From 53fff0034ffe8b5b7ac51dca40cbb2298757eab8 Mon Sep 17 00:00:00 2001
From: Mick Semb Wever <mck@apache.org>
Date: Sat, 7 Dec 2024 14:16:35 +0400
Subject: [PATCH] Further Improve debug around paused and disabled compaction

 patch by Mick Semb Wever; reviewed by Paulo Motta for CASSANDRA-19728
---
 CHANGES.txt                                   |  1 +
 .../cassandra/db/ColumnFamilyStore.java       | 32 +++++++++++++++----
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index 1841ef66be..9e31f5ea19 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 5.1
+ * Improve debug around paused and disabled compaction (CASSANDRA-20131,CASSANDRA-19728)
  * DiskUsageBroadcaster does not update usageInfo on node replacement (CASSANDRA-21033)
  * Reject PrepareJoin if tokens are already assigned (CASSANDRA-21006)
  * Don't update registration status if node state for decommissioned peer is found with the same address (CASSANDRA-21005)
diff --git a/src/java/org/apache/cassandra/db/ColumnFamilyStore.java b/src/java/org/apache/cassandra/db/ColumnFamilyStore.java
index 839a21d55d..4cc2615cd4 100644
--- a/src/java/org/apache/cassandra/db/ColumnFamilyStore.java
+++ b/src/java/org/apache/cassandra/db/ColumnFamilyStore.java
@@ -65,6 +65,7 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
+import org.apache.commons.lang3.exception.ExceptionUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -2664,7 +2665,6 @@ public class ColumnFamilyStore implements ColumnFamilyStoreMBean, Memtable.Owner
         // and so we only run one major compaction at a time
         synchronized (this)
         {
-            logger.debug("Cancelling in-progress compactions for {}", metadata.name);
             Iterable<ColumnFamilyStore> toInterruptFor = interruptIndexes
                                                          ? concatWithIndexes()
                                                          : Collections.singleton(this);
@@ -2675,6 +2675,9 @@ public class ColumnFamilyStore implements ColumnFamilyStoreMBean, Memtable.Owner
 
             Iterable<TableMetadata> toInterruptForMetadata = Iterables.transform(toInterruptFor, ColumnFamilyStore::metadata);
 
+            logger.debug("Cancelling in-progress compactions for {}.{} ({}) {}", metadata.keyspace, metadata.name,
+                         debugToInterruptFor(toInterruptFor), onelinerStackTrace(new Throwable()));
+
             try (CompactionManager.CompactionPauser pause = CompactionManager.instance.pauseGlobalCompaction();
                  CompactionManager.CompactionPauser pausedStrategies = pauseCompactionStrategies(toInterruptFor))
             {
@@ -2700,13 +2703,11 @@ public class ColumnFamilyStore implements ColumnFamilyStoreMBean, Memtable.Owner
                 {
                     if (cfs.getTracker().getCompacting().stream().anyMatch(sstablesPredicate))
                     {
-                        logger.warn("Unable to cancel in-progress compactions for {}. " +
-                                    "Perhaps there is an unusually large row in progress somewhere, or the system is simply overloaded.",
-                                    metadata.name);
+                        logger.warn("Unable to cancel in-progress compactions for {}.{}.  Perhaps there is an unusually large row in progress somewhere, or the system is simply overloaded.", metadata.keyspace, metadata.name);
                         return null;
                     }
                 }
-                logger.trace("Compactions successfully cancelled");
+                logger.debug("Compactions successfully cancelled for {}.{}", metadata.keyspace, metadata.name);
 
                 // run our task
                 try
@@ -2761,7 +2762,26 @@ public class ColumnFamilyStore implements ColumnFamilyStoreMBean, Memtable.Owner
         return accumulate;
     }
 
-    public <T> T withAllSSTables(final OperationType operationType, Function<LifecycleTransaction, T> op)
+    private static String debugToInterruptFor(Iterable<ColumnFamilyStore> toInterruptFor)
+    {
+        StringBuilder debug = new StringBuilder();
+        for (ColumnFamilyStore cfs : toInterruptFor)
+            debug.append(cfs.getKeyspaceName()).append('.').append(cfs.getTableName()).append(',');
+        debug.setLength(debug.length() - 1);
+        return debug.toString();
+    }
+
+    private static String onelinerStackTrace(Throwable t)
+    {
+        return ExceptionUtils.getStackTrace(t)
+            .replace("java.lang.Throwable", "")
+            .replaceAll("at org[.]apache[.]cassandra[.]", "at ..")
+            .replaceAll("at [a-z].+\n", "")
+            .replaceAll("\n|\t", " ")
+            .replaceAll(" +", " ");
+     }
+
+public <T> T withAllSSTables(final OperationType operationType, Function<LifecycleTransaction, T> op)
     {
         Callable<LifecycleTransaction> callable = () -> {
             assert data.getCompacting().isEmpty() : data.getCompacting();