Deleted Keys still around after reboot/compaction?


#1

Hey,

i just ran into a Problem i do not quiet understand why it is happening.
The “Documents”-View in the CouchbaseConsole takes about 30 Seconds to load and results in “Error: (unexpected)”. Within those 30 Seconds the Server goes crazy and looks up about 2000 Operations per Second. Screenshot of the Bucket at that time: http://i.imgur.com/KEZlMvd.png

Reproduction:
Add some (15) filler docs (a:1 to a:15) to have the “Documents”-View in the CouchbaseConsole filled.
Add some (5) filler docs (z:1 to z:5) to have some Docs at the “End” of the Bucket
Add 100.000 docs named “test:{number}” to the Bucket.
Wait for Indexing/Rebalancing
Remove the 100.000 documents named “test:{number}” from the Bucket.
Wait for Indexing/Rebalancing (Additionally reboot Couchbase or even the Root)

The bucket should now be bugged and result in a “Error: (unexpected)” as soon as you hit the first deleted key in the “Documents”-View by either using “NextPage” or “Show 100 Docs”.

Can someone explain how this is happening? Are there “empty slots” in the Tree and CB interates trough all of the empty slots? Why wont they be rebalanced/merged?

(Compacting the Bucket with only 27 Items takes about 60 Seconds in that state; Slow Root Atom N2800)

Edit: Changing the Bucket to Full Eviction reduces the lookup-speed of the non-existing keys to 700-800/s instead of the ~2000 mentioned above in Value Eviction. Im assuming the Documents-View does not use any indexing and looks for keys by their internal ID and does not follow a tree-path? Thats the only way i could imagine this problem happening.

Thanks,
Kademlia