Implement downloading of file references, not functional yet

8 files changed, 498 insertions, 109 deletions

diff --git a/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/ConfigProxyRpcServer.java b/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/ConfigProxyRpcServer.java
index 1fced0b1e3d..e877d7f1d0c 100644
--- a/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/ConfigProxyRpcServer.java
+++ b/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/ConfigProxyRpcServer.java
@@ -11,8 +11,12 @@ import com.yahoo.vespa.config.protocol.JRTServerConfigRequest;
 import com.yahoo.vespa.config.protocol.JRTServerConfigRequestV3;
 
 import java.io.File;
-import java.lang.*;
-import java.util.*;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -109,12 +113,12 @@ public class ConfigProxyRpcServer implements Runnable, TargetWatcher, RpcServer
         // Legacy method, needs to be the same name as used in filedistributor
         supervisor.addMethod(new Method("waitFor", "s", "s",
                 this, "getFile")
-                .methodDesc("wait for file reference")
+                .methodDesc("get path to file reference")
                 .paramDesc(0, "file reference", "file reference")
                 .returnDesc(0, "path", "path to file"));
         supervisor.addMethod(new Method("filedistribution.getFile", "s", "s",
                 this, "getFile")
-                .methodDesc("wait for file reference")
+                .methodDesc("get path to file reference")
                 .paramDesc(0, "file reference", "file reference")
                 .returnDesc(0, "path", "path to file"));
         supervisor.addMethod(new Method("filedistribution.getActiveFileReferencesStatus", "", "SD",
@@ -127,6 +131,13 @@ public class ConfigProxyRpcServer implements Runnable, TargetWatcher, RpcServer
                 .methodDesc("set which file references to download")
                 .paramDesc(0, "file references", "file reference to download")
                 .returnDesc(0, "ret", "0 if success, 1 otherwise"));
+        supervisor.addMethod(new Method("filedistribution.receiveFile", "slx", "i", // TODO Temporary method to get started with testing
+                this, "receiveFile")
+                .methodDesc("receive file reference content")
+                .paramDesc(0, "file references", "file reference to download")
+                .paramDesc(1, "filename", "filename")
+                .paramDesc(2, "content", "array of bytes")
+                .returnDesc(0, "ret", "0 if success, 1 otherwise"));
     }
 
     //---------------- RPC methods ------------------------------------
@@ -235,17 +246,33 @@ public class ConfigProxyRpcServer implements Runnable, TargetWatcher, RpcServer
         req.returnValues().add(new StringValue(memoryCache.dumpCacheToDisk(req.parameters().get(0).asString(), memoryCache)));
     }
 
+    // TODO: Duplicate of code in FileAcquirereImpl. Find out where to put it. What about C++ code using this RPC call?
+    private static final int baseErrorCode = 0x10000;
+    private static final int baseFileProviderErrorCode = baseErrorCode + 0x1000;
+
+    private static final int fileReferenceDoesNotExists = baseFileProviderErrorCode;
+    private static final int fileReferenceRemoved = fileReferenceDoesNotExists + 1;
+    private static final int fileReferenceInternalError = fileReferenceRemoved + 1;
+
     @SuppressWarnings({"UnusedDeclaration"})
     public final void getFile(Request req) {
-        // TODO: Detach to avoid holding transport thread
+        req.detach();
         FileReference fileReference = new FileReference(req.parameters().get(0).asString());
-        String pathToFile = proxyServer.fileDownloader()
-                .getFile(fileReference)
-                .orElseGet(() -> new File(""))
-                .getAbsolutePath();
-
-        log.log(LogLevel.INFO, "File reference '" + fileReference.value() + "' available at " + pathToFile);
-        req.returnValues().add(new StringValue(pathToFile));
+        log.log(LogLevel.DEBUG, "getFile() called for file reference '" + fileReference.value() + "'");
+        Optional<File> pathToFile = proxyServer.fileDownloader().getFile(fileReference);
+        try {
+            if (pathToFile.isPresent()) {
+                req.returnValues().add(new StringValue(pathToFile.get().getAbsolutePath()));
+                log.log(LogLevel.INFO, "File reference '" + fileReference.value() + "' available at " + pathToFile.get());
+            } else {
+                log.log(LogLevel.INFO, "File reference '" + fileReference.value() + "' not found, returning error");
+                req.setError(fileReferenceDoesNotExists, "File reference '" + fileReference.value() + "' not found");
+            }
+        } catch (Throwable e) {
+            log.log(LogLevel.WARNING, "File reference '" + fileReference.value() + "' got exeption: " + e.getMessage());
+            req.setError(fileReferenceInternalError, "File reference '" + fileReference.value() + "' removed");
+        }
+        req.returnRequest();
     }
 
     @SuppressWarnings({"UnusedDeclaration"})
@@ -274,11 +301,20 @@ public class ConfigProxyRpcServer implements Runnable, TargetWatcher, RpcServer
         List<FileReference> fileReferences = Stream.of(fileReferenceStrings)
                 .map(FileReference::new)
                 .collect(Collectors.toList());
-        proxyServer.fileDownloader().queueForDownload(fileReferences);
+        proxyServer.fileDownloader().download(fileReferences);
 
         req.returnValues().add(new Int32Value(0));
     }
 
+    @SuppressWarnings({"UnusedDeclaration"})
+    public final void receiveFile(Request req) {
+        FileReference fileReference = new FileReference(req.parameters().get(0).asString());
+        String filename = req.parameters().get(1).asString();
+        byte[] content = req.parameters().get(2).asData();
+        proxyServer.fileDownloader().receiveFile(fileReference, filename, content);
+        req.returnValues().add(new Int32Value(0));
+    }
+
     //----------------------------------------------------
 
     private boolean isProtocolVersionSupported(JRTServerConfigRequest request) {
diff --git a/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/ProxyServer.java b/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/ProxyServer.java
index 4ee77beb2d7..5668852311f 100644
--- a/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/ProxyServer.java
+++ b/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/ProxyServer.java
@@ -83,7 +83,7 @@ public class ProxyServer implements Runnable {
         this.rpcServer = createRpcServer(spec);
         clientUpdater = new ClientUpdater(rpcServer, statistics, delayedResponses);
         this.configClient = createClient(clientUpdater, delayedResponses, source, timingValues, memoryCache, configClient);
-        this.fileDownloader = new FileDownloader(source);
+        this.fileDownloader = new FileDownloader(new JRTConnectionPool(source));
     }
 
     static ProxyServer createTestServer(ConfigSourceSet source) {
diff --git a/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/filedistribution/FileDownloader.java b/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/filedistribution/FileDownloader.java
index 9074527e4e4..21e9b7f160b 100644
--- a/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/filedistribution/FileDownloader.java
+++ b/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/filedistribution/FileDownloader.java
@@ -2,97 +2,147 @@
 package com.yahoo.vespa.config.proxy.filedistribution;
 
 import com.google.common.collect.ImmutableSet;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.SettableFuture;
 import com.yahoo.config.FileReference;
-import com.yahoo.config.subscription.ConfigSourceSet;
 import com.yahoo.log.LogLevel;
+import com.yahoo.vespa.config.ConnectionPool;
 import com.yahoo.vespa.defaults.Defaults;
+import com.yahoo.yolean.Exceptions;
 
 import java.io.File;
 import java.time.Duration;
-import java.time.Instant;
-import java.util.*;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import java.util.logging.Logger;
 
 /**
- * Keeps track of files to download and download status
+ * Handles downloads of files (file references only for now)
  *
  * @author hmusum
  */
 public class FileDownloader {
-    private final static Logger log = Logger.getLogger(FileDownloader.class.getName());
 
+    private final static Logger log = Logger.getLogger(FileDownloader.class.getName());
 
-    private final String filesDirectory;
-    private final ConfigSourceSet configSourceSet;
+    private final File downloadDirectory;
     private final Duration timeout;
-    private final Map<FileReference, Double> downloadStatus = new HashMap<>();
-    private final Set<FileReference> queuedForDownload = new LinkedHashSet<>();
 
-    public FileDownloader(ConfigSourceSet configSourceSet) {
-        this(configSourceSet,
-                Defaults.getDefaults().underVespaHome("var/db/vespa/filedistribution"),
+    private final FileReferenceDownloader fileReferenceDownloader;
+    private final ExecutorService service = Executors.newFixedThreadPool(10);
+
+    public FileDownloader(ConnectionPool connectionPool) {
+        this(connectionPool,
+                new File(Defaults.getDefaults().underVespaHome("var/db/vespa/filedistribution")),
                 Duration.ofMinutes(15));
     }
 
-    FileDownloader(ConfigSourceSet configSourceSet, String filesDirectory, Duration timeout) {
-        this.configSourceSet = configSourceSet;
-        this.filesDirectory = filesDirectory;
+    FileDownloader(ConnectionPool connectionPool, File downloadDirectory, Duration timeout) {
+        this.downloadDirectory = downloadDirectory;
         this.timeout = timeout;
+        this.fileReferenceDownloader = new FileReferenceDownloader(downloadDirectory, connectionPool);
     }
 
     public Optional<File> getFile(FileReference fileReference) {
         Objects.requireNonNull(fileReference, "file reference cannot be null");
-        File directory = new File(filesDirectory, fileReference.value()); // directory with one file
-
+        File directory = new File(downloadDirectory, fileReference.value());
         log.log(LogLevel.DEBUG, "Checking if there is a file in '" + directory.getAbsolutePath() + "' ");
-        Instant end = Instant.now().plus(timeout);
-        do {
-            File[] files = directory.listFiles();
-            if (directory.exists() && directory.isDirectory() && files != null && files.length > 0) {
-                if (files.length != 1) {
-                    throw new RuntimeException("More than one file in  '" + fileReference.value() +
-                            "', expected only one, unable to proceed");
-                }
-                File file = files[0];
-                if (!file.exists()) {
-                    throw new RuntimeException("File with reference '" + fileReference.value() +
-                            "' does not exist");
-                } else if (!file.canRead()) {
-                    throw new RuntimeException("File with reference '" + fileReference.value() +
-                            "'exists, but unable to read it");
-                } else {
-                    downloadStatus.put(fileReference, 100.0);
-                    return Optional.of(file);
-                }
-            } else {
-                queueForDownload(fileReference);
-            }
-            try {
-                Thread.sleep(100);
-            } catch (InterruptedException e) {
-                e.printStackTrace();
-            }
-        } while (Instant.now().isBefore(end));
 
-        return Optional.empty();
+        Optional<File> file = getFileFromFileSystem(fileReference, directory);
+        if (file.isPresent()) {
+            return file;
+        } else {
+            log.log(LogLevel.INFO, "File reference '" + fileReference.value() + "' not found in " +
+                    directory.getAbsolutePath() + ", starting download");
+            return download(fileReference, timeout);
+        }
+    }
+
+    public void download(List<FileReference> fileReferences) {
+        fileReferences.forEach(fileReference -> download(fileReference, timeout));
+    }
+
+    public void receiveFile(FileReference fileReference, String filename, byte[] content) {
+        fileReferenceDownloader.receiveFile(fileReference, filename, content);
+    }
+
+    double downloadStatus(FileReference fileReference) {
+        return fileReferenceDownloader.downloadStatus(fileReference.value());
     }
 
     public Map<FileReference, Double> downloadStatus() {
-        return downloadStatus;
+        return fileReferenceDownloader.downloadStatus();
+    }
+
+    File downloadDirectory() {
+        return downloadDirectory;
     }
 
-    public void queueForDownload(List<FileReference> fileReferences) {
-        fileReferences.forEach(this::queueForDownload);
+    private Optional<File> getFileFromFileSystem(FileReference fileReference, File directory) {
+        File[] files = directory.listFiles();
+        if (directory.exists() && directory.isDirectory() && files != null && files.length > 0) {
+            if (files.length != 1) {
+                throw new RuntimeException("More than one file in  '" + fileReference.value() +
+                        "', expected only one, unable to proceed");
+            }
+            File file = files[0];
+            if (!file.exists()) {
+                throw new RuntimeException("File with reference '" + fileReference.value() +
+                        "' does not exist");
+            } else if (!file.canRead()) {
+                throw new RuntimeException("File with reference '" + fileReference.value() +
+                        "'exists, but unable to read it");
+            } else {
+                fileReferenceDownloader.setDownloadStatus(fileReference.value(), 100.0);
+                return Optional.of(file);
+            }
+        }
+        return Optional.empty();
     }
 
-    private void queueForDownload(FileReference fileReference) {
-        log.log(LogLevel.INFO, "Queued '" + fileReference.value() + "' for download ");
-        queuedForDownload.add(fileReference);
-        downloadStatus.put(fileReference, 0.0);
+    private synchronized Optional<File> download(FileReference fileReference, Duration timeout) {
+        if (fileReferenceDownloader.isDownloading(fileReference)) {
+            log.log(LogLevel.INFO, "Already downloading '" + fileReference.value() + "'");
+            ListenableFuture<Optional<File>> future =
+                    fileReferenceDownloader.addDownloadListener(fileReference, () -> getFile(fileReference));
+            try {
+                return future.get();
+            } catch (InterruptedException | ExecutionException e) {
+                throw new RuntimeException("Failed downloading file reference '" + fileReference.value() + "': " +
+                        Exceptions.toMessageString(e));
+            }
+        }
+
+        SettableFuture<Optional<File>> file = SettableFuture.create();
+        service.submit(() -> fileReferenceDownloader.startDownload(fileReference, timeout, file));
+        log.log(LogLevel.INFO, "Started download of '" + fileReference.value() + "' with timeout " + timeout);
+
+        try {
+            Optional<File> fileDownloaded;
+            try {
+                log.log(LogLevel.INFO, "Waiting for '" + fileReference.value() + "' to download");
+                fileDownloaded = file.get(timeout.getSeconds() - 1, TimeUnit.SECONDS);
+                log.log(LogLevel.INFO, "'" + fileReference.value() + "' downloaded");
+            } catch (TimeoutException e) {
+                log.log(LogLevel.WARNING, "Downloading '" + fileReference.value() + "' timed out");
+                return Optional.empty();
+            }
+            return fileDownloaded;
+        } catch (InterruptedException | ExecutionException e) {
+            throw new RuntimeException("Could not download '" + fileReference.value() + "'");
+        }
     }
 
     ImmutableSet<FileReference> queuedForDownload() {
-        return ImmutableSet.copyOf(queuedForDownload);
+        return ImmutableSet.copyOf(fileReferenceDownloader.queuedForDownload().keySet());
     }
 
-}
\ No newline at end of file
+}
diff --git a/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/filedistribution/FileReferenceDownloader.java b/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/filedistribution/FileReferenceDownloader.java
new file mode 100644
index 00000000000..07b2094ef35
--- /dev/null
+++ b/config-proxy/src/main/java/com/yahoo/vespa/config/proxy/filedistribution/FileReferenceDownloader.java
@@ -0,0 +1,151 @@
+//  Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.config.proxy.filedistribution;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListeningExecutorService;
+import com.google.common.util.concurrent.MoreExecutors;
+import com.google.common.util.concurrent.SettableFuture;
+import com.yahoo.config.FileReference;
+import com.yahoo.jrt.Request;
+import com.yahoo.jrt.StringValue;
+import com.yahoo.log.LogLevel;
+import com.yahoo.vespa.config.Connection;
+import com.yahoo.vespa.config.ConnectionPool;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.time.Duration;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.logging.Logger;
+
+/**
+ * Downloads file reference using rpc requests to config server and keeps track of files being downloaded
+ * <p>
+ * Some methods are synchronized to make sure access to queuedForDownload is atomic
+ *
+ * @author hmusum
+ */
+// TODO: Add retries when a config server does not have a file reference
+class FileReferenceDownloader {
+
+    private final static Logger log = Logger.getLogger(FileReferenceDownloader.class.getName());
+    private final static Duration rpcTimeout = Duration.ofSeconds(10);
+
+    private final File downloadDirectory;
+    private final ListeningExecutorService service = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(10));
+    private final ConnectionPool connectionPool;
+    private final Map<FileReference, SettableFuture<Optional<File>>> queuedForDownload = new LinkedHashMap<>();
+    private final Map<FileReference, Double> downloadStatus = new HashMap<>();
+
+    FileReferenceDownloader(File downloadDirectory, ConnectionPool connectionPool) {
+        this.downloadDirectory = downloadDirectory;
+        this.connectionPool = connectionPool;
+    }
+
+    synchronized Optional<File> startDownload(FileReference fileReference,
+                                              Duration timeout,
+                                              SettableFuture<Optional<File>> file)
+            throws ExecutionException, InterruptedException, TimeoutException {
+        queuedForDownload.put(fileReference, file);
+        setDownloadStatus(fileReference.value(), 0.0);
+        if (startDownloadRpc(fileReference))
+            return file.get(timeout.toMillis(), TimeUnit.MILLISECONDS);
+        else {
+            file.setException(new RuntimeException("Failed getting file"));
+            queuedForDownload.remove(fileReference);
+            return Optional.empty();
+        }
+    }
+
+    void receiveFile(FileReference fileReference, String filename, byte[] content) {
+        File fileReferenceDir = new File(downloadDirectory, fileReference.value());
+        try {
+            Files.createDirectories(fileReferenceDir.toPath());
+            File file = new File(fileReferenceDir, filename);
+            log.log(LogLevel.INFO, "Writing data to " + file.getAbsolutePath());
+            Files.write(file.toPath(), content);
+            completedDownloading(fileReference, file);
+        } catch (IOException e) {
+            log.log(LogLevel.ERROR, "Failed writing file: " + e.getMessage());
+            throw new RuntimeException("Failed writing file: ", e);
+        }
+    }
+
+    Map<FileReference, SettableFuture<Optional<File>>> queuedForDownload() {
+        return queuedForDownload;
+    }
+
+    private synchronized void completedDownloading(FileReference fileReference, File file) {
+        queuedForDownload.get(fileReference).set(Optional.of(file));
+        downloadStatus.put(fileReference, 100.0);
+    }
+
+    private boolean startDownloadRpc(FileReference fileReference) throws ExecutionException, InterruptedException {
+        Connection connection = connectionPool.getCurrent();
+        Request request = new Request("filedistribution.serveFile");
+        request.parameters().add(new StringValue(fileReference.value()));
+
+        execute(request, connection);
+        if (validateResponse(request)) {
+            log.log(LogLevel.DEBUG, "Request callback, OK. Req: " + request + "\nSpec: " + connection);
+            if (request.returnValues().get(0).asInt32() == 0)
+                log.log(LogLevel.INFO, "Found file reference '" + fileReference.value() + "' available at " + connection.getAddress());
+            else
+                log.log(LogLevel.INFO, "File reference '" + fileReference.value() + "' not found for " + connection.getAddress());
+            return true;
+        } else {
+            log.log(LogLevel.WARNING, "Request failed. Req: " + request + "\nSpec: " + connection.getAddress());
+            connection.setError(request.errorCode());
+            // TODO: Retry with another config server
+            return false;
+        }
+    }
+
+    synchronized boolean isDownloading(FileReference fileReference) {
+        return queuedForDownload.containsKey(fileReference);
+    }
+
+    synchronized ListenableFuture<Optional<File>> addDownloadListener(FileReference fileReference, Runnable runnable) {
+        SettableFuture<Optional<File>> future = queuedForDownload.get(fileReference);
+        future.addListener(runnable, service);
+        return future;
+    }
+
+    private void execute(Request request, Connection connection) {
+        connection.invokeSync(request, (double) rpcTimeout.getSeconds());
+    }
+
+    private boolean validateResponse(Request request) {
+        if (request.isError()) {
+            return false;
+        } else if (request.returnValues().size() == 0) {
+            return false;
+        } else if (!request.checkReturnTypes("i")) {
+            log.log(LogLevel.WARNING, "Invalid return types for response: " + request.errorMessage());
+            return false;
+        }
+        return true;
+    }
+
+    double downloadStatus(String file) {
+        return downloadStatus.getOrDefault(new FileReference(file), 0.0);
+    }
+
+    void setDownloadStatus(String file, double percentageDownloaded) {
+        downloadStatus.put(new FileReference(file), percentageDownloaded);
+    }
+
+    Map<FileReference, Double> downloadStatus() {
+        return ImmutableMap.copyOf(downloadStatus);
+    }
+}
diff --git a/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/ConfigProxyRpcServerTest.java b/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/ConfigProxyRpcServerTest.java
index c1e9826e29f..f9b334a6f87 100644
--- a/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/ConfigProxyRpcServerTest.java
+++ b/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/ConfigProxyRpcServerTest.java
@@ -38,8 +38,7 @@ public class ConfigProxyRpcServerTest {
 
     @Test
     public void basic() {
-        ConfigSourceSet configSources = new ConfigSourceSet();
-        ProxyServer proxy = ProxyServer.createTestServer(configSources);
+        ProxyServer proxy = ProxyServer.createTestServer(new MockConfigSource(new MockClientUpdater()));
         Spec spec = new Spec("localhost", 12345);
         ConfigProxyRpcServer server = new ConfigProxyRpcServer(proxy, spec);
         assertThat(server.getSpec(), is(spec));
diff --git a/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/MockConfigSource.java b/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/MockConfigSource.java
index dc9a3408510..2b26996fbdc 100644
--- a/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/MockConfigSource.java
+++ b/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/MockConfigSource.java
@@ -1,12 +1,14 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.config.proxy;
 
-import com.yahoo.config.subscription.ConfigSource;
 import com.yahoo.config.subscription.ConfigSourceSet;
 import com.yahoo.vespa.config.ConfigKey;
 import com.yahoo.vespa.config.RawConfig;
 
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.Set;
 
 /**
  * A simple class to be able to test config proxy without having an RPC config
@@ -37,4 +39,9 @@ class MockConfigSource extends ConfigSourceSet {
         backing.clear();
     }
 
+    @Override
+    public Set<String> getSources() {
+        return Collections.singleton("tcp/localhost:19070,tcp/localhost:19071,tcp/localhost:19072");
+    }
+
 }
diff --git a/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/ProxyServerTest.java b/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/ProxyServerTest.java
index f82d9e90184..3cd0f1043cc 100644
--- a/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/ProxyServerTest.java
+++ b/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/ProxyServerTest.java
@@ -95,7 +95,6 @@ public class ProxyServerTest {
      */
     @Test
     public void testModeSwitch() {
-        ConfigSourceSet source = new ConfigSourceSet(); // Need to use a ConfigSourceSet to test modes
         ProxyServer proxy = ProxyServer.createTestServer(source);
         assertTrue(proxy.getMode().isDefault());
 
diff --git a/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/filedistribution/FileDownloaderTest.java b/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/filedistribution/FileDownloaderTest.java
index ea880e451b6..64ae1a07aea 100644
--- a/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/filedistribution/FileDownloaderTest.java
+++ b/config-proxy/src/test/java/com/yahoo/vespa/config/proxy/filedistribution/FileDownloaderTest.java
@@ -1,79 +1,226 @@
 package com.yahoo.vespa.config.proxy.filedistribution;
 
 import com.yahoo.config.FileReference;
-import com.yahoo.config.subscription.ConfigSourceSet;
 import com.yahoo.io.IOUtils;
+import com.yahoo.jrt.Int32Value;
+import com.yahoo.jrt.Request;
+import com.yahoo.jrt.RequestWaiter;
+import com.yahoo.text.Utf8;
+import com.yahoo.vespa.config.Connection;
+import com.yahoo.vespa.config.ConnectionPool;
+import org.junit.Before;
 import org.junit.Test;
 
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.time.Duration;
-import java.util.*;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 public class FileDownloaderTest {
-    private static final ConfigSourceSet configSourceSet = new ConfigSourceSet();
+
+    private MockConnection connection;
+    private FileDownloader fileDownloader;
+
+    @Before
+    public void setup() {
+        try {
+            File downloadDir = Files.createTempDirectory("filedistribution").toFile();
+            connection = new MockConnection();
+            fileDownloader = new FileDownloader(connection, downloadDir, Duration.ofMillis(3000));
+        } catch (IOException e) {
+            e.printStackTrace();
+            fail(e.getMessage());
+        }
+    }
 
     @Test
-    public void download() throws IOException {
-        File downloadDir = Files.createTempDirectory("filedistribution").toFile();
-        FileDownloader fileDownloader = new FileDownloader(configSourceSet, downloadDir.getAbsolutePath(), Duration.ofMillis(200));
+    public void getFile() throws IOException {
+        File downloadDir = fileDownloader.downloadDirectory();
 
-        // Write a file to download directory to simulate download going OK
-        String fileReferenceString = "somehash";
-        String fileName = "foo.jar";
-        File fileReferenceFullPath = fileReferenceFullPath(downloadDir, fileReferenceString);
-        FileReference fileReference = writeFileReference(downloadDir, fileReferenceString, fileName);
+        {
+            // fileReference already exists on disk, does not have to be downloaded
 
-        // Check that we get correct path and content when asking for file reference
-        Optional<File> pathToFile = fileDownloader.getFile(fileReference);
-        assertTrue(pathToFile.isPresent());
-        String downloadedFile = new File(fileReferenceFullPath, fileName).getAbsolutePath();
-        assertEquals(new File(fileReferenceFullPath, fileName).getAbsolutePath(), downloadedFile);
-        assertEquals("content", IOUtils.readFile(pathToFile.get()));
+            String fileReferenceString = "foo";
+            String filename = "foo.jar";
+            File fileReferenceFullPath = fileReferenceFullPath(downloadDir, fileReferenceString);
+            FileReference fileReference = new FileReference(fileReferenceString);
+            writeFileReference(downloadDir, fileReferenceString, filename);
 
-        // Verify download status
-        Map<FileReference, Double> downloadStatus = fileDownloader.downloadStatus();
-        assertEquals(1, downloadStatus.size());
-        assertDownloadStatus(Collections.singletonList(fileReference), downloadStatus.entrySet().iterator().next(), 100.0);
+            // Check that we get correct path and content when asking for file reference
+            Optional<File> pathToFile = fileDownloader.getFile(fileReference);
+            assertTrue(pathToFile.isPresent());
+            String downloadedFile = new File(fileReferenceFullPath, filename).getAbsolutePath();
+            assertEquals(new File(fileReferenceFullPath, filename).getAbsolutePath(), downloadedFile);
+            assertEquals("content", IOUtils.readFile(pathToFile.get()));
+
+            // Verify download status when downloaded
+            assertDownloadStatus(fileDownloader, fileReference, 100.0);
+        }
+
+        {
+            // fileReference does not exist on disk, needs to be downloaded, but fails when asking upstream for file)
+
+            connection.setResponseHandler(new MockConnection.UnknownFileReferenceResponseHandler());
+
+            FileReference fileReference = new FileReference("bar");
+            File fileReferenceFullPath = fileReferenceFullPath(downloadDir, fileReference.value());
+            assertFalse(fileReferenceFullPath.getAbsolutePath(), fileDownloader.getFile(fileReference).isPresent());
+
+            // Verify download status when unable to download
+            assertDownloadStatus(fileDownloader, fileReference, 0.0);
+        }
+
+        {
+            // fileReference does not exist on disk, needs to be downloaded)
 
-        // Non-existing file
-        assertFalse(fileReferenceFullPath.getAbsolutePath(), fileDownloader.getFile(new FileReference("doesnotexist")).isPresent());
+            FileReference fileReference = new FileReference("fileReference");
+            File fileReferenceFullPath = fileReferenceFullPath(downloadDir, fileReference.value());
+            assertFalse(fileReferenceFullPath.getAbsolutePath(), fileDownloader.getFile(fileReference).isPresent());
+
+            // Verify download status
+            assertDownloadStatus(fileDownloader, fileReference, 0.0);
+
+            // Receives fileReference, should return and make it available to caller
+            String filename = "abc.jar";
+            fileDownloader.receiveFile(fileReference, filename, Utf8.toBytes("some other content"));
+            Optional<File> downloadedFile = fileDownloader.getFile(fileReference);
+
+            assertTrue(downloadedFile.isPresent());
+            File downloadedFileFullPath = new File(fileReferenceFullPath, filename);
+            assertEquals(downloadedFileFullPath.getAbsolutePath(), downloadedFile.get().getAbsolutePath());
+            assertEquals("some other content", IOUtils.readFile(downloadedFile.get()));
+
+            // Verify download status when downloaded
+            assertDownloadStatus(fileDownloader, fileReference, 100.0);
+        }
     }
 
     @Test
     public void setFilesToDownload() throws IOException {
         File downloadDir = Files.createTempDirectory("filedistribution").toFile();
-        FileDownloader fileDownloader = new FileDownloader(configSourceSet, downloadDir.getAbsolutePath(), Duration.ofMillis(200));
-        List<FileReference> fileReferences = Arrays.asList(new FileReference("foo"), new FileReference("bar"));
-        fileDownloader.queueForDownload(fileReferences);
+        MockConnection configSource = new MockConnection();
+        FileDownloader fileDownloader = new FileDownloader(configSource, downloadDir, Duration.ofMillis(200));
+        FileReference foo = new FileReference("foo");
+        FileReference bar = new FileReference("bar");
+        List<FileReference> fileReferences = Arrays.asList(foo, bar);
+        fileDownloader.download(fileReferences);
 
         assertEquals(fileReferences, fileDownloader.queuedForDownload().asList());
 
         // Verify download status
-        Map<FileReference, Double> downloadStatus = fileDownloader.downloadStatus();
-        assertEquals(2, downloadStatus.size());
-
-        assertDownloadStatus(fileReferences, downloadStatus.entrySet().iterator().next(), 0.0);
-        assertDownloadStatus(fileReferences, downloadStatus.entrySet().iterator().next(), 0.0);
+        assertDownloadStatus(fileDownloader, foo, 0.0);
+        assertDownloadStatus(fileDownloader, bar, 0.0);
     }
 
-    private FileReference writeFileReference(File dir, String fileReferenceString, String fileName) throws IOException {
+    private void writeFileReference(File dir, String fileReferenceString, String fileName) throws IOException {
         File file = new File(new File(dir, fileReferenceString), fileName);
         IOUtils.writeFile(file, "content", false);
-        return new FileReference(fileReferenceString);
     }
 
     private File fileReferenceFullPath(File dir, String fileReferenceString) {
         return new File(dir, fileReferenceString);
     }
 
-    private void assertDownloadStatus(List<FileReference> fileReferences, Map.Entry<FileReference, Double> entry, double expectedDownloadStatus) {
-        assertTrue(fileReferences.contains(new FileReference(entry.getKey().value())));
-        assertEquals(expectedDownloadStatus, entry.getValue(), 0.0001);
+    private void assertDownloadStatus(FileDownloader fileDownloader, FileReference fileReference, double expectedDownloadStatus) {
+        double downloadStatus = fileDownloader.downloadStatus(fileReference);
+        assertEquals(expectedDownloadStatus, downloadStatus, 0.0001);
+    }
+
+    private static class MockConnection implements ConnectionPool, com.yahoo.vespa.config.Connection {
+
+        private ResponseHandler responseHandler;
+
+        MockConnection() {
+            this(new FileReferenceFoundResponseHandler());
+        }
+
+        MockConnection(ResponseHandler responseHandler) {
+            this.responseHandler = responseHandler;
+        }
+
+        @Override
+        public void invokeAsync(Request request, double jrtTimeout, RequestWaiter requestWaiter) {
+            responseHandler.request(request);
+        }
+
+        @Override
+        public void invokeSync(Request request, double jrtTimeout) {
+            responseHandler.request(request);
+        }
+
+        @Override
+        public void setError(int errorCode) {
+        }
+
+        @Override
+        public void setSuccess() {
+        }
+
+        @Override
+        public String getAddress() {
+            return null;
+        }
+
+        @Override
+        public void close() {
+        }
+
+        @Override
+        public void setError(Connection connection, int errorCode) {
+            connection.setError(errorCode);
+        }
+
+        @Override
+        public Connection getCurrent() {
+            return this;
+        }
+
+        @Override
+        public Connection setNewCurrentConnection() {
+            return this;
+        }
+
+        @Override
+        public int getSize() {
+            return 1;
+        }
+
+        public void setResponseHandler(ResponseHandler responseHandler) {
+            this.responseHandler = responseHandler;
+        }
+
+        static class FileReferenceFoundResponseHandler implements ResponseHandler {
+
+            @Override
+            public void request(Request request) {
+                if (request.methodName().equals("filedistribution.serveFile"))
+                    request.returnValues().add(new Int32Value(0));
+            }
+        }
+
+        static class UnknownFileReferenceResponseHandler implements ResponseHandler {
+
+            @Override
+            public void request(Request request) {
+                if (request.methodName().equals("filedistribution.serveFile"))
+                    request.returnValues().add(new Int32Value(1));
+            }
+        }
+
+        public interface ResponseHandler {
+
+            void request(Request request);
+
+        }
+
     }
+
 }