#2346 closed defect (wontfix)

cloud backend uses lots of expensive LIST requests

Reported by: cloud_trouble Owned by:
Priority: normal Milestone: 1.15.0
Component: code-storage Version: cloud-branch
Keywords: cloud-backend S3 cost optimization Cc:
Launchpad Bug:

Description (last modified by daira)

The cloud backend uses lots of expensive LIST requests with an Amazon S3 bucket from heavy use of GET Bucket. The GET Bucket request is billed as a LIST request and is 10 times more expensive than a GET Object request.

These LIST requests can be a large portion of the cost of using an S3 backend storage node. For example, my logs show 1.5 times as many GET Bucket requests as GET Object requests (with two storage nodes, one S3 bucket and one desktop computer) and the cost exceeds storage, transfer, and EC2 costs.

Here is some relevant code: https://github.com/LeastAuthority/tahoe-lafs/blob/cloud-rebased/src/allmydata/storage/backends/cloud/cloud_common.py#L426

And relevant chat on IRC:

<daira1> the list of shares is stored in a local database called the leasedb. that was added recently on the cloud branch, so I suspect we're not making optimal use of it yet <daira1> ISTR that zooko was arguing for treating the leasedb as authoritative as to whether a share exists, and I was arguing against for a reason that I can't remember right now. there's a ticket about it <zooko> Yes, the arguments about the trade-offs of treating leasedb as authoritative vs. advisory are encoded into tickets. <zooko> I seem to recall that treating leasedb as authoritative gets nice performance, including for this particular aspect, while trading off some other values.

Change History (5)

comment:1 Changed at 2014-12-03T23:00:38Z by daira

  • Description modified (diff)
  • Keywords cloud-backend added; cloud removed
  • Milestone changed from undecided to 1.12.0
  • Summary changed from cloud backend uses losts of expensive LIST requests to cloud backend uses lots of expensive LIST requests

comment:2 Changed at 2016-03-22T05:02:25Z by warner

  • Milestone changed from 1.12.0 to 1.13.0

Milestone renamed

comment:3 Changed at 2016-06-28T18:17:14Z by warner

  • Milestone changed from 1.13.0 to 1.14.0

renaming milestone

comment:4 Changed at 2020-06-30T14:45:13Z by exarkun

  • Milestone changed from 1.14.0 to 1.15.0

Moving open issues out of closed milestones.

comment:5 Changed at 2020-10-30T12:35:44Z by exarkun

  • Resolution set to wontfix
  • Status changed from new to closed

The established line of development on the "cloud backend" branch has been abandoned. This ticket is being closed as part of a batch-ticket cleanup for "cloud backend"-related tickets.

If this is a bug, it is probably genuinely no longer relevant. The "cloud backend" branch is too large and unwieldy to ever be merged into the main line of development (particularly now that the Python 3 porting effort is significantly underway).

If this is a feature, it may be relevant to some future efforts - if they are sufficiently similar to the "cloud backend" effort - but I am still closing it because there are no immediate plans for a new development effort in such a direction.

Tickets related to the "leasedb" are included in this set because the "leasedb" code is in the "cloud backend" branch and fairly well intertwined with the "cloud backend". If there is interest in lease implementation change at some future time then that effort will essentially have to be restarted as well.

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