I am implementing a batch processing that needs to execute a high number of search queries in MarkLogic to find the documents to be modified. The query which I am using looks like this:
cts:search(/ch:haufe-document,
cts:and-query((
cts:element-range-query(fn:QName("http://idesk.haufe-lexware.com/document-meta","rootId"), "=", xs:string($root-id)),
cts:element-range-query(fn:QName("http://contenthub.haufe-lexware.com/haufe-document","application"), "=", xs:string($APPLICATION-ID))
))
)
The $root-id will be different for each query, the $APPLICATION-ID is a constant value. Usually these queries return a small number of documents (less than 10), sometimes up to 150, but they still work fine. Only when many of such queries are executed in a row (could be more than 100000 for one batch job) at some point I get back an error like this:
XDMP-EXPNTREECACHEFULL: cts:search(fn:collection()/ch:haufe-document, cts:and-query((cts:element-range-query(fn:QName("http://idesk.haufe-lexware.com/document-meta","rootId"), "=", "HI14429659", ("collation=http://marklogic.com/collation/"), 1), cts:element-range-query(fn:QName("http://contenthub.haufe-lexware.com/haufe-document","application"), "=", "idesk", ("collation=http://marklogic.com/collation/"), 1)), ())) -- Expanded tree cache full on host some-host.cloudapp.net uri /content/idesk/c9103265-0a44-496b-b2b1-617b0b042208/HI14429659.xml
When I execute the same query manually it runs without problem and returns very few results (just one in most cases). The number of documents matching /ch:haufe-document is about 3 million, but does not change much during the processing (the documents are only modified). The database contains additional 1.5 million documents with meta data, these documents are added during the processing.
The strange thing is that the first two batch jobs, each processing >600000 documents, worked fine. But the third job failed with the error above and since then only very small jobs (~30000 docs) can be processed successfully.
I already tried to increase the size of the expanded tree cache, but it didn't help. I also tried an "unfiltered" search, but the error stays.
I would appreciate any hint to what the problem could be.
Update: One thing I didn't mention, because I didn't realize it might be relevant is this: The whole process is implemented as a REST extension, which is called from a Java application. A POST request is made which contains an XML with a list of document IDs to be processed. And this list can be very long (>100000 entries).
The solution I found is this: I modified the Java application such that it does not send all data to MarkLogic at once, but split it up into chunks of 10000 IDs. Now the error is gone. The downside is that the change is now done in several transactions, so the modifications become visible before everything is done. But for my usecase this is acceptable.