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Posted to dev@lucene.apache.org by "Aravind S (User Intent)" <s....@flipkart.com> on 2019/08/07 20:09:32 UTC
Merge multiple sorted indices
Hi,
We are currently trying to merge sorted indices in an offline process. This
process is taking a lot of time in merging. We tried using
ConcurrentMergeScheduler with tiered merge policy.
We see the merger threads to be maximum to be set as 4 in
ConcurrentMergerScheduler setDefaultMaxMergesAndThreads method.
Is there a way to decrease the time in merging this sorted indices. Is
there any recommendation that could be followed to scale merging with an
increase in a number of indices to be merged.
Regards,
Aravind S
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Re: Merge multiple sorted indices
Posted by "Aravind S (User Intent)" <s....@flipkart.com>.
Yes, we do a force merge(1). We are seeing in thread stack only 4 Lucene
merger threads are spawned in spite of disabling throttle io on merge
scheduler. We want to decrease the time it takes for merging n indices in
general.
Indices are added using MmapDirectory to the IndexWriter.
On Thu, Aug 8, 2019 at 1:09 PM Atri Sharma <at...@apache.org> wrote:
> Did you try force merging, given that your indices are static?
>
> On Thu, Aug 8, 2019 at 12:22 PM Aravind S (User Intent)
> <s....@flipkart.com> wrote:
> >
> > Hi Atri,
> >
> > Thanks for the prompt reply.
> >
> > There are no deletion or updation we are trying to merge offline
> generated sorted indices into a single sorted segment index. This entire
> process is completely offline and there is no online serving for this index
> taking no live updates like addition or deletion.
> >
> > Each index is of size is close to 1 GB. We are trying to merge 25 such
> indices into a single index using add indexes of Lucene IndexWriter using
> ConcurrentMergeScheduler.
> >
> > Is there any recommendation on how to go about merging multiple sorted
> indices into a single index more efficiently?
> >
> > Regards,
> > Aravind S
> >
> > On Thu, Aug 8, 2019, 11:57 AM Atri Sharma <at...@apache.org> wrote:
> >>
> >> Have you tried a more frequent merging? What are the average sizes of
> >> your segments, and what does your deletion/updates rate look like?
> >>
> >> On Thu, Aug 8, 2019 at 1:39 AM Aravind S (User Intent)
> >> <s....@flipkart.com> wrote:
> >> >
> >> > Hi,
> >> >
> >> > We are currently trying to merge sorted indices in an offline
> process. This process is taking a lot of time in merging. We tried using
> ConcurrentMergeScheduler with tiered merge policy.
> >> >
> >> > We see the merger threads to be maximum to be set as 4 in
> ConcurrentMergerScheduler setDefaultMaxMergesAndThreads method.
> >> >
> >> > Is there a way to decrease the time in merging this sorted indices.
> Is there any recommendation that could be followed to scale merging with an
> increase in a number of indices to be merged.
> >> >
> >> > Regards,
> >> > Aravind S
> >> >
> >> >
> -----------------------------------------------------------------------------------------
> >> >
> >> > This email and any files transmitted with it are confidential and
> intended solely for the use of the individual or entity to whom they are
> addressed. If you have received this email in error, please notify the
> system manager. This message contains confidential information and is
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> and delete this email from your system. If you are not the intended
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> strictly prohibited.
> >> >
> >> >
> >> >
> >> > Any views or opinions presented in this email are solely those of the
> author and do not necessarily represent those of the organization. Any
> information on shares, debentures or similar instruments, recommended
> product pricing, valuations and the like are for information purposes only.
> It is not meant to be an instruction or recommendation, as the case may be,
> to buy or to sell securities, products, services nor an offer to buy or
> sell securities, products or services unless specifically stated to be so
> on behalf of the Flipkart group. Employees of the Flipkart group of
> companies are expressly required not to make defamatory statements and not
> to infringe or authorise any infringement of copyright or any other legal
> right by email communications. Any such communication is contrary to
> organizational policy and outside the scope of the employment of the
> individual concerned. The organization will not accept any liability in
> respect of such communication, and the employee responsible will be
> personally liable for any damages or other liability arising.
> >> >
> >> >
> >> >
> >> > Our organization accepts no liability for the content of this email,
> or for the consequences of any actions taken on the basis of the
> information provided, unless that information is subsequently confirmed in
> writing. If you are not the intended recipient, you are notified that
> disclosing, copying, distributing or taking any action in reliance on the
> contents of this information is strictly prohibited.
> >> >
> >> >
> -----------------------------------------------------------------------------------------
> >>
> >> --
> >> Regards,
> >>
> >> Atri
> >> Apache Concerted
> >>
> >> ---------------------------------------------------------------------
> >> To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
> >> For additional commands, e-mail: dev-help@lucene.apache.org
> >>
> >
> >
> -----------------------------------------------------------------------------------------
> >
> > This email and any files transmitted with it are confidential and
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> system manager. This message contains confidential information and is
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> >
> >
> >
> > Any views or opinions presented in this email are solely those of the
> author and do not necessarily represent those of the organization. Any
> information on shares, debentures or similar instruments, recommended
> product pricing, valuations and the like are for information purposes only.
> It is not meant to be an instruction or recommendation, as the case may be,
> to buy or to sell securities, products, services nor an offer to buy or
> sell securities, products or services unless specifically stated to be so
> on behalf of the Flipkart group. Employees of the Flipkart group of
> companies are expressly required not to make defamatory statements and not
> to infringe or authorise any infringement of copyright or any other legal
> right by email communications. Any such communication is contrary to
> organizational policy and outside the scope of the employment of the
> individual concerned. The organization will not accept any liability in
> respect of such communication, and the employee responsible will be
> personally liable for any damages or other liability arising.
> >
> >
> >
> > Our organization accepts no liability for the content of this email, or
> for the consequences of any actions taken on the basis of the information
> provided, unless that information is subsequently confirmed in writing. If
> you are not the intended recipient, you are notified that disclosing,
> copying, distributing or taking any action in reliance on the contents of
> this information is strictly prohibited.
> >
> >
> -----------------------------------------------------------------------------------------
>
> --
> Regards,
>
> Atri
> Apache Concerted
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
> For additional commands, e-mail: dev-help@lucene.apache.org
>
>
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*-----------------------------------------------------------------------------------------*
*This email and any files transmitted with it are confidential and
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you should not disseminate, distribute or copy this email. Please notify
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strictly prohibited.*****
****
*Any views or opinions presented in this
email are solely those of the author and do not necessarily represent those
of the organization. Any information on shares, debentures or similar
instruments, recommended product pricing, valuations and the like are for
information purposes only. It is not meant to be an instruction or
recommendation, as the case may be, to buy or to sell securities, products,
services nor an offer to buy or sell securities, products or services
unless specifically stated to be so on behalf of the Flipkart group.
Employees of the Flipkart group of companies are expressly required not to
make defamatory statements and not to infringe or authorise any
infringement of copyright or any other legal right by email communications.
Any such communication is contrary to organizational policy and outside the
scope of the employment of the individual concerned. The organization will
not accept any liability in respect of such communication, and the employee
responsible will be personally liable for any damages or other liability
arising.*****
****
*Our organization accepts no liability for the
content of this email, or for the consequences of any actions taken on the
basis of the information *provided,* unless that information is
subsequently confirmed in writing. If you are not the intended recipient,
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_-----------------------------------------------------------------------------------------_
Re: Merge multiple sorted indices
Posted by Atri Sharma <at...@apache.org>.
Did you try force merging, given that your indices are static?
On Thu, Aug 8, 2019 at 12:22 PM Aravind S (User Intent)
<s....@flipkart.com> wrote:
>
> Hi Atri,
>
> Thanks for the prompt reply.
>
> There are no deletion or updation we are trying to merge offline generated sorted indices into a single sorted segment index. This entire process is completely offline and there is no online serving for this index taking no live updates like addition or deletion.
>
> Each index is of size is close to 1 GB. We are trying to merge 25 such indices into a single index using add indexes of Lucene IndexWriter using ConcurrentMergeScheduler.
>
> Is there any recommendation on how to go about merging multiple sorted indices into a single index more efficiently?
>
> Regards,
> Aravind S
>
> On Thu, Aug 8, 2019, 11:57 AM Atri Sharma <at...@apache.org> wrote:
>>
>> Have you tried a more frequent merging? What are the average sizes of
>> your segments, and what does your deletion/updates rate look like?
>>
>> On Thu, Aug 8, 2019 at 1:39 AM Aravind S (User Intent)
>> <s....@flipkart.com> wrote:
>> >
>> > Hi,
>> >
>> > We are currently trying to merge sorted indices in an offline process. This process is taking a lot of time in merging. We tried using ConcurrentMergeScheduler with tiered merge policy.
>> >
>> > We see the merger threads to be maximum to be set as 4 in ConcurrentMergerScheduler setDefaultMaxMergesAndThreads method.
>> >
>> > Is there a way to decrease the time in merging this sorted indices. Is there any recommendation that could be followed to scale merging with an increase in a number of indices to be merged.
>> >
>> > Regards,
>> > Aravind S
>> >
>> > -----------------------------------------------------------------------------------------
>> >
>> > This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error, please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee, you should not disseminate, distribute or copy this email. Please notify the sender immediately by email if you have received this email by mistake and delete this email from your system. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.
>> >
>> >
>> >
>> > Any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the organization. Any information on shares, debentures or similar instruments, recommended product pricing, valuations and the like are for information purposes only. It is not meant to be an instruction or recommendation, as the case may be, to buy or to sell securities, products, services nor an offer to buy or sell securities, products or services unless specifically stated to be so on behalf of the Flipkart group. Employees of the Flipkart group of companies are expressly required not to make defamatory statements and not to infringe or authorise any infringement of copyright or any other legal right by email communications. Any such communication is contrary to organizational policy and outside the scope of the employment of the individual concerned. The organization will not accept any liability in respect of such communication, and the employee responsible will be personally liable for any damages or other liability arising.
>> >
>> >
>> >
>> > Our organization accepts no liability for the content of this email, or for the consequences of any actions taken on the basis of the information provided, unless that information is subsequently confirmed in writing. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.
>> >
>> > -----------------------------------------------------------------------------------------
>>
>> --
>> Regards,
>>
>> Atri
>> Apache Concerted
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
>> For additional commands, e-mail: dev-help@lucene.apache.org
>>
>
> -----------------------------------------------------------------------------------------
>
> This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error, please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee, you should not disseminate, distribute or copy this email. Please notify the sender immediately by email if you have received this email by mistake and delete this email from your system. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.
>
>
>
> Any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the organization. Any information on shares, debentures or similar instruments, recommended product pricing, valuations and the like are for information purposes only. It is not meant to be an instruction or recommendation, as the case may be, to buy or to sell securities, products, services nor an offer to buy or sell securities, products or services unless specifically stated to be so on behalf of the Flipkart group. Employees of the Flipkart group of companies are expressly required not to make defamatory statements and not to infringe or authorise any infringement of copyright or any other legal right by email communications. Any such communication is contrary to organizational policy and outside the scope of the employment of the individual concerned. The organization will not accept any liability in respect of such communication, and the employee responsible will be personally liable for any damages or other liability arising.
>
>
>
> Our organization accepts no liability for the content of this email, or for the consequences of any actions taken on the basis of the information provided, unless that information is subsequently confirmed in writing. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.
>
> -----------------------------------------------------------------------------------------
--
Regards,
Atri
Apache Concerted
---------------------------------------------------------------------
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For additional commands, e-mail: dev-help@lucene.apache.org
Re: Merge multiple sorted indices
Posted by "Aravind S (User Intent)" <s....@flipkart.com>.
Hi Atri,
Thanks for the prompt reply.
There are no deletion or updation we are trying to merge offline generated
sorted indices into a single sorted segment index. This entire process is
completely offline and there is no online serving for this index taking no
live updates like addition or deletion.
Each index is of size is close to 1 GB. We are trying to merge 25 such
indices into a single index using add indexes of Lucene IndexWriter using
ConcurrentMergeScheduler.
Is there any recommendation on how to go about merging multiple sorted
indices into a single index more efficiently?
Regards,
Aravind S
On Thu, Aug 8, 2019, 11:57 AM Atri Sharma <at...@apache.org> wrote:
> Have you tried a more frequent merging? What are the average sizes of
> your segments, and what does your deletion/updates rate look like?
>
> On Thu, Aug 8, 2019 at 1:39 AM Aravind S (User Intent)
> <s....@flipkart.com> wrote:
> >
> > Hi,
> >
> > We are currently trying to merge sorted indices in an offline process.
> This process is taking a lot of time in merging. We tried using
> ConcurrentMergeScheduler with tiered merge policy.
> >
> > We see the merger threads to be maximum to be set as 4 in
> ConcurrentMergerScheduler setDefaultMaxMergesAndThreads method.
> >
> > Is there a way to decrease the time in merging this sorted indices. Is
> there any recommendation that could be followed to scale merging with an
> increase in a number of indices to be merged.
> >
> > Regards,
> > Aravind S
> >
> >
> -----------------------------------------------------------------------------------------
> >
> > This email and any files transmitted with it are confidential and
> intended solely for the use of the individual or entity to whom they are
> addressed. If you have received this email in error, please notify the
> system manager. This message contains confidential information and is
> intended only for the individual named. If you are not the named addressee,
> you should not disseminate, distribute or copy this email. Please notify
> the sender immediately by email if you have received this email by mistake
> and delete this email from your system. If you are not the intended
> recipient, you are notified that disclosing, copying, distributing or
> taking any action in reliance on the contents of this information is
> strictly prohibited.
> >
> >
> >
> > Any views or opinions presented in this email are solely those of the
> author and do not necessarily represent those of the organization. Any
> information on shares, debentures or similar instruments, recommended
> product pricing, valuations and the like are for information purposes only.
> It is not meant to be an instruction or recommendation, as the case may be,
> to buy or to sell securities, products, services nor an offer to buy or
> sell securities, products or services unless specifically stated to be so
> on behalf of the Flipkart group. Employees of the Flipkart group of
> companies are expressly required not to make defamatory statements and not
> to infringe or authorise any infringement of copyright or any other legal
> right by email communications. Any such communication is contrary to
> organizational policy and outside the scope of the employment of the
> individual concerned. The organization will not accept any liability in
> respect of such communication, and the employee responsible will be
> personally liable for any damages or other liability arising.
> >
> >
> >
> > Our organization accepts no liability for the content of this email, or
> for the consequences of any actions taken on the basis of the information
> provided, unless that information is subsequently confirmed in writing. If
> you are not the intended recipient, you are notified that disclosing,
> copying, distributing or taking any action in reliance on the contents of
> this information is strictly prohibited.
> >
> >
> -----------------------------------------------------------------------------------------
>
> --
> Regards,
>
> Atri
> Apache Concerted
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
> For additional commands, e-mail: dev-help@lucene.apache.org
>
>
--
*-----------------------------------------------------------------------------------------*
*This email and any files transmitted with it are confidential and
intended solely for the use of the individual or entity to whom they are
addressed. If you have received this email in error, please notify the
system manager. This message contains confidential information and is
intended only for the individual named. If you are not the named addressee,
you should not disseminate, distribute or copy this email. Please notify
the sender immediately by email if you have received this email by mistake
and delete this email from your system. If you are not the intended
recipient, you are notified that disclosing, copying, distributing or
taking any action in reliance on the contents of this information is
strictly prohibited.*****
****
*Any views or opinions presented in this
email are solely those of the author and do not necessarily represent those
of the organization. Any information on shares, debentures or similar
instruments, recommended product pricing, valuations and the like are for
information purposes only. It is not meant to be an instruction or
recommendation, as the case may be, to buy or to sell securities, products,
services nor an offer to buy or sell securities, products or services
unless specifically stated to be so on behalf of the Flipkart group.
Employees of the Flipkart group of companies are expressly required not to
make defamatory statements and not to infringe or authorise any
infringement of copyright or any other legal right by email communications.
Any such communication is contrary to organizational policy and outside the
scope of the employment of the individual concerned. The organization will
not accept any liability in respect of such communication, and the employee
responsible will be personally liable for any damages or other liability
arising.*****
****
*Our organization accepts no liability for the
content of this email, or for the consequences of any actions taken on the
basis of the information *provided,* unless that information is
subsequently confirmed in writing. If you are not the intended recipient,
you are notified that disclosing, copying, distributing or taking any
action in reliance on the contents of this information is strictly
prohibited.*
_-----------------------------------------------------------------------------------------_
Re: Merge multiple sorted indices
Posted by Atri Sharma <at...@apache.org>.
Have you tried a more frequent merging? What are the average sizes of
your segments, and what does your deletion/updates rate look like?
On Thu, Aug 8, 2019 at 1:39 AM Aravind S (User Intent)
<s....@flipkart.com> wrote:
>
> Hi,
>
> We are currently trying to merge sorted indices in an offline process. This process is taking a lot of time in merging. We tried using ConcurrentMergeScheduler with tiered merge policy.
>
> We see the merger threads to be maximum to be set as 4 in ConcurrentMergerScheduler setDefaultMaxMergesAndThreads method.
>
> Is there a way to decrease the time in merging this sorted indices. Is there any recommendation that could be followed to scale merging with an increase in a number of indices to be merged.
>
> Regards,
> Aravind S
>
> -----------------------------------------------------------------------------------------
>
> This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error, please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee, you should not disseminate, distribute or copy this email. Please notify the sender immediately by email if you have received this email by mistake and delete this email from your system. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.
>
>
>
> Any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the organization. Any information on shares, debentures or similar instruments, recommended product pricing, valuations and the like are for information purposes only. It is not meant to be an instruction or recommendation, as the case may be, to buy or to sell securities, products, services nor an offer to buy or sell securities, products or services unless specifically stated to be so on behalf of the Flipkart group. Employees of the Flipkart group of companies are expressly required not to make defamatory statements and not to infringe or authorise any infringement of copyright or any other legal right by email communications. Any such communication is contrary to organizational policy and outside the scope of the employment of the individual concerned. The organization will not accept any liability in respect of such communication, and the employee responsible will be personally liable for any damages or other liability arising.
>
>
>
> Our organization accepts no liability for the content of this email, or for the consequences of any actions taken on the basis of the information provided, unless that information is subsequently confirmed in writing. If you are not the intended recipient, you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.
>
> -----------------------------------------------------------------------------------------
--
Regards,
Atri
Apache Concerted
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