Merge pull request #3952 from andreitokar/issue-3909

Prevent non-stop page rewriting within an idle database
h2database · Dec 22, 2023 · 3525a20 · 3525a20
2 parents 97fd15c + 0cc81db
commit 3525a20
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/h2/src/main/org/h2/mvstore/MVStore.java b/h2/src/main/org/h2/mvstore/MVStore.java
@@ -123,7 +123,7 @@ to a map (possibly the metadata map) -
 /**
  * A persistent storage for maps.
  */
-public class MVStore implements AutoCloseable {
+public final class MVStore implements AutoCloseable {
 
     /**
      * Store is open.
@@ -1265,8 +1265,8 @@ void beforeWrite(MVMap<?, ?> map) {
                 fileStore.isRegularMap(map)) {
             saveNeeded = false;
             // check again, because it could have been written by now
-            if (autoCommitMemory > 0 && needStore()) {
-                // if unsaved memory creation rate is to high,
+            if (needStore()) {
+                // if unsaved memory creation rate is too high,
                 // some back pressure need to be applied
                 // to slow things down and avoid OOME
                 if (requireStore() && !map.isSingleWriter()) {

diff --git a/h2/src/main/org/h2/mvstore/RandomAccessStore.java b/h2/src/main/org/h2/mvstore/RandomAccessStore.java
@@ -43,7 +43,7 @@ public abstract class RandomAccessStore extends FileStore<SFChunk>
 
     private long reservedLow;
     private long reservedHigh;
-
+    private boolean stopIdleHousekeeping;
 
     public RandomAccessStore(Map<String, Object> config) {
         super(config);
@@ -702,10 +702,13 @@ private void shrinkIfPossible(int minPercent) {
 
     @Override
     protected void doHousekeeping(MVStore mvStore) throws InterruptedException {
+        boolean idle = isIdle();
+        if (idle && stopIdleHousekeeping) {
+            return;
+        }
         int autoCommitMemory = mvStore.getAutoCommitMemory();
         int fillRate = getFillRate();
         if (isFragmented() && fillRate < getAutoCompactFillRate()) {
-
             mvStore.tryExecuteUnderStoreLock(() -> {
                 int moveSize = 2 * autoCommitMemory;
                 if (isIdle()) {
@@ -731,6 +734,7 @@ protected void doHousekeeping(MVStore mvStore) throws InterruptedException {
                 return true;
             });
         }
+        stopIdleHousekeeping = idle && getFillRate() <= fillRate && getRewritableChunksFillRate() <= chunksFillRate;
     }
 
     private int getTargetFillRate() {