From e3064f77734922b8f06dd3b9380dd8203b6b9bf3 Mon Sep 17 00:00:00 2001
From: Henning Andersen <henning.andersen@elastic.co>
Date: Fri, 26 Jan 2024 09:16:51 +0100
Subject: [PATCH] Add decay time logging

---
 .../blobcache/shared/SharedBlobCacheService.java            | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/x-pack/plugin/blob-cache/src/main/java/org/elasticsearch/blobcache/shared/SharedBlobCacheService.java b/x-pack/plugin/blob-cache/src/main/java/org/elasticsearch/blobcache/shared/SharedBlobCacheService.java
index f89285ae61cc0..cecd03265e068 100644
--- a/x-pack/plugin/blob-cache/src/main/java/org/elasticsearch/blobcache/shared/SharedBlobCacheService.java
+++ b/x-pack/plugin/blob-cache/src/main/java/org/elasticsearch/blobcache/shared/SharedBlobCacheService.java
@@ -1548,7 +1548,11 @@ public boolean maybeEvictLeastUsed() {
         }
 
         private void computeDecay() {
+            long now = System.currentTimeMillis();
+            long afterLock;
+            long end;
             synchronized (SharedBlobCacheService.this) {
+                afterLock = System.currentTimeMillis();
                 appendLevel1ToLevel0();
                 for (int i = 2; i < maxFreq; i++) {
                     assert freqs[i - 1] == null;
@@ -1558,6 +1562,8 @@ private void computeDecay() {
                     assert freqs[i - 1] == null || invariant(freqs[i - 1], true);
                 }
             }
+            end = System.currentTimeMillis();
+            logger.info("Decay took {} ms (acquire lock: {} ms)", end-now, afterLock-now);
         }
 
         class DecayAndNewEpochTask extends AbstractRunnable {