14 Aug 2009
Today I found some queries were erroring with:
XDMP-LISTCACHEFULL: List cache full on host …
Googling “LISTCACHEFULL” returns a paltry 1 result – someone asking about the error on the MarkLogic mailing list but getting no response. Great.
I simplified the query down to the part causing the error:
cts:search( fn:doc(), cts:element-query( fn:expanded-QName("http://www.springer.com/app/meta", "OrgName"), cts:word-query("university of exeter", ("unstemmed")) ) )
Nothing really complex about that query – but playing around with it, I found that changing “unstemmed” to “stemmed” fixed it. I have no idea why an unstemmed query causes more trouble than a stemmed query which has much more work to do. Changing to a stemmed query wasn’t an option because that would limit the search to content in one language (see this post for more details on this weird behaviour).
Then the error was magically gone after a restart of the MarkLogic service. The classic ‘switch it off and on again’ fix. Although it’s a relief the problem is gone, it’s also really frustrating because it’s hard to carry on investigating the cause without being able to reproduce the error, and I just know it will come back again at some unknown point in the future. If I ever do get to the bottom of it I’ll post an update…