(accumulo) branch main updated: tacks number of accesses to zoocache entry for logging (#5156)

[kturner]

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kturner pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/accumulo.git


The following commit(s) were added to refs/heads/main by this push:
     new 6dc52bc4ee tacks number of accesses to zoocache entry for logging 
(#5156)
6dc52bc4ee is described below

commit 6dc52bc4ee703cac23921dc61705c45b6734f93c
Author: Keith Turner <ktur...@apache.org>
AuthorDate: Mon Dec 9 18:39:36 2024 -0500

    tacks number of accesses to zoocache entry for logging (#5156)
    
    Adds an access count to the trace logging when a zoocache entry is
    removed because it was not used recently.  This will help find data that
    is being stored in zoocache and accessed infrequently which may cause
    uneedd watches.
---
 .../java/org/apache/accumulo/core/fate/zookeeper/ZcNode.java     | 9 +++++++++
 .../java/org/apache/accumulo/core/fate/zookeeper/ZooCache.java   | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git 
a/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZcNode.java 
b/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZcNode.java
index bcd2b93872..d4ed3c955b 100644
--- a/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZcNode.java
+++ b/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZcNode.java
@@ -20,6 +20,7 @@ package org.apache.accumulo.core.fate.zookeeper;
 
 import java.util.List;
 import java.util.Objects;
+import java.util.concurrent.atomic.AtomicLong;
 
 import com.google.common.base.Preconditions;
 
@@ -52,6 +53,8 @@ class ZcNode {
 
   static final ZcNode NON_EXISTENT = new ZcNode();
 
+  private final AtomicLong accessCount = new AtomicLong(0);
+
   private ZcNode() {
     this.data = null;
     this.stat = null;
@@ -96,6 +99,7 @@ class ZcNode {
    */
   byte[] getData() {
     Preconditions.checkState(cachedData());
+    accessCount.incrementAndGet();
     return data;
   }
 
@@ -116,6 +120,7 @@ class ZcNode {
    */
   List<String> getChildren() {
     Preconditions.checkState(cachedChildren());
+    accessCount.incrementAndGet();
     return children;
   }
 
@@ -139,4 +144,8 @@ class ZcNode {
   boolean notExists() {
     return stat == null && data == null && children == null;
   }
+
+  public long getAccessCount() {
+    return accessCount.get();
+  }
 }
diff --git 
a/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZooCache.java 
b/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZooCache.java
index ae8e752b20..596037c1de 100644
--- a/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZooCache.java
+++ b/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZooCache.java
@@ -181,7 +181,8 @@ public class ZooCache {
     this.externalWatcher = watcher;
     RemovalListener<String,ZcNode> removalListerner = (path, zcNode, reason) 
-> {
       try {
-        log.trace("{} removing watches for {} because {}", cacheId, path, 
reason);
+        log.trace("{} removing watches for {} because {} accesses {}", 
cacheId, path, reason,
+            zcNode == null ? -1 : zcNode.getAccessCount());
         reader.getZooKeeper().removeWatches(path, ZooCache.this.watcher, 
Watcher.WatcherType.Any,
             false);
       } catch (InterruptedException | KeeperException | RuntimeException e) {