params adjust

Author: albertzaharovits

server/src/main/java/org/elasticsearch/index/engine/ThreadPoolMergeExecutorService.java

@@ -87,8 +87,8 @@ public class ThreadPoolMergeExecutorService {
     private ThreadPoolMergeExecutorService(ThreadPool threadPool) {
         this.executorService = threadPool.executor(ThreadPool.Names.MERGE);
         this.maxConcurrentMerges = threadPool.info(ThreadPool.Names.MERGE).getMax();
-        this.concurrentMergesFloorLimitForThrottling = maxConcurrentMerges * 2;
-        this.concurrentMergesCeilLimitForThrottling = maxConcurrentMerges * 4;
+        this.concurrentMergesFloorLimitForThrottling = 2;
+        this.concurrentMergesCeilLimitForThrottling = maxConcurrentMerges * 2;
     }
 
     boolean submitMergeTask(MergeTask mergeTask) {
@@ -230,10 +230,10 @@ private static long newTargetIORateBytesPerSec(
             );
         } else if (currentlySubmittedIOThrottledMergeTasks > concurrentMergesCeilLimitForThrottling
             && currentTargetIORateBytesPerSec < MAX_IO_RATE.getBytes()) {
-                // increase target IO rate by 10% (capped)
+                // increase target IO rate by 20% (capped)
                 newTargetIORateBytesPerSec = Math.min(
                     MAX_IO_RATE.getBytes(),
-                    currentTargetIORateBytesPerSec + currentTargetIORateBytesPerSec / 10L
+                    currentTargetIORateBytesPerSec + currentTargetIORateBytesPerSec / 20L
                 );
             } else {
                 newTargetIORateBytesPerSec = currentTargetIORateBytesPerSec;