DSpace 6.3 - hibernate - really slow performance.

[Karol Sokalski]

Hi,

two weeks ago i upgraded DSpace from 5.4 to 6.3. Everything looks pretty good, but today, webadmin told me "creating new collections takes a long time, or is imposible (Internel server error) when i push "next""

 

I enabled debug mode, and i saw that, everytime when i push "Next" in dspace.log starting a lot of operations like this connected with hibernate:

2021-01-25 17:50:26,746 DEBUG org.hibernate.engine.internal.Collections @ Collection found: [org.dspace.eperson.Group.groups#4491bccf-303c-434343395-823497b-d8243234092d655fb3], was: [org.dspace.eperson.Group.groups#4491bccf-303c-43434395-897b-d802343292d655fb3] (uninitialized)

2021-01-25 17:50:26,746 DEBUG org.hibernate.engine.internal.Collections @ Collection found: [org.dspace.eperson.Group.parentGroups#4491bccf-303c-439234325-89234427b-d8092d655fb3], was: [org.dspace.eperson.Group.parentGroups#4491bccf-303c-43924325-8923427b-d8092d655fb3] (uninitialized)

2021-01-25 17:50:26,746 DEBUG org.hibernate.engine.internal.Collections @ Collection found: [org.dspace.eperson.Group.supervisedItems#4491bccf-303c-439234325-897b-d8092d655fb3], was: [org.dspace.eperson.Group.supervisedItems#4491bccf-303c-43243295-897b-d8092d655fb3] (uninitialized)

2021-01-25 17:50:26,746 DEBUG org.hibernate.engine.internal.Collections @ Collection found: [org.dspace.content.DSpaceObject.handles#0d2abd2f-e192-4a8234322-9e49-11e2e0f05c18], was: [org.dspace.content.DSpaceObject.handles#0d2abd2f-e192-4a8234322-9e49-11e2e0f05c18] (uninitialized)

2021-01-25 17:50:26,746 DEBUG org.hibernate.engine.internal.Collections @ Collection found: [org.dspace.content.DSpaceObject.metadata#0d2abd2f-e192-4a243282-9e49-11e2e0f05c18], was: [org.dspace.content.DSpaceObject.metadata#0d2abd2f-e192-4a2342382-9e49-11e2e0f05c18] (uninitialized)

The problem exist with:

- Create collection when i check 

   * The submission workflow will include an accept/reject step

   * The submission workflow will include an accept/reject/edit metadata step

   * The submission workflow will include an edit metadata step

    *This collection will have delegated collection administrators

The same, when i edditing  new collection first time (accept/reject/edit etc).

It looks like problem with new mechanism "hibernate". Is posible to increase performance ? For example by modify (hibernate.cfg.xml) or something else?

Thanks,

Karol

Thanks,

[Alan Orth]

Dear Karol,

Yes I noticed the same thing when moving from DSpace 5 to 6 in 2020: indexing performance, REST API responses, item submission, etc are all much slower in DSpace 6. More specifically, indexing is three times slower in our repository of ~90,000 items, harvesting the entire repository via REST API takes ~10 hours, and editors have complained about submission times. Etc etc.

In a February, 2020 thread on this list¹ I did an extensive performance analysis between DSpace 5.10 and 6.4 Discovery indexing to try to understand the difference. I'm attaching the flame graphs from that research here (download them and open in Firefox, they are interactive SVGs). The sample time was sixty seconds. The length of a bar is the time the function spent on the CPU. The height grows with the spawning of children. This clearly shows that Hibernate has a significant overhead in DSpace. I am not a Java developer (let alone an expert in Hibernate). I also hope that someone can figure this out.

Cheers,

¹ See my thread with subject "Slow Discovery indexing performance in DSpace 6"

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[Karol Sokalski]

Alan,

thank You, for sad, but helpfully answer. Maybe DSpace7 will be without this problem...

Cheers!

Karol

[Alan Orth]

Does anyone have any experience to share regarding DSpace 7? We are really suffering with DSpace 6:

- Discovery indexing of 90,000 items in DSpace 6.3 takes four or five hours, where it used to take one or two in Dspace 5.8 on the same hardware

- Harvesting all our items via the REST API /items endpoint in DSpace 6.3 takes ten hours, where it used to take half of that in DSpace 5.8 (though the DSpace REST API has never been performant)

- Ingesting a CSV file with 1,000 metadata-only items takes one hour in DSpace 6.3

At this rate I'm wondering who I can pay to troubleshoot the Hibernate issues in DSpace 6. Does DSpace 7 still have these issues? It's starting to be a real drag for us. I don't know how owners of mid-to-large DSpace repositories survive on the modern web with performance profiles like this. I will investigate nginx caching of API responses to try to lessen the load.

Regards,

To view this discussion on the web visit https://groups.google.com/d/msgid/dspace-tech/c9ad3191-c1b8-457c-8c1b-ac0b34aac3fdn%40googlegroups.com.

[Karol Sokalski]

UP. Problem still exist... :(

[Alan Orth]

Dear Karol,

Do you mean that the issue still exists on DSpace 7? I have not used it yet.

Cheers,

All messages to this mailing list should adhere to the Code of Conduct: https://duraspace.org/about/policies/code-of-conduct/

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