Mongoose: Index creation fails after creating the first background index

Created on 28 Feb 2013 · 11Comments · Source: Automattic/mongoose

Index creation fails with error MongoError: cannot add index with a background operation in progress for all but the first index if there are many indexes defined for a schema and the indexes take some time to create.

Run https://github.com/hvrauhal/mongoosebug to reproduce.

This is related to issue #1059

confirmed-bug

Source

hvrauhal

Most helpful comment

ah ok, reproduced it. thanks

aheckmann on 28 Feb 2013

😄2

All 11 comments

"With mongo 2.2.3 and mongoose 3.5.4"

aheckmann on 28 Feb 2013

One of the best bug reports ever! Thanks. Yet I still cannot reproduce. Any other tips for me?

aheckmann on 28 Feb 2013

ah ok, reproduced it. thanks

aheckmann on 28 Feb 2013

😄2

Needed more kittens for the index creation to take a long enough time?

hvrauhal on 28 Feb 2013

Somewhat, I needed to add all of the docs before triggering index creation.

On Thu, Feb 28, 2013 at 10:43 AM, Heikki Rauhala
[email protected]:

Needed more kittens for the index creation to take a long enough time?

—
Reply to this email directly or view it on GitHubhttps://github.com/LearnBoost/mongoose/issues/1365#issuecomment-14249647
.

Aaron
@aaronheckmann https://twitter.com/#!/aaronheckmann

aheckmann on 1 Mar 2013

Great bug report.

We have been bitten by this a few times but weren't sure where the fault lies. Disappearing indexes is not a very fun situation.

Any chance I could be of help or a possible ETA on this?

addisonj on 2 Mar 2013

@addisonj indexes never "disappeared". Listen to the index event of your model to be informed when the indexing attempts complete. The error, if any, is passed along.

aheckmann on 2 Mar 2013

@addisonj if you'd like to submit the fix the function is in lib/model.js called ensureIndexes. Add a test that reproduces to test/model.indexing.test.js

If you don't get to it over the weekend I'll get it sometime next week.

aheckmann on 2 Mar 2013

@aheckmann apologies for not making that clear. We have some import jobs that drop a rebuild indexes and have seen this behavior. I am glad to have that mystery answered (we thought it was a mongodb issue).

Thanks for the hint on the event though. I can use that as a workaround for now.

Awesome project BTW and apologies again if that first message came off a bit harsh!

addisonj on 2 Mar 2013

@addisonj no worries, you didn't come off harsh. sorry if I gave that impression. Maybe I shouldn't write comments while walking in traffic :)

aheckmann on 2 Mar 2013

Currently MongoDB does not permit multiple background indexes running. I've confirmed executing these indexes one-by-one fixes the problem. The commit will land soon.

If this is a production setup, its best to disable auto index creation in production due to the potential performance impact. You can grab the list of indexes from your Models schema like so: var indexes = YourModel.schema.indexes(), then follow the recommendations for creating them in production.

_FYI: in my testing MongoDB 2.4 doesn't have this limitation._

aheckmann on 2 Mar 2013

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