Delete old Indexer failures


We had a problem with the Elasticsearch Cluster, this was about two years ago. The problems resulted in approx 1.5 million indexer failures. The Index got allready deleted (retention), but the failures still exist. How can we get rid of them? We don’t need that info any longer and the API Call /api/system/indexer/failures show’s them all, which makes the API Call very slow.

I hope it’s pollible to get rid of them?

Best regards,

Hi Christoph,

there’s currently no way to delete them in the Graylog web interface but you can delete the documents in the index_failures collection in MongoDB.

See for details.

Hello Jochen,

Thanks for the quick reply! I can safely remove all the unneded entreis in the MongoDB colleciton index_failures? With graylog running or should I shut it down first?

Best regards,

You can remove them while Graylog is running.

Hello Jochen,

It’s not that easy …

> db.index_failures.remove({ index : "graylog2_8" })
        "nRemoved" : 0,
        "writeError" : {
                "code" : 20,
                "errmsg" : "cannot remove from a capped collection: graylog2.index_failures"

So, I had to dump the mongoDB, drop the index_failures and restore the index_failures colleciton without data:

Dump the collection
/usr/bin/mongodump --out /tmp/backup/ --host localhost --port 27017 --db graylog2 --collection index_failures --username <user>

Delte file

Drop Collection

Restore index_failures collection without data
/usr/bin/mongorestore --host localhost --port 27017 --db graylog2 --username <user> /tmp/backup/graylog2/

Now there are no Index failures any more visible on the Graylog Interface and the API.

Thanks for your help.

1 Like

Hi KeX,

did you have to stop or restart your graylog for and after restoring the index_failures?

Best regards,


Hello Arnaud,

No, I haven’t restarted graylog for this. In my case, one replica was corrupt. I just reduced the replicas to one and after that increased the replicas again.

Hope that helps.


mongo show error messages when I remove all documents:

Graylog:PRIMARY> db.index_failures.remove({})
“nRemoved” : 0,
“writeError” : {
“code” : 20,
“errmsg” : “cannot remove from a capped collection: graylog.index_failures”

Looks like the graylog.index_failures is a capped collection.