#632 - ENH: Alter AutoTune such that it saves back to autotune.xml (rename any existing autotune file)

src/main/java/com/avaje/ebeaninternal/server/autotune/service/AutoTuneAllCollection.java

@@ -41,10 +41,10 @@ public class AutoTuneAllCollection {
   /**
    * Write the document as an xml file.
    */
-  public void writeFile(String filePrefix) {
+  public void writeFile(String filePrefix, boolean withNow) {
 
     AutoTuneXmlWriter writer = new AutoTuneXmlWriter();
-    writer.write(document, filePrefix);
+    writer.write(document, filePrefix, withNow);
   }
 
   /**

src/main/java/com/avaje/ebeaninternal/server/autotune/service/AutoTuneDiffCollection.java

@@ -76,7 +76,7 @@ public class AutoTuneDiffCollection {
   public void writeFile(String filePrefix) {
 
     AutoTuneXmlWriter writer = new AutoTuneXmlWriter();
-    writer.write(document, filePrefix);
+    writer.write(document, filePrefix, true);
   }
 
   /**

src/main/java/com/avaje/ebeaninternal/server/autotune/service/AutoTuneXmlWriter.java

@@ -15,19 +15,27 @@ import java.util.Date;
  */
 public class AutoTuneXmlWriter {
 
+  /**
+   * Return 'now' as a string to second precision.
+   */
+  public static String now() {
+    SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd-HHmmss");
+    return df.format(new Date());
+  }
+
   /**
    * Write the document as xml file with the given prefix.
    */
-  public void write(Autotune document, String filePrefix) {
+  public void write(Autotune document, String fileName, boolean withNow) {
 
     SortAutoTuneDocument.sort(document);
 
-    SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd-HHmmss");
-    String now = df.format(new Date());
+    if (withNow) {
+      fileName += "-" + now() + ".xml";
+    }
 
     // write the file with serverName and now suffix as we can output the profiling many times
-    File file = new File(filePrefix + "-" + now + ".xml");
-    write(document, file);
+    write(document, new File(fileName));
   }
 
   /**

src/main/java/com/avaje/ebeaninternal/server/autotune/service/DefaultAutoTuneService.java

@@ -185,7 +185,15 @@ public class DefaultAutoTuneService implements AutoTuneService {
     } else {
       AutoTuneAllCollection event = new AutoTuneAllCollection(queryTuner);
       int size = event.size();
-      event.writeFile(profilingFile + "-" + serverName + "-all");
+      File existingTuning = new File(tuningFile);
+      if (existingTuning.exists()) {
+        // rename the existing autotune.xml file (appending 'now')
+        if (!existingTuning.renameTo(new File(tuningFile+"."+AutoTuneXmlWriter.now()))) {
+          logger.warn("Failed to rename autotune file [{}]", tuningFile);
+        }
+      }
+
+      event.writeFile(tuningFile, false);
       logger.info("query tuning detected [{}] changes, writing all [{}] tuning entries for server:{}", runtimeChangeCount, size, serverName);
     }
   }