I’d look for an OutOfMemory problem before going too much farther.
The simplest way to see if that’s in the right direction would be to
run your SolrJ program with a massive memory size. Perhaps monitor
your program with jconsole or similar to see if there’s any clues about
memory usage.
OOMs lead to unpredictable behavior, so it’s at least a possibility that
this is the root cause. If so, there’s nothing SolrJ can do about it exactly
because the state of a program is indeterminate afterwards, even if the
OOM is caught somewhere. I suppose you could also try to catch that
exception in the top-level of your program.
I’m assuming a stand-alone program here, if you’re running some custom
code in Solr itself, make sure the oom-killer script is running.
Best,
Erick
> On Jun 6, 2020, at 8:23 AM, Jim Anderson <jjanderson52...@gmail.com> wrote:
>
> Shawn,
>
> Thanks for the explanation. Very good response.
>
> The first paragraph helped clarify what a collection is. I have read quite
> about about Solr. There is so much to absorb that it is slowly sinking in.
> Your 2nd paragraph definitely answered my question, i.e. passing a core
> name should be ok when a collection name is specified as a method argument.
> This is what I did.
>
> Regarding the 3rd paragraph, it is good to know that Solrj is fairly robust
> and should not be crashing. Nevertheless, that is what is happening. The
> call to client.query() is wrapped in a try/catch sequence. Apparently no
> exceptions were detected, or the program crashed before the exception could
> be raised.
>
> My next step is to check where I can report this to the Solr folks and see
> if they can figure out what it is crashing. BTW, I had not checked my
> output file before this morning. The output file indicates that the program
> ran to completion, so I am guessing that at least one other thread is being
> created and that that thread is crashing.
>
> Regards,
> Jim
>
> On Fri, Jun 5, 2020 at 10:52 PM Shawn Heisey <apa...@elyograg.org> wrote:
>
>> On 6/5/2020 4:24 PM, Jim Anderson wrote:
>>> I am running my first solrj program and it is crashing when I call the
>>> method
>>>
>>> client.query("coreName",queryParms)
>>>
>>> The API doc says the string should be a collection. I'm still not sure
>>> about the difference between a collection and a core, so what I am doing
>> is
>>> likely illegal. Given that I have created a core, create a collection
>> from
>>> it so that I can truly pass a collection name to the query function?
>>
>> The concept of a collection comes from SolrCloud. A collection is made
>> up of one or more shards. A shard is made up of one or more replicas.
>> Each replica is a core. If you're not running SolrCloud, then you do
>> not have collections.
>>
>> Wherever SolrJ docs says "collection" as a parameter for a request, it
>> is likely that you can think "core" instead and have it still be
>> correct. If you're running SolrCloud, you'll want to be very careful to
>> know the difference.
>>
>> It seems very odd for a SolrJ query to cause the program to crash. It
>> would be pretty common for it to throw an exception, but that's not the
>> same as a crash, unless exception handling is incorrect or missing.
>>
>> Thanks,
>> Shawn
>>
