Flush failed with unexpected error.

Hi,

as part of the java-client integration test suite we do lots of flushes and bucket creations/removals. Things have been smooth sailing mostly, but we've known that flush has been "flaky" in the old days.

Now it came back with an interesting issue since 5.0. I think its been since 5.0 I haven't seen this error in the 4.x series if I remember correctly.

So randomly flush fails with

{"_":"Flush failed with unexpected error. Check server logs for details."}

and looking into the log it shows

Flushing "default" failed with error: 

{error,{flush_wait_failed,['ns_1@127.0.0.1'],[]}}

not sure if thats the root cause. I'll attach a cbcollectinfo, maybe you can draw conclusions from that and why its started in the 5.x timeframe?