information about free disk space is readily
available from Solr.  Your characterization is correct -- if there is
disk space available and you index more documents, then the indexing
will succeed and the index will get bigger.

Thanks,
Shawn