Mondump failure: “error dumping metadata”

[Niicck]

I hope someone can help me identify what's going on. My remote mongodump backup script worked for months until today. I'm suddenly getting this error:

Failed: error dumping metadata: error converting index (<nil>): conversion of BSON value '2' of type 'bson.Decimal128' not supported

mongodump does not work on my remote backup server. However, when I run mongodump on the server when my production database lives, it works. But both servers use the exact same version of mongodump:

mongodump version: r3.4.1 git version: 5e103c4f5583e2566a45d740225dc250baacfbd7 Go version: go1.7 os: linux arch: amd64 compiler: gc

The only place I've found any reference to this error is a Chinese blog (http://blog.5ibc.net/p/102326.html). However, their problem was that they were using an old version of mongo.

Does anyone know what went wrong or how to fix this?

[gabriel russell]

Niicck,

Can you run db.collectionName.getIndexes() on affected collection, and show the results here?

I don't know where the NumberDecimal value is showing up in your index. I just made a guess that it could be in the partialFilterExpression and did a test creating a partialFilterExpression index with a numberDecimal, and was able to dump it properly with mongodump 3.4. Also, I tried an old version of mongodump that I assumed would not work, and I got a different error then you got. mongodump 3.3.4 ( a development version that predates the NumberDecimal work ) and this is what I got:

2017-04-19T17:30:36.640-0400    Failed: error dumping metadata: error running `listIndexes`. Collection: `test.foo` Err: Unknown element kind (0x13)

Thanks,

Gabriel