Move file handling logic to logthread

2 files changed, 322 insertions, 315 deletions

diff --git a/jdisc_http_service/src/main/java/com/yahoo/container/logging/LogFileHandler.java b/jdisc_http_service/src/main/java/com/yahoo/container/logging/LogFileHandler.java
index 7bd719c161f..f85d58524a8 100644
--- a/jdisc_http_service/src/main/java/com/yahoo/container/logging/LogFileHandler.java
+++ b/jdisc_http_service/src/main/java/com/yahoo/container/logging/LogFileHandler.java
@@ -34,78 +34,13 @@ import java.util.zip.GZIPOutputStream;
  * @author Bob Travis
  * @author bjorncs
  */
-class LogFileHandler <LOGTYPE>  {
+class LogFileHandler <LOGTYPE> {
 
-    enum Compression { NONE, GZIP, ZSTD }
+    enum Compression {NONE, GZIP, ZSTD}
 
     private final static Logger logger = Logger.getLogger(LogFileHandler.class.getName());
 
-    private final Compression compression;
-    private final long[] rotationTimes;
-    private final String filePattern;  // default to current directory, ms time stamp
-    private final String symlinkName;
-    private final ArrayBlockingQueue<Operation<LOGTYPE>> logQueue = new ArrayBlockingQueue<>(100000);
-    private final ExecutorService executor = Executors.newCachedThreadPool(ThreadFactoryFactory.getDaemonThreadFactory("logfilehandler.compression"));
-    private final NativeIO nativeIO = new NativeIO();
-    private final LogThread<LOGTYPE> logThread;
-
-    private volatile FileOutputStream currentOutputStream = null;
-    private volatile long nextRotationTime = 0;
-    private volatile String fileName;
-    private volatile long lastDropPosition = 0;
-
-    private final LogWriter<LOGTYPE> logWriter;
-
-    static private class LogThread<LOGTYPE> extends Thread {
-        final LogFileHandler<LOGTYPE> logFileHandler;
-        long lastFlush = 0;
-        LogThread(LogFileHandler<LOGTYPE> logFile) {
-            super("Logger");
-            setDaemon(true);
-            logFileHandler = logFile;
-        }
-        @Override
-        public void run() {
-            try {
-                storeLogRecords();
-            } catch (InterruptedException e) {
-            } catch (Exception e) {
-                com.yahoo.protect.Process.logAndDie("Failed storing log records", e);
-            }
-
-            logFileHandler.internalFlush();
-        }
-
-        private void storeLogRecords() throws InterruptedException {
-            while (!isInterrupted()) {
-                Operation<LOGTYPE> r = logFileHandler.logQueue.poll(100, TimeUnit.MILLISECONDS);
-                if (r!=null) {
-                    if (r.type == Operation.Type.flush) {
-                        logFileHandler.internalFlush();
-                    } else if (r.type == Operation.Type.close) {
-                        logFileHandler.internalClose();
-                    } else if (r.type == Operation.Type.rotate) {
-                        logFileHandler.internalRotateNow();
-                        lastFlush = System.nanoTime();
-                    } else if (r.type == Operation.Type.log) {
-                        logFileHandler.internalPublish(r.log.get());
-                        flushIfOld(3, TimeUnit.SECONDS);
-                    }
-                    r.countDownLatch.countDown();
-                } else {
-                    flushIfOld(100, TimeUnit.MILLISECONDS);
-                }
-            }
-        }
-
-        private void flushIfOld(long age, TimeUnit unit) {
-            long now = System.nanoTime();
-            if (TimeUnit.NANOSECONDS.toMillis(now - lastFlush) > unit.toMillis(age)) {
-                logFileHandler.internalFlush();
-                lastFlush = now;
-            }
-        }
-    }
+    final LogThread<LOGTYPE> logThread;
 
     LogFileHandler(Compression compression, String filePattern, String rotationTimes, String symlinkName, LogWriter<LOGTYPE> logWriter) {
         this(compression, filePattern, calcTimesMinutes(rotationTimes), symlinkName, logWriter);
@@ -115,16 +50,13 @@ class LogFileHandler <LOGTYPE>  {
             Compression compression,
             String filePattern,
             long[] rotationTimes,
-            String symlinkName, LogWriter<LOGTYPE> logWriter) {
-        this.compression = compression;
-        this.filePattern = filePattern;
-        this.rotationTimes = rotationTimes;
-        this.symlinkName = (symlinkName != null && !symlinkName.isBlank()) ? symlinkName : null;
-        this.logWriter = logWriter;
-        this.logThread = new LogThread<>(this);
+            String symlinkName,
+            LogWriter<LOGTYPE> logWriter) {
+        this.logThread = new LogThread<>(logWriter, filePattern, compression, rotationTimes, symlinkName);
         this.logThread.start();
     }
 
+
     /**
      * Sends logrecord to file, first rotating file if needed.
      *
@@ -138,232 +70,48 @@ class LogFileHandler <LOGTYPE>  {
         addOperationAndWait(new Operation<>(Operation.Type.flush));
     }
 
-    private synchronized void internalFlush() {
-        try {
-            FileOutputStream currentOut = this.currentOutputStream;
-            if (currentOut != null) {
-                if (compression == Compression.GZIP) {
-                    long newPos = currentOut.getChannel().position();
-                    if (newPos > lastDropPosition + 102400) {
-                        nativeIO.dropPartialFileFromCache(currentOut.getFD(), lastDropPosition, newPos, true);
-                        lastDropPosition = newPos;
-                    }
-                } else {
-                    currentOut.flush();
-                }
-            }
-        } catch (IOException e) {
-            logger.warning("Failed dropping from cache : " + Exceptions.toMessageString(e));
-        }
+    /**
+     * Force file rotation now, independent of schedule.
+     */
+    void rotateNow() {
+        addOperationAndWait(new Operation<>(Operation.Type.rotate));
     }
 
     public void close() {
         addOperationAndWait(new Operation<>(Operation.Type.close));
     }
 
-    public void internalClose() {
-        try {
-            internalFlush();
-            FileOutputStream currentOut = this.currentOutputStream;
-            if (currentOut != null) currentOut.close();
-        } catch (Exception e) {
-            logger.log(Level.WARNING, "Got error while closing log file", e);
-        }
-    }
-
-    private void internalPublish(LOGTYPE r) {
-        // first check to see if new file needed.
-        // if so, use this.internalRotateNow() to do it
-
-        long now = System.currentTimeMillis();
-        if (nextRotationTime <= 0) {
-            nextRotationTime = getNextRotationTime(now); // lazy initialization
-        }
-        if (now > nextRotationTime || currentOutputStream == null) {
-            internalRotateNow();
-        }
-        try {
-            FileOutputStream out = this.currentOutputStream;
-            logWriter.write(r, out);
-            out.write('\n');
-        } catch (IOException e) {
-            logger.warning("Failed writing log record: " + Exceptions.toMessageString(e));
-        }
-    }
-
     private void addOperation(Operation<LOGTYPE> op) {
         try {
-            logQueue.put(op);
+            logThread.logQueue.put(op);
         } catch (InterruptedException e) {
         }
     }
+
     private void addOperationAndWait(Operation<LOGTYPE> op) {
         try {
-            logQueue.put(op);
+            logThread.logQueue.put(op);
             op.countDownLatch.await();
         } catch (InterruptedException e) {
         }
     }
 
     /**
-     * Find next rotation after specified time.
-     *
-     * @param now the specified time; if zero, current time is used.
-     * @return the next rotation time
-     */
-    long getNextRotationTime (long now) {
-        if (now <= 0) {
-            now = System.currentTimeMillis();
-        }
-        long nowTod = timeOfDayMillis(now);
-        long next = 0;
-        for (long rotationTime : rotationTimes) {
-            if (nowTod < rotationTime) {
-                next = rotationTime-nowTod + now;
-                break;
-            }
-        }
-        if (next == 0) { // didn't find one -- use 1st time 'tomorrow'
-            next = rotationTimes[0]+lengthOfDayMillis-nowTod + now;
-        }
-
-        return next;
-    }
-
-    private void checkAndCreateDir(String pathname) {
-      int lastSlash = pathname.lastIndexOf("/");
-      if (lastSlash > -1) {
-          String pathExcludingFilename = pathname.substring(0, lastSlash);
-          File filepath = new File(pathExcludingFilename);
-          if (!filepath.exists()) {
-            filepath.mkdirs();
-          }
-      }
-    }
-
-    /**
-     * Force file rotation now, independent of schedule.
+     * Flushes all queued messages, interrupts the log thread in this and
+     * waits for it to end before returning
      */
-    void rotateNow () {
-        addOperationAndWait(new Operation<>(Operation.Type.rotate));
-    }
-
-    // Throw InterruptedException upwards rather than relying on isInterrupted to stop the thread as
-    // isInterrupted() returns false after interruption in p.waitFor
-    private void internalRotateNow() {
-        // figure out new file name, then
-        // use super.setOutputStream to switch to a new file
-
-        String oldFileName = fileName;
-        long now = System.currentTimeMillis();
-        fileName = LogFormatter.insertDate(filePattern, now);
-        internalFlush();
-
-        try {
-            checkAndCreateDir(fileName);
-            FileOutputStream os = new FileOutputStream(fileName, true); // append mode, for safety
-            currentOutputStream = os;
-            lastDropPosition = 0;
-            LogFileDb.nowLoggingTo(fileName);
-        }
-        catch (IOException e) {
-            throw new RuntimeException("Couldn't open log file '" + fileName + "'", e);
-        }
-
-        createSymlinkToCurrentFile();
-
-        nextRotationTime = 0; //figure it out later (lazy evaluation)
-        if ((oldFileName != null)) {
-            File oldFile = new File(oldFileName);
-            if (oldFile.exists()) {
-                if (compression != Compression.NONE) {
-                    executor.execute(() -> runCompression(oldFile, compression));
-                } else {
-                    nativeIO.dropFileFromCache(oldFile);
-                }
-            }
-        }
-    }
-
-
-    private static void runCompression(File oldFile, Compression compression) {
-        switch (compression) {
-            case ZSTD:
-                runCompressionZstd(oldFile.toPath());
-                break;
-            case GZIP:
-                runCompressionGzip(oldFile);
-                break;
-            default:
-                throw new IllegalArgumentException("Unknown compression " + compression);
-        }
-    }
-
-    private static void runCompressionZstd(Path oldFile) {
-        try {
-            Path compressedFile = Paths.get(oldFile.toString() + ".zst");
-            Files.createFile(compressedFile);
-            int bufferSize = 0x400000; // 4M
-            byte[] buffer = new byte[bufferSize];
-            try (ZstdOuputStream out = new ZstdOuputStream(Files.newOutputStream(compressedFile), bufferSize);
-                 InputStream in = Files.newInputStream(oldFile)) {
-                int read;
-                while ((read = in.read(buffer)) >= 0) {
-                    out.write(buffer, 0, read);
-                }
-                out.flush();
-            }
-            Files.delete(oldFile);
-        } catch (IOException e) {
-            logger.log(Level.WARNING, "Failed to compress log file with zstd: " + oldFile, e);
-        }
-    }
-
-    private static void runCompressionGzip(File oldFile) {
-        File gzippedFile = new File(oldFile.getPath() + ".gz");
-        try (GZIPOutputStream compressor = new GZIPOutputStream(new FileOutputStream(gzippedFile), 0x100000);
-             FileInputStream inputStream = new FileInputStream(oldFile))
-        {
-            byte [] buffer = new byte[0x400000]; // 4M buffer
-
-            long totalBytesRead = 0;
-            NativeIO nativeIO = new NativeIO();
-            for (int read = inputStream.read(buffer); read > 0; read = inputStream.read(buffer)) {
-                compressor.write(buffer, 0, read);
-                nativeIO.dropPartialFileFromCache(inputStream.getFD(), totalBytesRead, read, false);
-                totalBytesRead += read;
-            }
-            compressor.finish();
-            compressor.flush();
-
-            oldFile.delete();
-            nativeIO.dropFileFromCache(gzippedFile);
-        } catch (IOException e) {
-            logger.warning("Got '" + e + "' while compressing '" + oldFile.getPath() + "'.");
-        }
-    }
-
-    /** Name files by date - create a symlink with a constant name to the newest file */
-    private void createSymlinkToCurrentFile() {
-        if (symlinkName == null) return;
-        File f = new File(fileName);
-        File f2 = new File(f.getParent(), symlinkName);
-        String [] cmd = new String[]{"/bin/ln", "-sf", f.getName(), f2.getPath()};
+    void shutdown() {
+        logThread.interrupt();
         try {
-            int retval = new ProcessExecuter().exec(cmd).getFirst();
-            // Detonator pattern: Think of all the fun we can have if ln isn't what we
-            // think it is, if it doesn't return, etc, etc
-            if (retval != 0) {
-                logger.warning("Command '" + Arrays.toString(cmd) + "' + failed with exitcode=" + retval);
-            }
-        } catch (IOException e) {
-            logger.warning("Got '" + e + "' while doing'" + Arrays.toString(cmd) + "'.");
+            logThread.join();
+            logThread.executor.shutdown();
+            logThread.executor.awaitTermination(600, TimeUnit.SECONDS);
+        } catch (InterruptedException e) {
         }
     }
 
     /**
      * Calculate rotation times array, given times in minutes, as "0 60 ..."
-     *
      */
     private static long[] calcTimesMinutes(String times) {
         ArrayList<Long> list = new ArrayList<>(50);
@@ -371,33 +119,36 @@ class LogFileHandler <LOGTYPE>  {
         boolean etc = false;
 
         while (i < times.length()) {
-            if (times.charAt(i) == ' ') { i++; continue; } // skip spaces
+            if (times.charAt(i) == ' ') {
+                i++;
+                continue;
+            } // skip spaces
             int j = i; // start of string
             i = times.indexOf(' ', i);
             if (i == -1) i = times.length();
-            if (times.charAt(j) == '.' && times.substring(j,i).equals("...")) { // ...
+            if (times.charAt(j) == '.' && times.substring(j, i).equals("...")) { // ...
                 etc = true;
                 break;
             }
-            list.add(Long.valueOf(times.substring(j,i)));
+            list.add(Long.valueOf(times.substring(j, i)));
         }
 
         int size = list.size();
         long[] longtimes = new long[size];
-        for (i = 0; i<size; i++) {
+        for (i = 0; i < size; i++) {
             longtimes[i] = list.get(i)   // pick up value in minutes past midnight
                            * 60000;                          // and multiply to get millis
         }
 
         if (etc) { // fill out rest of day, same as final interval
-            long endOfDay = 24*60*60*1000;
-            long lasttime = longtimes[size-1];
-            long interval = lasttime - longtimes[size-2];
-            long moreneeded = (endOfDay - lasttime)/interval;
+            long endOfDay = 24 * 60 * 60 * 1000;
+            long lasttime = longtimes[size - 1];
+            long interval = lasttime - longtimes[size - 2];
+            long moreneeded = (endOfDay - lasttime) / interval;
             if (moreneeded > 0) {
-                int newsize = size + (int)moreneeded;
+                int newsize = size + (int) moreneeded;
                 long[] temp = new long[newsize];
-                for (i=0; i<size; i++) {
+                for (i = 0; i < size; i++) {
                     temp[i] = longtimes[i];
                 }
                 while (size < newsize) {
@@ -411,37 +162,296 @@ class LogFileHandler <LOGTYPE>  {
         return longtimes;
     }
 
-    // Support staff :-)
-    private static final long lengthOfDayMillis = 24*60*60*1000;  // ? is this close enough ?
-
-    private static long timeOfDayMillis ( long time ) {
-        return time % lengthOfDayMillis;
+    /**
+     * Only for unit testing. Do not use.
+     */
+    String getFileName() {
+        return logThread.fileName;
     }
 
     /**
-     * Flushes all queued messages, interrupts the log thread in this and
-     * waits for it to end before returning
+     * Handle logging and file operations
      */
-    void shutdown() {
-        logThread.interrupt();
-        try {
-            logThread.join();
-            executor.shutdown();
-            executor.awaitTermination(600, TimeUnit.SECONDS);
+    static class LogThread<LOGTYPE> extends Thread {
+        long lastFlush = 0;
+        private FileOutputStream currentOutputStream = null;
+        private long nextRotationTime = 0;
+        private final String filePattern;  // default to current directory, ms time stamp
+        private String fileName;
+        private long lastDropPosition = 0;
+        private final LogWriter<LOGTYPE> logWriter;
+        private final ArrayBlockingQueue<Operation<LOGTYPE>> logQueue = new ArrayBlockingQueue<>(100000);
+        private final Compression compression;
+        private final long[] rotationTimes;
+        private final String symlinkName;
+        private final ExecutorService executor = Executors.newCachedThreadPool(ThreadFactoryFactory.getDaemonThreadFactory("logfilehandler.compression"));
+        private final NativeIO nativeIO = new NativeIO();
+
+
+        LogThread(LogWriter<LOGTYPE> logWriter, String filePattern, Compression compression, long[] rotationTimes, String symlinkName) {
+            super("Logger");
+            setDaemon(true);
+            this.logWriter = logWriter;
+            this.filePattern = filePattern;
+            this.compression = compression;
+            this.rotationTimes = rotationTimes;
+            this.symlinkName = (symlinkName != null && !symlinkName.isBlank()) ? symlinkName : null;
         }
-        catch (InterruptedException e) {
+
+        @Override
+        public void run() {
+            try {
+                storeLogRecords();
+            } catch (InterruptedException e) {
+            } catch (Exception e) {
+                com.yahoo.protect.Process.logAndDie("Failed storing log records", e);
+            }
+
+            internalFlush();
+        }
+
+        private void storeLogRecords() throws InterruptedException {
+            while (!isInterrupted()) {
+                Operation<LOGTYPE> r = logQueue.poll(100, TimeUnit.MILLISECONDS);
+                if (r != null) {
+                    if (r.type == Operation.Type.flush) {
+                        internalFlush();
+                    } else if (r.type == Operation.Type.close) {
+                        internalClose();
+                    } else if (r.type == Operation.Type.rotate) {
+                        internalRotateNow();
+                        lastFlush = System.nanoTime();
+                    } else if (r.type == Operation.Type.log) {
+                        internalPublish(r.log.get());
+                        flushIfOld(3, TimeUnit.SECONDS);
+                    }
+                    r.countDownLatch.countDown();
+                } else {
+                    flushIfOld(100, TimeUnit.MILLISECONDS);
+                }
+            }
+        }
+
+        private void flushIfOld(long age, TimeUnit unit) {
+            long now = System.nanoTime();
+            if (TimeUnit.NANOSECONDS.toMillis(now - lastFlush) > unit.toMillis(age)) {
+                internalFlush();
+                lastFlush = now;
+            }
+        }
+
+        private synchronized void internalFlush() {
+            try {
+                FileOutputStream currentOut = this.currentOutputStream;
+                if (currentOut != null) {
+                    if (compression == Compression.GZIP) {
+                        long newPos = currentOut.getChannel().position();
+                        if (newPos > lastDropPosition + 102400) {
+                            nativeIO.dropPartialFileFromCache(currentOut.getFD(), lastDropPosition, newPos, true);
+                            lastDropPosition = newPos;
+                        }
+                    } else {
+                        currentOut.flush();
+                    }
+                }
+            } catch (IOException e) {
+                logger.warning("Failed dropping from cache : " + Exceptions.toMessageString(e));
+            }
+        }
+
+        private void internalClose() {
+            try {
+                internalFlush();
+                FileOutputStream currentOut = this.currentOutputStream;
+                if (currentOut != null) currentOut.close();
+            } catch (Exception e) {
+                logger.log(Level.WARNING, "Got error while closing log file", e);
+            }
+        }
+
+        private void internalPublish(LOGTYPE r) {
+            // first check to see if new file needed.
+            // if so, use this.internalRotateNow() to do it
+
+            long now = System.currentTimeMillis();
+            if (nextRotationTime <= 0) {
+                nextRotationTime = getNextRotationTime(now); // lazy initialization
+            }
+            if (now > nextRotationTime || currentOutputStream == null) {
+                internalRotateNow();
+            }
+            try {
+                FileOutputStream out = this.currentOutputStream;
+                logWriter.write(r, out);
+                out.write('\n');
+            } catch (IOException e) {
+                logger.warning("Failed writing log record: " + Exceptions.toMessageString(e));
+            }
+        }
+
+        /**
+         * Find next rotation after specified time.
+         *
+         * @param now the specified time; if zero, current time is used.
+         * @return the next rotation time
+         */
+        long getNextRotationTime(long now) {
+            if (now <= 0) {
+                now = System.currentTimeMillis();
+            }
+            long nowTod = timeOfDayMillis(now);
+            long next = 0;
+            for (long rotationTime : rotationTimes) {
+                if (nowTod < rotationTime) {
+                    next = rotationTime - nowTod + now;
+                    break;
+                }
+            }
+            if (next == 0) { // didn't find one -- use 1st time 'tomorrow'
+                next = rotationTimes[0] + lengthOfDayMillis - nowTod + now;
+            }
+
+            return next;
+        }
+
+        private void checkAndCreateDir(String pathname) {
+            int lastSlash = pathname.lastIndexOf("/");
+            if (lastSlash > -1) {
+                String pathExcludingFilename = pathname.substring(0, lastSlash);
+                File filepath = new File(pathExcludingFilename);
+                if (!filepath.exists()) {
+                    filepath.mkdirs();
+                }
+            }
+        }
+
+
+        // Throw InterruptedException upwards rather than relying on isInterrupted to stop the thread as
+        // isInterrupted() returns false after interruption in p.waitFor
+        private void internalRotateNow() {
+            // figure out new file name, then
+            // use super.setOutputStream to switch to a new file
+
+            String oldFileName = fileName;
+            long now = System.currentTimeMillis();
+            fileName = LogFormatter.insertDate(filePattern, now);
+            internalFlush();
+
+            try {
+                checkAndCreateDir(fileName);
+                FileOutputStream os = new FileOutputStream(fileName, true); // append mode, for safety
+                currentOutputStream = os;
+                lastDropPosition = 0;
+                LogFileDb.nowLoggingTo(fileName);
+            } catch (IOException e) {
+                throw new RuntimeException("Couldn't open log file '" + fileName + "'", e);
+            }
+
+            createSymlinkToCurrentFile();
+
+            nextRotationTime = 0; //figure it out later (lazy evaluation)
+            if ((oldFileName != null)) {
+                File oldFile = new File(oldFileName);
+                if (oldFile.exists()) {
+                    if (compression != Compression.NONE) {
+                        executor.execute(() -> runCompression(oldFile, compression));
+                    } else {
+                        nativeIO.dropFileFromCache(oldFile);
+                    }
+                }
+            }
+        }
+
+
+        private static void runCompression(File oldFile, Compression compression) {
+            switch (compression) {
+                case ZSTD:
+                    runCompressionZstd(oldFile.toPath());
+                    break;
+                case GZIP:
+                    runCompressionGzip(oldFile);
+                    break;
+                default:
+                    throw new IllegalArgumentException("Unknown compression " + compression);
+            }
+        }
+
+        private static void runCompressionZstd(Path oldFile) {
+            try {
+                Path compressedFile = Paths.get(oldFile.toString() + ".zst");
+                Files.createFile(compressedFile);
+                int bufferSize = 0x400000; // 4M
+                byte[] buffer = new byte[bufferSize];
+                try (ZstdOuputStream out = new ZstdOuputStream(Files.newOutputStream(compressedFile), bufferSize);
+                     InputStream in = Files.newInputStream(oldFile)) {
+                    int read;
+                    while ((read = in.read(buffer)) >= 0) {
+                        out.write(buffer, 0, read);
+                    }
+                    out.flush();
+                }
+                Files.delete(oldFile);
+            } catch (IOException e) {
+                logger.log(Level.WARNING, "Failed to compress log file with zstd: " + oldFile, e);
+            }
+        }
+
+        private static void runCompressionGzip(File oldFile) {
+            File gzippedFile = new File(oldFile.getPath() + ".gz");
+            try (GZIPOutputStream compressor = new GZIPOutputStream(new FileOutputStream(gzippedFile), 0x100000);
+                 FileInputStream inputStream = new FileInputStream(oldFile)) {
+                byte[] buffer = new byte[0x400000]; // 4M buffer
+
+                long totalBytesRead = 0;
+                NativeIO nativeIO = new NativeIO();
+                for (int read = inputStream.read(buffer); read > 0; read = inputStream.read(buffer)) {
+                    compressor.write(buffer, 0, read);
+                    nativeIO.dropPartialFileFromCache(inputStream.getFD(), totalBytesRead, read, false);
+                    totalBytesRead += read;
+                }
+                compressor.finish();
+                compressor.flush();
+
+                oldFile.delete();
+                nativeIO.dropFileFromCache(gzippedFile);
+            } catch (IOException e) {
+                logger.warning("Got '" + e + "' while compressing '" + oldFile.getPath() + "'.");
+            }
+        }
+
+        /**
+         * Name files by date - create a symlink with a constant name to the newest file
+         */
+        private void createSymlinkToCurrentFile() {
+            if (symlinkName == null) return;
+            File f = new File(fileName);
+            File f2 = new File(f.getParent(), symlinkName);
+            String[] cmd = new String[]{"/bin/ln", "-sf", f.getName(), f2.getPath()};
+            try {
+                int retval = new ProcessExecuter().exec(cmd).getFirst();
+                // Detonator pattern: Think of all the fun we can have if ln isn't what we
+                // think it is, if it doesn't return, etc, etc
+                if (retval != 0) {
+                    logger.warning("Command '" + Arrays.toString(cmd) + "' + failed with exitcode=" + retval);
+                }
+            } catch (IOException e) {
+                logger.warning("Got '" + e + "' while doing'" + Arrays.toString(cmd) + "'.");
+            }
+        }
+
+        // Support staff :-)
+        private static final long lengthOfDayMillis = 24 * 60 * 60 * 1000;  // ? is this close enough ?
+
+        private static long timeOfDayMillis(long time) {
+            return time % lengthOfDayMillis;
         }
-    }
 
-    /**
-     * Only for unit testing. Do not use.
-     */
-    String getFileName() {
-        return fileName;
     }
 
     private static class Operation<LOGTYPE> {
-        enum Type {log, flush, close, rotate};
+        enum Type {log, flush, close, rotate}
+
+        ;
 
         final Type type;
 
@@ -451,12 +461,15 @@ class LogFileHandler <LOGTYPE>  {
         Operation(Type type) {
             this(type, Optional.empty());
         }
+
         Operation(LOGTYPE log) {
             this(Type.log, Optional.of(log));
         }
+
         private Operation(Type type, Optional<LOGTYPE> log) {
             this.type = type;
             this.log = log;
         }
     }
 }
+
diff --git a/jdisc_http_service/src/test/java/com/yahoo/container/logging/LogFileHandlerTestCase.java b/jdisc_http_service/src/test/java/com/yahoo/container/logging/LogFileHandlerTestCase.java
index 7b46e1540f6..cd3c174a12e 100644
--- a/jdisc_http_service/src/test/java/com/yahoo/container/logging/LogFileHandlerTestCase.java
+++ b/jdisc_http_service/src/test/java/com/yahoo/container/logging/LogFileHandlerTestCase.java
@@ -42,20 +42,14 @@ public class LogFileHandlerTestCase {
 
         String pattern = root.getAbsolutePath() + "/logfilehandlertest.%Y%m%d%H%M%S";
         long[] rTimes = {1000, 2000, 10000};
-        Formatter formatter = new Formatter() {
-            public String format(LogRecord r) {
-                DateFormat df = new SimpleDateFormat("yyyy.MM.dd:HH:mm:ss.SSS");
-                String timeStamp = df.format(new Date(r.getMillis()));
-                return ("["+timeStamp+"]" + " " + formatMessage(r) + "\n");
-            }
-        };
         LogFileHandler<String> h = new LogFileHandler<>(Compression.NONE, pattern, rTimes, null, new StringLogWriter());
         long now = System.currentTimeMillis();
         long millisPerDay = 60*60*24*1000;
         long tomorrowDays = (now / millisPerDay) +1;
         long tomorrowMillis = tomorrowDays * millisPerDay;
-        assertThat(tomorrowMillis+1000).isEqualTo(h.getNextRotationTime(tomorrowMillis));
-        assertThat(tomorrowMillis+10000).isEqualTo(h.getNextRotationTime(tomorrowMillis+3000));
+
+        assertThat(tomorrowMillis+1000).isEqualTo(h.logThread.getNextRotationTime(tomorrowMillis));
+        assertThat(tomorrowMillis+10000).isEqualTo(h.logThread.getNextRotationTime(tomorrowMillis+3000));
         String message = "test";
         h.publish(message);
         h.publish( "another test");