h2database · katzyn · Jul 22, 2023 · Jul 22, 2023
diff --git a/h2/src/docsrc/html/features.html b/h2/src/docsrc/html/features.html
@@ -549,7 +549,7 @@ <h3>Delayed Database Closing</h3>
 <h3 id="do_not_close_on_exit">Don't Close a Database when the VM Exits</h3>
 <p>
 By default, a database is closed when the last connection is closed. However, if it is never closed,
-the database is closed when the virtual machine exits normally, using a shutdown hook.
+a persistent database is closed when the virtual machine exits normally, using a shutdown hook.
 In some situations, the database should not be closed in this case, for example because the
 database is still used at virtual machine shutdown (to store the shutdown process in the database for example).
 For those cases, the automatic closing of the database can be disabled in the database URL.
@@ -560,6 +560,10 @@ <h3 id="do_not_close_on_exit">Don't Close a Database when the VM Exits</h3>
 <pre>
 String url = "jdbc:h2:~/test;DB_CLOSE_ON_EXIT=FALSE";
 </pre>
+<b>Warning:</b> when database closing on exit is disabled, an application <b>must</b> execute the
+<a href="commands.html#shutdown">SHUTDOWN</a> command by itself in its own shutdown hook
+after completion of all operations with database to avoid data loss
+and should not try to establish new connections to database after that.
 
 <h2 id="execute_sql_on_connection">Execute SQL on Connection</h2>
 <p>

diff --git a/h2/src/main/org/h2/engine/ConnectionInfo.java b/h2/src/main/org/h2/engine/ConnectionInfo.java
@@ -119,6 +119,7 @@ public ConnectionInfo(String u, Properties info, String user, Object password) {
         String[] commonSettings = { //
                 "ACCESS_MODE_DATA", "AUTO_RECONNECT", "AUTO_SERVER", "AUTO_SERVER_PORT", //
                 "CACHE_TYPE", //
+                "DB_CLOSE_ON_EXIT", //
                 "FILE_LOCK", //
                 "JMX", //
                 "NETWORK_TIMEOUT", //

diff --git a/h2/src/main/org/h2/engine/Database.java b/h2/src/main/org/h2/engine/Database.java
@@ -189,6 +189,7 @@ public final class Database implements DataHandler, CastDataProvider {
     private int maxOperationMemory =
             Constants.DEFAULT_MAX_OPERATION_MEMORY;
     private SmallLRUCache<String, String[]> lobFileListCache;
+    private final boolean closeAtVmShutdown;
     private final boolean autoServerMode;
     private final int autoServerPort;
     private Server server;
@@ -268,7 +269,12 @@ public Database(ConnectionInfo ci, String cipher) {
             javaObjectSerializerName = s;
         }
         this.allowBuiltinAliasOverride = ci.getProperty("BUILTIN_ALIAS_OVERRIDE", false);
-        boolean closeAtVmShutdown = dbSettings.dbCloseOnExit;
+        if (autoServerMode && (readOnly || !persistent || fileLockMethod == FileLockMethod.NO
+                || fileLockMethod == FileLockMethod.FS)) {
+            throw DbException.getUnsupportedException(
+                    "AUTO_SERVER=TRUE && (readOnly || inMemory || FILE_LOCK=NO || FILE_LOCK=FS)");
+        }
+        closeAtVmShutdown = ci.getProperty("DB_CLOSE_ON_EXIT", persistent);
         if (autoServerMode && !closeAtVmShutdown) {
             throw DbException.getUnsupportedException("AUTO_SERVER=TRUE && DB_CLOSE_ON_EXIT=FALSE");
         }
@@ -299,11 +305,6 @@ public Database(ConnectionInfo ci, String cipher) {
         trace = traceSystem.getTrace(Trace.DATABASE);
         trace.info("opening {0} (build {1})", databaseName, Constants.BUILD_ID);
         try {
-            if (autoServerMode && (readOnly || !persistent || fileLockMethod == FileLockMethod.NO
-                    || fileLockMethod == FileLockMethod.FS)) {
-                throw DbException.getUnsupportedException(
-                        "AUTO_SERVER=TRUE && (readOnly || inMemory || FILE_LOCK=NO || FILE_LOCK=FS)");
-            }
             if (persistent) {
                 String lockFileName = databaseName + Constants.SUFFIX_LOCK_FILE;
                 if (readOnly) {
@@ -379,7 +380,7 @@ public Database(ConnectionInfo ci, String cipher) {
                 int writeDelay = ci.getProperty("WRITE_DELAY", Constants.DEFAULT_WRITE_DELAY);
                 setWriteDelay(writeDelay);
             }
-            if (closeAtVmShutdown) {
+            if (closeAtVmShutdown || persistent) {
                 OnExitDatabaseCloser.register(this);
             }
         } catch (Throwable e) {
@@ -1069,7 +1070,7 @@ public synchronized void removeSession(SessionLocal session) {
         if (isUserSession(session)) {
             if (userSessions.isEmpty()) {
                 if (closeDelay == 0) {
-                    close(false);
+                    close();
                 } else if (closeDelay < 0) {
                     return;
                 } else {
@@ -1132,13 +1133,31 @@ private synchronized void closeAllSessionsExcept(SessionLocal except) {
         }
     }
 
+    /**
+     * Close the database.
+     */
+    void close() {
+        close(false);
+    }
+
+    /**
+     * Invoked by shutdown hook.
+     */
+    void onShutdown() {
+        if (closeAtVmShutdown) {
+            close(true);
+        } else if (persistent) {
+            checkpoint();
+        }
+    }
+
     /**
      * Close the database.
      *
      * @param fromShutdownHook true if this method is called from the shutdown
      *            hook
      */
-    void close(boolean fromShutdownHook) {
+    private void close(boolean fromShutdownHook) {
         DbException b = backgroundException.getAndSet(null);
         try {
             closeImpl(fromShutdownHook);

diff --git a/h2/src/main/org/h2/engine/DbSettings.java b/h2/src/main/org/h2/engine/DbSettings.java
@@ -88,13 +88,6 @@ public class DbSettings extends SettingsBase {
      */
     public final boolean caseInsensitiveIdentifiers = get("CASE_INSENSITIVE_IDENTIFIERS", false);
 
-    /**
-     * Database setting <code>DB_CLOSE_ON_EXIT</code> (default: true).
-     * Close the database when the virtual machine exits normally, using a
-     * shutdown hook.
-     */
-    public final boolean dbCloseOnExit = get("DB_CLOSE_ON_EXIT", true);
-
     /**
      * Database setting <code>DEFAULT_CONNECTION</code> (default: false).
      * Whether Java functions can use

diff --git a/h2/src/main/org/h2/engine/DelayedDatabaseCloser.java b/h2/src/main/org/h2/engine/DelayedDatabaseCloser.java
@@ -56,7 +56,7 @@ public void run() {
         WeakReference<Database> ref = databaseRef;
         if (ref != null && (database = ref.get()) != null) {
             try {
-                database.close(false);
+                database.close();
             } catch (RuntimeException e) {
                 // this can happen when stopping a web application,
                 // if loading classes is no longer allowed

diff --git a/h2/src/main/org/h2/engine/OnExitDatabaseCloser.java b/h2/src/main/org/h2/engine/OnExitDatabaseCloser.java
@@ -82,7 +82,7 @@ private static void onShutdown() {
         RuntimeException root = null;
         for (Database database : DATABASES.keySet()) {
             try {
-                database.close(true);
+                database.onShutdown();
             } catch (RuntimeException e) {
                 // this can happen when stopping a web application,
                 // if loading classes is no longer allowed

diff --git a/h2/src/tools/org/h2/build/doc/dictionary.txt b/h2/src/tools/org/h2/build/doc/dictionary.txt
@@ -854,4 +854,4 @@ allotted mismatched wise terminator guarding revolves notion piece submission re
 duplicating unnested hardening sticky massacred
 bck clo cur hwm materializedview udca vol connectionpooldatasource xadatasource
 ampm sssssff sstzh tzs yyyysssss newsequentialid solidus openjdk furthermore ssff secons nashorn fractions
-btrim underscores ffl decomposed decomposition subfield infinities retryable salted
+btrim underscores ffl decomposed decomposition subfield infinities retryable salted establish