Hello, When upgrading to 8.1.1 i took some time to quickly test this problem. Good news, is has disappeared, for me at least. I immediately reproduce it on a local 7.7 node, it died immediately. But it runs smoothly on the production 7.5, and local 8.1.1 node! The problem still exists in 8.0.0.
So i went through Lucene and Solr's CHANGELOG again but could not find any ticket about the problem? Does anyone have an idea which ticket could be responsible for fixing this? Anyway, many thanks! Markus -----Original message----- > From:Michael Gibney <mich...@michaelgibney.net> > Sent: Friday 22nd February 2019 17:22 > To: solr-user@lucene.apache.org > Subject: Re: Query of Death Lucene/Solr 7.6 > > Ah... I think there are two issues likely at play here. One is LUCENE-8531 > <https://issues.apache.org/jira/browse/LUCENE-8531>, which reverts a bug > related to SpanNearQuery semantics, causing possible query paths to be > enumarated up front. Setting ps=0 (although perhaps not appropriate for > some use cases) should address problems related to this issue. > > The other (likely affecting Gregg, for whom ps=0 did not help) is SOLR-12243 > <https://issues.apache.org/jira/browse/SOLR-12243>. Prior to 7.6, > SpanNearQuery (generated for relatively complex "graph" tokenized queries, > such as would be generated with WDGF, SynonymGraphFilter, etc.) were simply > getting dropped. This was surely a bug, in that pf did not contribute at > all to boosting such queries; but the silver lining was that performance > was great ;-) > > Markus, Gregg, could send examples (parsed query toString()) of problematic > queries (and perhaps relevant analysis chain configs)? > > Michael > > > > On Fri, Feb 22, 2019 at 11:00 AM Gregg Donovan <gregg...@gmail.com> wrote: > > > FWIW: we have also seen serious Query of Death issues after our upgrade to > > Solr 7.6. Are there any open issues we can watch? Is Markus' findings > > around `pf` our best guess? We've seen these issues even with ps=0. We also > > use the WDF. > > > > On Fri, Feb 22, 2019 at 8:58 AM Markus Jelsma <markus.jel...@openindex.io> > > wrote: > > > > > Hello Michael, > > > > > > Sorry it took so long to get back to this, too many things to do. > > > > > > Anyway, yes, we have WDF on our query-time analysers. I uploaded two log > > > files, both the same query of death with and without synonym filter > > enabled. > > > > > > https://mail.openindex.io/export/solr-8983-console.log 23 MB > > > https://mail.openindex.io/export/solr-8983-console-without-syns.log 1.9 > > MB > > > > > > Without the synonym we still see a huge number of entries. Many different > > > parts of our analyser chain contribute to the expansion of queries, but > > pf > > > itself really turns the problem on or off. > > > > > > Since SOLR-12243 is new in 7.6, does anyone know that SOLR-12243 could > > > have this side-effect? > > > > > > Thanks, > > > Markus > > > > > > > > > -----Original message----- > > > > From:Michael Gibney <mich...@michaelgibney.net> > > > > Sent: Friday 8th February 2019 17:19 > > > > To: solr-user@lucene.apache.org > > > > Subject: Re: Query of Death Lucene/Solr 7.6 > > > > > > > > Hi Markus, > > > > As of 7.6, LUCENE-8531 < > > > https://issues.apache.org/jira/browse/LUCENE-8531> > > > > reverted a graph/Spans-based phrase query implementation (introduced in > > > 6.5 > > > > -- LUCENE-7699 <https://issues.apache.org/jira/browse/LUCENE-7699>) to > > > an > > > > implementation that builds a separate phrase query for each possible > > > > enumerated path through the graph described by a parsed query. > > > > The potential for combinatoric explosion of the enumerated approach was > > > (as > > > > far as I can tell) one of the main motivations for introducing the > > > > Spans-based implementation. Some real-world use cases would be good to > > > > explore. Markus, could you send (as an attachment) the debug toString() > > > for > > > > the queries with/without synonyms enabled? I'm also guessing you may > > have > > > > WordDelimiterGraphFilter on the query analyzer? > > > > As an alternative to disabling pf, LUCENE-8531 only reverts to the > > > > enumerated approach for phrase queries where slop>0, so setting ps=0 > > > would > > > > probably also help. > > > > Michael > > > > > > > > On Fri, Feb 8, 2019 at 5:57 AM Markus Jelsma < > > markus.jel...@openindex.io > > > > > > > > wrote: > > > > > > > > > Hello (apologies for cross-posting), > > > > > > > > > > While working on SOLR-12743, using 7.6 on two nodes and 7.2.1 on the > > > > > remaining four, we stumbled upon a situation where the 7.6 nodes > > > quickly > > > > > succumb when a 'Query-of-Death' is issued, 7.2.1 up to 7.5 are all > > > > > unaffected (tested and confirmed). > > > > > > > > > > Following Smiley's suggestion i used Eclipse MAT to find the problem > > in > > > > > the heap dump i obtained, this fantastic tool revealed within minutes > > > that > > > > > a query thread ate 65 % of all resources, in the class variables i > > > could > > > > > find the the query, and reproduce the problem. > > > > > > > > > > The problematic query is 'dubbele dijk/rijke dijkproject in het > > > dijktracé > > > > > eemshaven-delfzijl', on 7.6 this input produces a 40+ MB toString() > > > output > > > > > in edismax' newFieldQuery. If the node survives it takes 2+ seconds > > > for the > > > > > query to run (150 ms otherwise). If i disable all query time > > > > > SynonymGraphFilters it still takes a second and produces just a 9 MB > > > > > toString() for the query. > > > > > > > > > > I could not find anything like this in Jira. I did think of > > LUCENE-8479 > > > > > and LUCENE-8531 but they were about graphs, this problem looked > > related > > > > > though. > > > > > > > > > > I think i tracked it further down to LUCENE-8589 or SOLR-12243. When > > i > > > > > leave Solr's edismax' pf parameter empty, everything runs fast. When > > > all > > > > > fields are configured for pf, the node dies. > > > > > > > > > > I am now unsure whether this is a Solr or a Lucene issue. > > > > > > > > > > Please let me know. > > > > > > > > > > Many thanks, > > > > > Markus > > > > > > > > > > ps. in Solr i even got an 'Impossible Exception', my first! > > > > > > > > > > > > > > >
