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Posted to solr-user@lucene.apache.org by Nguyen Manh Tien <ti...@gmail.com> on 2017/05/23 14:46:23 UTC
High CPU when use grouping group.ngroups=true
Hi All,
I recently switch from solr field collapse/expand to grouping for collapse
search result
All seem good but CPU is always high (80-100%) when i set param
group.ngroups=true.
We set ngroups=true to get number of groups so that we can paginate search
result correctly.
Due to CPU issue we need to turn it off.
Is ngroups=true is expensive feature? Is there any way to prevent CPU issue
and still have correct pagination.
Thanks,
Tien
Re: High CPU when use grouping group.ngroups=true
Posted by Nguyen Manh Tien <ti...@gmail.com>.
Without using ngroups=true, is there any way to handle pagination correctly
when we collapse result using grouping?
Regards,
Tien
On Tue, May 23, 2017 at 9:55 PM, Nguyen Manh Tien <tien.nguyenmanh@gmail.com
> wrote:
> The collapse field is high-cardinality field. I haven't profiling yet but
> will do it.
>
> Thanks,
> Tien
>
> On Tue, May 23, 2017 at 9:48 PM, Erick Erickson <er...@gmail.com>
> wrote:
>
>> How many unique values in your group field? For high-cardinality
>> fields there's quite a bit of bookkeeping that needs to be done.
>>
>> Have you tried profiling to see where the CPU time is being spent?
>>
>> Best,
>> Erick
>>
>> On Tue, May 23, 2017 at 7:46 AM, Nguyen Manh Tien
>> <ti...@gmail.com> wrote:
>> > Hi All,
>> >
>> > I recently switch from solr field collapse/expand to grouping for
>> collapse
>> > search result
>> > All seem good but CPU is always high (80-100%) when i set param
>> > group.ngroups=true.
>> >
>> > We set ngroups=true to get number of groups so that we can paginate
>> search
>> > result correctly.
>> > Due to CPU issue we need to turn it off.
>> >
>> > Is ngroups=true is expensive feature? Is there any way to prevent CPU
>> issue
>> > and still have correct pagination.
>> >
>> > Thanks,
>> > Tien
>>
>
>
Re: High CPU when use grouping group.ngroups=true
Posted by Nguyen Manh Tien <ti...@gmail.com>.
The collapse field is high-cardinality field. I haven't profiling yet but
will do it.
Thanks,
Tien
On Tue, May 23, 2017 at 9:48 PM, Erick Erickson <er...@gmail.com>
wrote:
> How many unique values in your group field? For high-cardinality
> fields there's quite a bit of bookkeeping that needs to be done.
>
> Have you tried profiling to see where the CPU time is being spent?
>
> Best,
> Erick
>
> On Tue, May 23, 2017 at 7:46 AM, Nguyen Manh Tien
> <ti...@gmail.com> wrote:
> > Hi All,
> >
> > I recently switch from solr field collapse/expand to grouping for
> collapse
> > search result
> > All seem good but CPU is always high (80-100%) when i set param
> > group.ngroups=true.
> >
> > We set ngroups=true to get number of groups so that we can paginate
> search
> > result correctly.
> > Due to CPU issue we need to turn it off.
> >
> > Is ngroups=true is expensive feature? Is there any way to prevent CPU
> issue
> > and still have correct pagination.
> >
> > Thanks,
> > Tien
>
Re: High CPU when use grouping group.ngroups=true
Posted by Erick Erickson <er...@gmail.com>.
How many unique values in your group field? For high-cardinality
fields there's quite a bit of bookkeeping that needs to be done.
Have you tried profiling to see where the CPU time is being spent?
Best,
Erick
On Tue, May 23, 2017 at 7:46 AM, Nguyen Manh Tien
<ti...@gmail.com> wrote:
> Hi All,
>
> I recently switch from solr field collapse/expand to grouping for collapse
> search result
> All seem good but CPU is always high (80-100%) when i set param
> group.ngroups=true.
>
> We set ngroups=true to get number of groups so that we can paginate search
> result correctly.
> Due to CPU issue we need to turn it off.
>
> Is ngroups=true is expensive feature? Is there any way to prevent CPU issue
> and still have correct pagination.
>
> Thanks,
> Tien