HIVE-16233 : llap: Query failed with AllocatorOutOfMemoryException (S…

…ergey Shelukhin, reviewed by Prasanth Jayachandran and Gopal Vijayaraghavan)

common/src/java/org/apache/hadoop/hive/conf/HiveConf.java

@@ -2963,7 +2963,7 @@ public static enum ConfVars {
         "LLAP IO memory usage; 'cache' (the default) uses data and metadata cache with a\n" +
         "custom off-heap allocator, 'none' doesn't use either (this mode may result in\n" +
         "significant performance degradation)"),
-    LLAP_ALLOCATOR_MIN_ALLOC("hive.llap.io.allocator.alloc.min", "256Kb", new SizeValidator(),
+    LLAP_ALLOCATOR_MIN_ALLOC("hive.llap.io.allocator.alloc.min", "16Kb", new SizeValidator(),
         "Minimum allocation possible from LLAP buddy allocator. Allocations below that are\n" +
         "padded to minimum allocation. For ORC, should generally be the same as the expected\n" +
         "compression buffer size, or next lowest power of 2. Must be a power of 2."),
@@ -2990,6 +2990,14 @@ public static enum ConfVars {
     LLAP_ALLOCATOR_MAPPED_PATH("hive.llap.io.allocator.mmap.path", "/tmp",
         new WritableDirectoryValidator(),
         "The directory location for mapping NVDIMM/NVMe flash storage into the ORC low-level cache."),
+    LLAP_ALLOCATOR_DISCARD_METHOD("hive.llap.io.allocator.discard.method", "both",
+        new StringSet("freelist", "brute", "both"),
+        "Which method to use to force-evict blocks to deal with fragmentation:\n" +
+        "freelist - use half-size free list (discards less, but also less reliable); brute -\n" +
+        "brute force, discard whatever we can; both - first try free list, then brute force."),
+    LLAP_ALLOCATOR_DEFRAG_HEADROOM("hive.llap.io.allocator.defrag.headroom", "1Mb",
+        "How much of a headroom to leave to allow allocator more flexibility to defragment.\n" +
+        "The allocator would further cap it to a fraction of total memory."),
     LLAP_USE_LRFU("hive.llap.io.use.lrfu", true,
         "Whether ORC low-level cache should use LRFU cache policy instead of default (FIFO)."),
     LLAP_LRFU_LAMBDA("hive.llap.io.lrfu.lambda", 0.01f,