I agree this AlwaysForceMergePolicy is not working correctly. It's just a test I did to easily understand how MergeTrigger.MERGE_FINISHED was working.
Anyway my question is only about the MergeTrigger not present in the call to findForcedMerges(), to know if it is expected or inconsistent with the other find merges methods. Le lun. 20 juin 2022 à 14:26, Adrien Grand <[email protected]> a écrit : > Wouldn't this be a bug in the AlwaysForceMergePolicy, which should return > no merges if there is already a single segment with no deletes? > > On Mon, Jun 20, 2022 at 1:30 PM Bruno Roustant <[email protected]> > wrote: > >> If I use a simple "AlwaysForceMergePolicy" in a test, I can see that when >> a run IndexWriter.forceMerge(), the first call to >> AlwaysForceMergePolicy.findForcedMerges() is done for the >> MergeTrigger.EXPLICIT. But then, at IndexWriter.merge() line 4531, >> MergePolicy.findForcedMerges() is called with MergeTrigger.MERGE_FINISHED >> to merge the segments produced by the output of the first explicit forced >> merge, and so on. For this degenerated AlwaysForceMergePolicy, the test >> runs merges in an infinite loop. >> >> Le lun. 20 juin 2022 à 11:11, Adrien Grand <[email protected]> a écrit : >> >>> You seem to imply that `forceMerge` runs a cascaded merge where the >>> first merge creates some new segments that become inputs to a second merge. >>> Have you considered running a single merge? We had a discussion about >>> cascaded forced merges and TieredMergePolicy last year and ended up >>> changing `findForcedMerges` to never run cascaded merges: >>> https://issues.apache.org/jira/browse/LUCENE-7020. >>> >>> On Mon, Jun 20, 2022 at 10:31 AM Bruno Roustant < >>> [email protected]> wrote: >>> >>>> MergePolicy "find merges" methods take a MergeTrigger as parameter, >>>> except findForcedMerges() and findForcedDeletesMerges(). >>>> In my use-case, I could leverage a MergeTrigger in findForcedMerges(), >>>> which can be EXPLICIT or MERGE_FINISHED, to differentiate the merge >>>> selection between the initial explicit call and the subsequent calls >>>> triggered after the first merges. >>>> >>>> Should we add a MergeTrigger parameter to all MergePolicy "find merges" >>>> methods for consistency? >>>> If so, is it an internal or public API? (should this change stay in the >>>> main branch only) >>>> >>> >>> >>> -- >>> Adrien >>> >> > > -- > Adrien >
