Whilst testing out Kopia using S3 as the repository storage, my colleague was presented with the following error message:
Found too many index blobs (133), this may result in degraded performance.
Is anyone able to provide some background on this message, please?
Kopia builds its index by scanning and merging blobs that start n prefix in the store. It will also regularly perform compaction that merges smaller index blobs into larger ones so things should be kept in balance and on average there should be reasonably small number of blobs.
If you’re taking snapshots very frequently or maintenance has not run for a while, you will have lots of uncompacted blobs and you may see this warning. The warning is arbitrarily set at 100, which is probably and we’ll adjust it upwards in Kopia.
If this is bothering you much, you can adjust the frequency of maintenance jobs with:
kopia maintenance set --quick-interval 30m
or something similar. But again, other than scary warning there are no ill effects of this.