Github user vrozov commented on a diff in the pull request: https://github.com/apache/drill/pull/965#discussion_r143593333 --- Diff: exec/java-exec/src/main/java/org/apache/drill/exec/store/schedule/BlockMapBuilder.java --- @@ -104,12 +104,16 @@ public BlockMapReader(FileStatus status, boolean blockify) { @Override protected List<CompleteFileWork> runInner() throws Exception { final List<CompleteFileWork> work = Lists.newArrayList(); + + final Set<String> noDrillbitHosts = logger.isDebugEnabled() ? Sets.<String>newHashSet() : null; --- End diff -- Consider moving `noDillbitHosts` to `BlockMapBuilder` class (use `Sets.newConcurrentHashSet()` in this case) as it does not seem to belong to `BlockMapReader`. With such change, other changes are not necessary and likely this will allow reducing repeated log messages even further. Drop `<Sring>` from `Sets.<String>newHashSet()`.
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