[jira] [Commented] (LUCENE-9469) Use RandomMockMergePolicy more often

["Adrien Grand (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/LUCENE-9469?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17180601#comment-17180601 ] 

Adrien Grand commented on LUCENE-9469:
--------------------------------------

I think it has the potential to slow tests down significantly? If it doesn't +1 to do this change but otherwise we might need to make MockRandomMP find more reasonable merges as the index grows?

> Use RandomMockMergePolicy more often
> ------------------------------------
>
>                 Key: LUCENE-9469
>                 URL: https://issues.apache.org/jira/browse/LUCENE-9469
>             Project: Lucene - Core
>          Issue Type: Test
>            Reporter: Simon Willnauer
>            Priority: Major
>
> During the work on LUCENE-8962 we had some discussions about testability of the feature and how well we can guarantee that it's tested. One argument was that we can rely to a certain extend on the randomization and enabling these features by swapping in RandomMockMergePolicy. 
> I ran a test which throws an assertion error every time the feature is explicitly used which required MockRandomMergePolicy to be used. Unfortunately I had two entire test runs without any failure except of the tests that explicitly enabled it ie. the ones that I wrote for the feature. 
> I think we are not using this MP often enough in our tests and I want to propose to use it way more frequently. It's certainly not a replacement for dedicated unit tests, I wrote a dedicated one for every random failure I found which should be common practice but it would be great to increase coverage by swapping in MockRandomMergePolicy more often. Maybe something as simple as this would do it:
> {noformat}
> --- a/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java
> +++ b/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java
> @@ -1059,7 +1059,7 @@ public abstract class LuceneTestCase extends Assert {
>    }
>  
>    public static MergePolicy newMergePolicy(Random r, boolean includeMockMP) {
> -    if (includeMockMP && rarely(r)) {
> +    if (includeMockMP && r.nextBoolean()) {
>        return new MockRandomMergePolicy(r);
>      } else if (r.nextBoolean()) {
>        return newTieredMergePolicy(r);
> {noformat}



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@lucene.apache.org
For additional commands, e-mail: issues-help@lucene.apache.org