Difficult for me to understand

On 03/02/26 10:18, Marco Lettere wrote: > Hi Christian and all, > > I'm experiencing a weird issue with a RestXQ service of mine which was > working and suddenly starts having problems because it just stops > serving requests. > > I know about SSCE and so on but this time it's hard to reproduce. > Shortly, it receives about 5 simultaneous requests and for each of > those it calls one xquery:fork-join (5 functions) to query another > service. > > I cannot say what the error is exactly during the time when it is > stuck. What I can see on the client are, besides HTTP 503 and Read > Timeouts, the following logs which appear frequently but with no > particular order: > > ERROR: Unexpected error: java.lang.NullPointerException: Cannot invoke > "org.basex.util.hash.WeakTokenSet$WeakTokenRef.get()" because > "this.keys[index]" is null (hint: > /...y/webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > ERROR: Unexpected error: java.lang.ArrayIndexOutOfBoundsException > (hint: > /.../webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > ERROR: Unexpected error: java.lang.ArrayIndexOutOfBoundsException: > Index 8 out of bounds for length 8 (hint: > /.../webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > Line and column numbers point always to the same xquery:fork-join call. > > Can you point me to what I should investigate? Am I hitting some > quantitative limit on concurrency? Connections? > > Thank you for any help because I'm currently wandering in the darkness > :-) > > Regards, > > Marco. >

Von: Marco Lettere via BaseX-Talk <basex-talk at mailman.uni-konstanz.de> Gesendet: Dienstag, 3. Februar 2026 10:29 An: basex-talk at mailman.uni-konstanz.de <basex-talk at mailman.uni-konstanz.de> Betreff: [basex-talk] Re: Difficult for me to understand Oops, forgot to mention that meanwhile I moved from 11.7 to 12.1. Sorry. On 03/02/26 10:18, Marco Lettere wrote: > Hi Christian and all, > > I'm experiencing a weird issue with a RestXQ service of mine which was > working and suddenly starts having problems because it just stops > serving requests. > > I know about SSCE and so on but this time it's hard to reproduce. > Shortly, it receives about 5 simultaneous requests and for each of > those it calls one xquery:fork-join (5 functions) to query another > service. > > I cannot say what the error is exactly during the time when it is > stuck. What I can see on the client are, besides HTTP 503 and Read > Timeouts, the following logs which appear frequently but with no > particular order: > > ERROR: Unexpected error: java.lang.NullPointerException: Cannot invoke > "org.basex.util.hash.WeakTokenSet$WeakTokenRef.get()" because > "this.keys[index]" is null (hint: > /...y/webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > ERROR: Unexpected error: java.lang.ArrayIndexOutOfBoundsException > (hint: > /.../webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > ERROR: Unexpected error: java.lang.ArrayIndexOutOfBoundsException: > Index 8 out of bounds for length 8 (hint: > /.../webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > Line and column numbers point always to the same xquery:fork-join call. > > Can you point me to what I should investigate? Am I hitting some > quantitative limit on concurrency? Connections? > > Thank you for any help because I'm currently wandering in the darkness > :-) > > Regards, > > Marco. >

On 03/02/26 10:35, Christian Grün wrote: > Hi Marco, > > It’s just an assumption, but your problem could be related to a known > xquery:fork-join bug that became effective with BaseX 12.0 and JDK 17 > [1]. We are working on it, but I cannot give a timeline yet. > > You can try to minimize the code that is contained in the fork-join > function. For example, code like… > > xquery:fork-join( > for $i in 1 to 100 > return fn() { > let $url := "http://xyz.com/" || $i > return doc($url) > } > ) > > …could be simplified to: > > let $urls := ( > for $i in 1 to 100 > return "http://xyz.com/" || $i > ) > return xquery:fork-join( > for $url in $urls > return fn() { doc($url) } > ) > > Hope this helps; please follow the referenced GitHub issue to track > the progress. > Christian > > [1] https://github.com/BaseXdb/basex/issues/2479 > ------------------------------------------------------------------------ > *Von:* Marco Lettere via BaseX-Talk <basex-talk at mailman.uni-konstanz.de> > *Gesendet:* Dienstag, 3. Februar 2026 10:29 > *An:* basex-talk at mailman.uni-konstanz.de > <basex-talk at mailman.uni-konstanz.de> > *Betreff:* [basex-talk] Re: Difficult for me to understand > Oops, forgot to mention that meanwhile I moved from 11.7 to 12.1. > > Sorry. > > > On 03/02/26 10:18, Marco Lettere wrote: > > Hi Christian and all, > > > > I'm experiencing a weird issue with a RestXQ service of mine which was > > working and suddenly starts having problems because it just stops > > serving requests. > > > > I know about SSCE and so on but this time it's hard to reproduce. > > Shortly, it receives about 5 simultaneous requests and for each of > > those it calls one xquery:fork-join (5 functions) to query another > > service. > > > > I cannot say what the error is exactly during the time when it is > > stuck. What I can see on the client are, besides HTTP 503 and Read > > Timeouts, the following logs which appear frequently but with no > > particular order: > > > > ERROR: Unexpected error: java.lang.NullPointerException: Cannot invoke > > "org.basex.util.hash.WeakTokenSet$WeakTokenRef.get()" because > > "this.keys[index]" is null (hint: > > /...y/webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > > > ERROR: Unexpected error: java.lang.ArrayIndexOutOfBoundsException > > (hint: > > /.../webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > > > ERROR: Unexpected error: java.lang.ArrayIndexOutOfBoundsException: > > Index 8 out of bounds for length 8 (hint: > > /.../webapp/nubisware.muscle.fiber.ccp_admin/ccp_worker_sk.xqm@65:33) > > > > Line and column numbers point always to the same xquery:fork-join call. > > > > Can you point me to what I should investigate? Am I hitting some > > quantitative limit on concurrency? Connections? > > > > Thank you for any help because I'm currently wandering in the darkness > > :-) > > > > Regards, > > > > Marco. > >