Merge pull request #8872 from printomi/ui_multisession_arbiter

DL4J UI: Add multi-session support for Arbiter

arbiter/arbiter-ui/src/main/java/org/deeplearning4j/arbiter/ui/module/ArbiterModule.java

@@ -36,6 +36,7 @@ import org.deeplearning4j.arbiter.ui.data.ModelInfoPersistable;
 import org.deeplearning4j.arbiter.ui.misc.UIUtils;
 import org.deeplearning4j.arbiter.util.ObjectUtils;
 import org.deeplearning4j.nn.conf.serde.JsonMappers;
+import org.deeplearning4j.ui.VertxUIServer;
 import org.deeplearning4j.ui.api.Component;
 import org.deeplearning4j.ui.api.*;
 import org.deeplearning4j.ui.components.chart.ChartLine;
@@ -50,6 +51,7 @@ import org.deeplearning4j.ui.components.text.style.StyleText;
 import org.deeplearning4j.ui.i18n.I18NResource;
 import org.joda.time.format.DateTimeFormat;
 import org.joda.time.format.DateTimeFormatter;
+import org.nd4j.common.function.Function;
 import org.nd4j.common.primitives.Pair;
 import org.nd4j.shade.jackson.core.JsonProcessingException;
 
@@ -77,7 +79,6 @@ public class ArbiterModule implements UIModule {
 
     private Map<String, Long> lastUpdateForSession = Collections.synchronizedMap(new HashMap<>());
 
-
     //Styles for UI:
     private static final StyleTable STYLE_TABLE = new StyleTable.Builder()
             .width(100, LengthUnit.Percent)
@@ -134,20 +135,135 @@ public class ArbiterModule implements UIModule {
 
     @Override
     public List<Route> getRoutes() {
-        Route r1 = new Route("/arbiter", HttpMethod.GET, (path, rc) -> rc.response()
+        boolean multiSession = VertxUIServer.getMultiSession().get();
-                .putHeader("content-type", "text/html; charset=utf-8").sendFile("templates/ArbiterUI.html"));
+        List<Route> r = new ArrayList<>();
-        Route r3 = new Route("/arbiter/lastUpdate", HttpMethod.GET, (path, rc) -> this.getLastUpdateTime(rc));
+        r.add(new Route("/arbiter/multisession", HttpMethod.GET,
-        Route r4 = new Route("/arbiter/lastUpdate/:ids", HttpMethod.GET, (path, rc) -> this.getModelLastUpdateTimes(path.get(0), rc));
+                (path, rc) -> rc.response().end(multiSession ? "true" : "false")));
-        Route r5 = new Route("/arbiter/candidateInfo/:id", HttpMethod.GET, (path, rc) -> this.getCandidateInfo(path.get(0), rc));
+        if (multiSession) {
-        Route r6 = new Route("/arbiter/config", HttpMethod.GET, (path, rc) -> this.getOptimizationConfig(rc));
+            r.add(new Route("/arbiter", HttpMethod.GET, (path, rc) -> this.listSessions(rc)));
-        Route r7 = new Route("/arbiter/results", HttpMethod.GET, (path, rc) -> this.getSummaryResults(rc));
+            r.add(new Route("/arbiter/:sessionId", HttpMethod.GET, (path, rc) -> {
-        Route r8 = new Route("/arbiter/summary", HttpMethod.GET, (path, rc) -> this.getSummaryStatus(rc));
+                if (knownSessionIDs.containsKey(path.get(0))) {
+                    rc.response()
+                            .putHeader("content-type", "text/html; charset=utf-8")
+                            .sendFile("templates/ArbiterUI.html");
+                } else {
+                    sessionNotFound(path.get(0), rc.request().path(), rc);
+                }
+            }));
 
-        Route r9a = new Route("/arbiter/sessions/all", HttpMethod.GET, (path, rc) -> this.listSessions(rc));
+            r.add(new Route("/arbiter/:sessionId/lastUpdate", HttpMethod.GET, (path, rc) -> {
-        Route r9b = new Route("/arbiter/sessions/current", HttpMethod.GET, (path, rc) -> this.currentSession(rc));
+                if (knownSessionIDs.containsKey(path.get(0))) {
-        Route r9c = new Route("/arbiter/sessions/set/:to", HttpMethod.GET, (path, rc) -> this.setSession(path.get(0), rc));
+                    this.getLastUpdateTime(path.get(0), rc);
+                } else {
+                    sessionNotFound(path.get(0), rc.request().path(), rc);
+                }
+            }));
+            r.add(new Route("/arbiter/:sessionId/candidateInfo/:id", HttpMethod.GET, (path, rc) -> {
+                if (knownSessionIDs.containsKey(path.get(0))) {
+                    this.getCandidateInfo(path.get(0), path.get(1), rc);
+                } else {
+                    sessionNotFound(path.get(0), rc.request().path(), rc);
+                }
+            }));
+            r.add(new Route("/arbiter/:sessionId/config", HttpMethod.GET, (path, rc) -> {
+                if (knownSessionIDs.containsKey(path.get(0))) {
+                    this.getOptimizationConfig(path.get(0), rc);
+                } else {
+                    sessionNotFound(path.get(0), rc.request().path(), rc);
+                }
+            }));
+            r.add(new Route("/arbiter/:sessionId/results", HttpMethod.GET, (path, rc) -> {
+                if (knownSessionIDs.containsKey(path.get(0))) {
+                    this.getSummaryResults(path.get(0), rc);
+                } else {
+                    sessionNotFound(path.get(0), rc.request().path(), rc);
+                }
+            }));
+            r.add(new Route("/arbiter/:sessionId/summary", HttpMethod.GET, (path, rc) -> {
+                if (knownSessionIDs.containsKey(path.get(0))) {
+                    this.getSummaryStatus(path.get(0), rc);
+                } else {
+                    sessionNotFound(path.get(0), rc.request().path(), rc);
+                }
+            }));
+        } else {
+            r.add(new Route("/arbiter", HttpMethod.GET, (path, rc) -> rc.response()
+                    .putHeader("content-type", "text/html; charset=utf-8")
+                    .sendFile("templates/ArbiterUI.html")));
+            r.add(new Route("/arbiter/lastUpdate", HttpMethod.GET, (path, rc) -> this.getLastUpdateTime(null, rc)));
+            r.add(new Route("/arbiter/candidateInfo/:id", HttpMethod.GET,
+                    (path, rc) -> this.getCandidateInfo(null, path.get(0), rc)));
+            r.add(new Route("/arbiter/config", HttpMethod.GET, (path, rc) -> this.getOptimizationConfig(null, rc)));
+            r.add(new Route("/arbiter/results", HttpMethod.GET, (path, rc) -> this.getSummaryResults(null, rc)));
+            r.add(new Route("/arbiter/summary", HttpMethod.GET, (path, rc) -> this.getSummaryStatus(null, rc)));
 
-        return Arrays.asList(r1, r3, r4, r5, r6, r7, r8, r9a, r9b, r9c);
+            r.add(new Route("/arbiter/sessions/current", HttpMethod.GET, (path, rc) -> this.currentSession(rc)));
+            r.add(new Route("/arbiter/sessions/set/:to", HttpMethod.GET,
+                    (path, rc) -> this.setSession(path.get(0), rc)));
+        }
+        // common for single- and multi-session mode
+        r.add(new Route("/arbiter/sessions/all", HttpMethod.GET, (path, rc) -> this.sessionInfo(rc)));
+
+        return r;
+    }
+
+
+    /**
+     * Load StatsStorage via provider, or return "not found"
+     *
+     * @param sessionId  session ID to look fo with provider
+     * @param targetPath one of overview / model / system, or null
+     * @param rc routing context
+     */
+    private void sessionNotFound(String sessionId, String targetPath, RoutingContext rc) {
+        Function<String, Boolean> loader = VertxUIServer.getInstance().getStatsStorageLoader();
+        if (loader != null && loader.apply(sessionId)) {
+            if (targetPath != null) {
+                rc.reroute(targetPath);
+            } else {
+                rc.response().end();
+            }
+        } else {
+            rc.response().setStatusCode(HttpResponseStatus.NOT_FOUND.code())
+                    .end("Unknown session ID: " + sessionId);
+        }
+    }
+
+
+    /**
+     * List optimization sessions. Returns a HTML list of arbiter sessions
+     */
+    private synchronized void listSessions(RoutingContext rc) {
+        StringBuilder sb = new StringBuilder("<!DOCTYPE html>\n" +
+                "<html lang=\"en\">\n" +
+                "<head>\n" +
+                "        <meta charset=\"utf-8\">\n" +
+                "        <title>Optimization sessions - DL4J Arbiter UI</title>\n" +
+                "    </head>\n" +
+                "\n" +
+                "    <body>\n" +
+                "        <h1>DL4J Arbiter UI</h1>\n" +
+                "        <p>UI server is in multi-session mode." +
+                " To visualize an optimization session, please select one from the following list.</p>\n" +
+                "        <h2>List of attached optimization sessions</h2>\n");
+        if (!knownSessionIDs.isEmpty()) {
+            sb.append("        <ul>");
+            for (String sessionId : knownSessionIDs.keySet()) {
+                sb.append("            <li><a href=\"/arbiter/")
+                        .append(sessionId).append("\">")
+                        .append(sessionId).append("</a></li>\n");
+            }
+            sb.append("        </ul>");
+        } else {
+            sb.append("No optimization session attached.");
+        }
+
+        sb.append("    </body>\n" +
+                "</html>\n");
+
+        rc.response()
+                .putHeader("content-type", "text/html; charset=utf-8")
+                .end(sb.toString());
     }
 
     @Override
@@ -201,7 +317,7 @@ public class ArbiterModule implements UIModule {
                 .end(asJson(sid));
     }
 
-    private void listSessions(RoutingContext rc) {
+    private void sessionInfo(RoutingContext rc) {
         rc.response()
                 .putHeader("content-type", "application/json")
                 .end(asJson(knownSessionIDs.keySet()));
@@ -257,10 +373,25 @@ public class ArbiterModule implements UIModule {
 
     /**
      * Return the last update time for the page
+     * @param sessionId session ID (optional, for multi-session mode)
+     * @param rc routing context
      */
-    private void getLastUpdateTime(RoutingContext rc){
+    private void getLastUpdateTime(String sessionId, RoutingContext rc){
-        //TODO - this forces updates on every request... which is fine, just inefficient
+        if (sessionId == null) {
-        long t = System.currentTimeMillis();
+            sessionId = currentSessionID;
+        }
+        StatsStorage ss = knownSessionIDs.get(sessionId);
+        List<Persistable> latestUpdates = ss.getLatestUpdateAllWorkers(sessionId, ARBITER_UI_TYPE_ID);
+        long t = 0;
+        if (latestUpdates.isEmpty()) {
+            t = System.currentTimeMillis();
+        } else {
+            for (Persistable update : latestUpdates) {
+                if (update.getTimeStamp() > t) {
+                    t = update.getTimeStamp();
+                }
+            }
+        }
         UpdateStatus us = new UpdateStatus(t, t, t);
 
         rc.response().putHeader("content-type", "application/json").end(asJson(us));
@@ -274,56 +405,28 @@ public class ArbiterModule implements UIModule {
         }
     }
 
-    /**
-     * Get the last update time for the specified model IDs
-     * @param modelIDs Model IDs to get the update time for
-     */
-    private void getModelLastUpdateTimes(String modelIDs, RoutingContext rc){
-        if(currentSessionID == null){
-            rc.response().end();
-            return;
-        }
-
-        StatsStorage ss = knownSessionIDs.get(currentSessionID);
-        if(ss == null){
-            log.debug("getModelLastUpdateTimes(): Session ID is unknown: {}", currentSessionID);
-            rc.response().end("-1");
-            return;
-        }
-
-        String[] split = modelIDs.split(",");
-
-        long[] lastUpdateTimes = new long[split.length];
-        for( int i=0; i<split.length; i++ ){
-            String s = split[i];
-            Persistable p = ss.getLatestUpdate(currentSessionID, ARBITER_UI_TYPE_ID, s);
-            if(p != null){
-                lastUpdateTimes[i] = p.getTimeStamp();
-            }
-        }
-
-        rc.response().putHeader("content-type", "application/json").end(asJson(lastUpdateTimes));
-    }
-
     /**
      * Get the info for a specific candidate - last section in the UI
-     *
+     * @param sessionId session ID (optional, for multi-session mode)
      * @param candidateId ID for the candidate
-     * @return Content/info for the candidate
+     * @param rc routing context
      */
-    private void getCandidateInfo(String candidateId, RoutingContext rc){
+    private void getCandidateInfo(String sessionId, String candidateId, RoutingContext rc){
-
+        if (sessionId == null) {
-        StatsStorage ss = knownSessionIDs.get(currentSessionID);
+            sessionId = currentSessionID;
+        }
+        StatsStorage ss = knownSessionIDs.get(sessionId);
         if(ss == null){
-            log.debug("getModelLastUpdateTimes(): Session ID is unknown: {}", currentSessionID);
+            log.debug("getModelLastUpdateTimes(): Session ID is unknown: {}", sessionId);
             rc.response().end();
             return;
         }
 
-        GlobalConfigPersistable gcp = (GlobalConfigPersistable)ss.getStaticInfo(currentSessionID, ARBITER_UI_TYPE_ID, GlobalConfigPersistable.GLOBAL_WORKER_ID);;
+        GlobalConfigPersistable gcp = (GlobalConfigPersistable)ss
+                .getStaticInfo(sessionId, ARBITER_UI_TYPE_ID, GlobalConfigPersistable.GLOBAL_WORKER_ID);
         OptimizationConfiguration oc = gcp.getOptimizationConfiguration();
 
-        Persistable p = ss.getLatestUpdate(currentSessionID, ARBITER_UI_TYPE_ID, candidateId);
+        Persistable p = ss.getLatestUpdate(sessionId, ARBITER_UI_TYPE_ID, candidateId);
         if(p == null){
             String title = "No results found for model " + candidateId + ".";
             ComponentText ct = new ComponentText.Builder(title,STYLE_TEXT_SZ12).build();
@@ -493,17 +596,21 @@ public class ArbiterModule implements UIModule {
 
     /**
      * Get the optimization configuration - second section in the page
+     * @param sessionId session ID (optional, for multi-session mode)
+     * @param rc routing context
      */
-    private void getOptimizationConfig(RoutingContext rc){
+    private void getOptimizationConfig(String sessionId, RoutingContext rc){
-
+        if (sessionId == null) {
-        StatsStorage ss = knownSessionIDs.get(currentSessionID);
+            sessionId = currentSessionID;
+        }
+        StatsStorage ss = knownSessionIDs.get(sessionId);
         if(ss == null){
-            log.debug("getOptimizationConfig(): Session ID is unknown: {}", currentSessionID);
+            log.debug("getOptimizationConfig(): Session ID is unknown: {}", sessionId);
             rc.response().end();
             return;
         }
 
-        Persistable p = ss.getStaticInfo(currentSessionID, ARBITER_UI_TYPE_ID, GlobalConfigPersistable.GLOBAL_WORKER_ID);
+        Persistable p = ss.getStaticInfo(sessionId, ARBITER_UI_TYPE_ID, GlobalConfigPersistable.GLOBAL_WORKER_ID);
 
         if(p == null){
             log.debug("No static info");
@@ -593,15 +700,23 @@ public class ArbiterModule implements UIModule {
         rc.response().putHeader("content-type", "application/json").end(asJson(cd));
     }
 
-    private void getSummaryResults(RoutingContext rc){
+    /**
-        StatsStorage ss = knownSessionIDs.get(currentSessionID);
+     * Get candidates summary results list - third section on the page: Results table
+     * @param sessionId session ID (optional, for multi-session mode)
+     * @param rc routing context
+     */
+    private void getSummaryResults(String sessionId, RoutingContext rc){
+        if (sessionId == null) {
+            sessionId = currentSessionID;
+        }
+        StatsStorage ss = knownSessionIDs.get(sessionId);
         if(ss == null){
-            log.debug("getSummaryResults(): Session ID is unknown: {}", currentSessionID);
+            log.debug("getSummaryResults(): Session ID is unknown: {}", sessionId);
             rc.response().end();
             return;
         }
 
-        List<Persistable> allModelInfoTemp = new ArrayList<>(ss.getLatestUpdateAllWorkers(currentSessionID, ARBITER_UI_TYPE_ID));
+        List<Persistable> allModelInfoTemp = new ArrayList<>(ss.getLatestUpdateAllWorkers(sessionId, ARBITER_UI_TYPE_ID));
         List<String[]> table = new ArrayList<>();
         for(Persistable per : allModelInfoTemp){
             ModelInfoPersistable mip = (ModelInfoPersistable)per;
@@ -614,16 +729,21 @@ public class ArbiterModule implements UIModule {
 
     /**
      * Get summary status information: first section in the page
+     * @param sessionId session ID (optional, for multi-session mode)
+     * @param rc routing context
      */
-    private void getSummaryStatus(RoutingContext rc){
+    private void getSummaryStatus(String sessionId, RoutingContext rc){
-        StatsStorage ss = knownSessionIDs.get(currentSessionID);
+        if (sessionId == null) {
+            sessionId = currentSessionID;
+        }
+        StatsStorage ss = knownSessionIDs.get(sessionId);
         if(ss == null){
-            log.debug("getOptimizationConfig(): Session ID is unknown: {}", currentSessionID);
+            log.debug("getOptimizationConfig(): Session ID is unknown: {}", sessionId);
             rc.response().end();
             return;
         }
 
-        Persistable p = ss.getStaticInfo(currentSessionID, ARBITER_UI_TYPE_ID, GlobalConfigPersistable.GLOBAL_WORKER_ID);
+        Persistable p = ss.getStaticInfo(sessionId, ARBITER_UI_TYPE_ID, GlobalConfigPersistable.GLOBAL_WORKER_ID);
 
         if(p == null){
             log.info("No static info");
@@ -643,7 +763,7 @@ public class ArbiterModule implements UIModule {
 
         //How to get this? query all model infos...
 
-        List<Persistable> allModelInfoTemp = new ArrayList<>(ss.getLatestUpdateAllWorkers(currentSessionID, ARBITER_UI_TYPE_ID));
+        List<Persistable> allModelInfoTemp = new ArrayList<>(ss.getLatestUpdateAllWorkers(sessionId, ARBITER_UI_TYPE_ID));
         List<ModelInfoPersistable> allModelInfo = new ArrayList<>();
         for(Persistable per : allModelInfoTemp){
             ModelInfoPersistable mip = (ModelInfoPersistable)per;
@@ -668,7 +788,6 @@ public class ArbiterModule implements UIModule {
 
         //TODO: I18N
 
-        //TODO don't use currentTimeMillis due to stored data??
         long bestTime;
         Double bestScore = null;
         String bestModelString = null;
@@ -685,7 +804,12 @@ public class ArbiterModule implements UIModule {
         String execTotalRuntimeStr = "";
         if(execStartTime > 0){
             execStartTimeStr = TIME_FORMATTER.print(execStartTime);
-            execTotalRuntimeStr = UIUtils.formatDuration(System.currentTimeMillis() - execStartTime);
+            // allModelInfo is sorted by Persistable::getTimeStamp
+            long lastCompleteTime = execStartTime;
+            if (!allModelInfo.isEmpty()) {
+                lastCompleteTime = allModelInfo.get(allModelInfo.size() - 1).getTimeStamp();
+            }
+            execTotalRuntimeStr = UIUtils.formatDuration(lastCompleteTime - execStartTime);
         }
 
 

arbiter/arbiter-ui/src/main/resources/templates/ArbiterUI.html

@@ -198,27 +198,38 @@
 
     var selectedCandidateIdx = null;
     
-    //Set basic interval function to do updates
+    //Multi-session mode
-    setInterval(doUpdate,5000);    //Loop every 5 seconds
+    var multiSession = null;
+    //Session selection
+    var currSession = "";
     
+    function getSessionIdFromUrl() {
+        // path is like /arbiter/:sessionId/overview
+        var sessionIdRegexp = /\/arbiter\/([^\/]+)/g;
+        var match = sessionIdRegexp.exec(window.location.pathname)
+        return match[1];
+    }
 
-    function doUpdate(){
+    function getCurrSession(callback) {
-        //Get the update status, and do something with it:
+        if (multiSession) {
-        $.get("/arbiter/lastUpdate",function(data){
+            if (currSession == "") {
-            //Encoding: matches names in UpdateStatus class
+                // get only once
-            var jsonObj = JSON.parse(JSON.stringify(data));
+                currSession = getSessionIdFromUrl();
-            var statusTime = jsonObj['statusUpdateTime'];
+            }
-            var settingsTime = jsonObj['settingsUpdateTime'];
+            //we don't show session selector in multi-session mode (one can list sessions at /arbiter)
-            var resultsTime = jsonObj['resultsUpdateTime'];
+            callback();
-            //console.log("Last update times: " + statusTime + ", " + settingsTime + ", " + resultsTime);
+        } else {
-
+            $.ajax({
-            //Update available sessions:
+                url: "/arbiter/sessions/current",
-            var currSession;
+                async: true,
-            $.get("/arbiter/sessions/current", function(data){
+                error: function (query, status, error) {
-                currSession = data; //JSON.stringify(data);
+                    console.log("Error getting data: " + error);
-                console.log("Current: " + currSession);
+                },
-            });
+                success: function (data) {
+                    currSession = data;
+                    console.log("Current session: " + currSession);
                     
+                    //Update available sessions in session selector
                     $.get("/arbiter/sessions/all", function(data){
                         var keys = data;    // JSON.stringify(data);
 
@@ -239,15 +250,56 @@
                             $("#sessionSelect option[value='" + keys[currSelectedIdx] +"']").attr("selected", "selected");
                             $("#sessionSelectDiv").show();
                         }
-//                console.log("Got sessions: " + keys + ", current: " + currSession);
+        //                console.log("Got sessions: " + keys + ", current: " + currSession);
+                        callback();
                     });
                     
+                }
+            });
+        }
+    }
+    
+    function getSessionSettings(callback) {
+        // load only once
+        if (multiSession != null) {
+            getCurrSession(callback);
+        } else {
+            $.ajax({
+                url: "/arbiter/multisession",
+                async: true,
+                error: function (query, status, error) {
+                    console.log("Error getting data: " + error);
+                },
+                success: function (data) {
+                    multiSession = data == "true";
+                    getCurrSession(callback);
+                }
+            });
+        }
+    }
+    
+    //Initial update
+    doUpdate();
+    //Set basic interval function to do updates
+    setInterval(doUpdate,5000);    //Loop every 5 seconds
+    
+    function doUpdate(){
+        //Get the update status, and do something with it:
+        getSessionSettings(function(){
+            var sessionUpdateUrl = multiSession ? "/arbiter/" + currSession + "/lastUpdate" : "/arbiter/lastUpdate";
+            $.get(sessionUpdateUrl,function(data){
+                //Encoding: matches names in UpdateStatus class
+                var jsonObj = JSON.parse(JSON.stringify(data));
+                var statusTime = jsonObj['statusUpdateTime'];
+                var settingsTime = jsonObj['settingsUpdateTime'];
+                var resultsTime = jsonObj['resultsUpdateTime'];
+                //console.log("Last update times: " + statusTime + ", " + settingsTime + ", " + resultsTime);
 
                 //Check last update times for each part of document, and update as necessary
                 //First section: summary status
                 if(lastStatusUpdateTime != statusTime){
-                //Get JSON: address set by SummaryStatusResource
+                    var summaryStatusUrl = multiSession ? "/arbiter/" + currSession + "/summary" : "/arbiter/summary";
-                $.get("/arbiter/summary",function(data){
+                    $.get(summaryStatusUrl,function(data){
                         var summaryStatusDiv = $('#statusdiv');
                         summaryStatusDiv.html('');
 
@@ -262,7 +314,8 @@
                 //Second section: Optimization settings
                 if(lastSettingsUpdateTime != settingsTime){
                     //Get JSON for components
-                $.get("/arbiter/config",function(data){
+                    var settingsUrl = multiSession ? "/arbiter/" + currSession + "/config" : "/arbiter/config";
+                    $.get(settingsUrl,function(data){
                         var str = JSON.stringify(data);
 
                         var configDiv = $('#settingsdiv');
@@ -277,9 +330,9 @@
 
                 //Third section: Summary results table (summary info for each candidate)
                 if(lastResultsUpdateTime != resultsTime){
-
+                    //Get JSON for results table
-                //Get JSON; address set by SummaryResultsResource
+                    var resultsUrl = multiSession ? "/arbiter/" + currSession + "/results" : "/arbiter/results";
-                $.get("/arbiter/results",function(data){
+                    $.get(resultsUrl,function(data){
                         //Expect an array of CandidateInfo type objects here
                         resultsTableContent = data;
                         drawResultTable();
@@ -291,7 +344,10 @@
                 //Finally: Currently selected result
                 if(selectedCandidateIdx != null){
                     //Get JSON for components
-                $.get("/arbiter/candidateInfo/"+selectedCandidateIdx,function(data){
+                    var candidateInfoUrl = multiSession 
+                        ? "/arbiter/" + currSession + "/candidateInfo/" + selectedCandidateIdx
+                        : "/arbiter/candidateInfo/" + selectedCandidateIdx;
+                    $.get(candidateInfoUrl,function(data){
                         var str = JSON.stringify(data);
 
                         var resultsViewDiv = $('#resultsviewdiv');
@@ -302,6 +358,7 @@
                     });
                 }
             })
+        })
     }
 
     function createTable(tableObj,tableId,appendTo){

arbiter/arbiter-ui/src/test/java/org/deeplearning4j/arbiter/optimize/TestBasic.java

@@ -16,6 +16,9 @@
 
 package org.deeplearning4j.arbiter.optimize;
 
+import io.netty.handler.codec.http.HttpResponseStatus;
+import lombok.NonNull;
+import lombok.extern.slf4j.Slf4j;
 import org.deeplearning4j.BaseDL4JTest;
 import org.deeplearning4j.core.storage.StatsStorage;
 import org.deeplearning4j.arbiter.ComputationGraphSpace;
@@ -54,6 +57,7 @@ import org.deeplearning4j.ui.api.UIServer;
 import org.deeplearning4j.ui.model.storage.InMemoryStatsStorage;
 import org.junit.Ignore;
 import org.junit.Test;
+import org.nd4j.common.function.Function;
 import org.nd4j.evaluation.classification.Evaluation;
 import org.nd4j.linalg.activations.Activation;
 import org.nd4j.linalg.api.buffer.DataType;
@@ -62,52 +66,43 @@ import org.nd4j.linalg.factory.Nd4j;
 import org.nd4j.linalg.lossfunctions.LossFunctions;
 
 import java.io.File;
-import java.util.Collections;
+import java.io.IOException;
-import java.util.HashMap;
+import java.io.UnsupportedEncodingException;
-import java.util.Map;
+import java.net.HttpURLConnection;
-import java.util.Properties;
+import java.net.URL;
+import java.net.URLEncoder;
+import java.util.*;
 import java.util.concurrent.TimeUnit;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
 /**
  * Created by Alex on 19/07/2017.
  */
+@Slf4j
 public class TestBasic extends BaseDL4JTest {
 
+    @Override
+    public long getTimeoutMilliseconds() {
+        return 3600_000L;
+    }
+
     @Test
     @Ignore
     public void testBasicUiOnly() throws Exception {
 
         UIServer.getInstance();
 
-        Thread.sleep(1000000);
+        Thread.sleep(1000_000);
     }
 
-
     @Test
     @Ignore
     public void testBasicMnist() throws Exception {
         Nd4j.setDefaultDataTypes(DataType.FLOAT, DataType.FLOAT);
 
-        MultiLayerSpace mls = new MultiLayerSpace.Builder()
+        MultiLayerSpace mls = getMultiLayerSpaceMnist();
-                .updater(new SgdSpace(new ContinuousParameterSpace(0.0001, 0.2)))
-                .l2(new ContinuousParameterSpace(0.0001, 0.05))
-                .addLayer(
-                        new ConvolutionLayerSpace.Builder().nIn(1)
-                                .nOut(new IntegerParameterSpace(5, 30))
-                                .kernelSize(new DiscreteParameterSpace<>(new int[]{3, 3},
-                                        new int[]{4, 4}, new int[]{5, 5}))
-                                .stride(new DiscreteParameterSpace<>(new int[]{1, 1},
-                                        new int[]{2, 2}))
-                                .activation(new DiscreteParameterSpace<>(Activation.RELU,
-                                        Activation.SOFTPLUS, Activation.LEAKYRELU))
-                                .build())
-                .addLayer(new DenseLayerSpace.Builder().nOut(new IntegerParameterSpace(32, 128))
-                        .activation(new DiscreteParameterSpace<>(Activation.RELU, Activation.TANH))
-                        .build(), new IntegerParameterSpace(0, 1), true) //0 to 1 layers
-                .addLayer(new OutputLayerSpace.Builder().nOut(10).activation(Activation.SOFTMAX)
-                        .lossFunction(LossFunctions.LossFunction.MCXENT).build())
-                .setInputType(InputType.convolutionalFlat(28, 28, 1))
-                .build();
         Map<String, Object> commands = new HashMap<>();
 //        commands.put(DataSetIteratorFactoryProvider.FACTORY_KEY, TestDataFactoryProviderMnist.class.getCanonicalName());
 
@@ -144,7 +139,30 @@ public class TestBasic extends BaseDL4JTest {
         UIServer.getInstance().attach(ss);
 
         runner.execute();
-        Thread.sleep(100000);
+        Thread.sleep(1000_000);
+    }
+
+    private static MultiLayerSpace getMultiLayerSpaceMnist() {
+        return new MultiLayerSpace.Builder()
+                .updater(new SgdSpace(new ContinuousParameterSpace(0.0001, 0.2)))
+                .l2(new ContinuousParameterSpace(0.0001, 0.05))
+                .addLayer(
+                        new ConvolutionLayerSpace.Builder().nIn(1)
+                                .nOut(new IntegerParameterSpace(5, 30))
+                                .kernelSize(new DiscreteParameterSpace<>(new int[]{3, 3},
+                                        new int[]{4, 4}, new int[]{5, 5}))
+                                .stride(new DiscreteParameterSpace<>(new int[]{1, 1},
+                                        new int[]{2, 2}))
+                                .activation(new DiscreteParameterSpace<>(Activation.RELU,
+                                        Activation.SOFTPLUS, Activation.LEAKYRELU))
+                                .build())
+                .addLayer(new DenseLayerSpace.Builder().nOut(new IntegerParameterSpace(32, 128))
+                        .activation(new DiscreteParameterSpace<>(Activation.RELU, Activation.TANH))
+                        .build(), new IntegerParameterSpace(0, 1), true) //0 to 1 layers
+                .addLayer(new OutputLayerSpace.Builder().nOut(10).activation(Activation.SOFTMAX)
+                        .lossFunction(LossFunctions.LossFunction.MCXENT).build())
+                .setInputType(InputType.convolutionalFlat(28, 28, 1))
+                .build();
     }
 
     @Test
@@ -233,7 +251,7 @@ public class TestBasic extends BaseDL4JTest {
                 .build();
 
         //Define configuration:
-        CandidateGenerator candidateGenerator = new RandomSearchGenerator(cgs, Collections.EMPTY_MAP);
+        CandidateGenerator candidateGenerator = new RandomSearchGenerator(cgs);
         DataProvider dataProvider = new MnistDataSetProvider();
 
 
@@ -331,7 +349,7 @@ public class TestBasic extends BaseDL4JTest {
         UIServer.getInstance().attach(ss);
 
         runner.execute();
-        Thread.sleep(100000);
+        Thread.sleep(1000_000);
     }
 
 
@@ -396,7 +414,7 @@ public class TestBasic extends BaseDL4JTest {
         UIServer.getInstance().attach(ss);
 
         runner.execute();
-        Thread.sleep(100000);
+        Thread.sleep(1000_000);
     }
 
 
@@ -433,7 +451,7 @@ public class TestBasic extends BaseDL4JTest {
                 .build();
 
         //Define configuration:
-        CandidateGenerator candidateGenerator = new RandomSearchGenerator(cgs, Collections.EMPTY_MAP);
+        CandidateGenerator candidateGenerator = new RandomSearchGenerator(cgs);
         DataProvider dataProvider = new MnistDataSetProvider();
 
 
@@ -465,13 +483,17 @@ public class TestBasic extends BaseDL4JTest {
         UIServer.getInstance().attach(ss);
 
         runner.execute();
-        Thread.sleep(100000);
+        Thread.sleep(1000_000);
     }
 
 
+    /**
+     * Visualize multiple optimization sessions run one after another on single-session mode UI
+     * @throws InterruptedException if current thread has been interrupted
+     */
     @Test
     @Ignore
-    public void testBasicMnistMultipleSessions() throws Exception {
+    public void testBasicMnistMultipleSessions() throws InterruptedException {
 
         MultiLayerSpace mls = new MultiLayerSpace.Builder()
                 .updater(new SgdSpace(new ContinuousParameterSpace(0.0001, 0.2)))
@@ -499,8 +521,10 @@ public class TestBasic extends BaseDL4JTest {
 
         //Define configuration:
         CandidateGenerator candidateGenerator = new RandomSearchGenerator(mls, commands);
-        DataProvider dataProvider = new MnistDataSetProvider();
 
+        Class<? extends DataSource> ds = MnistDataSource.class;
+        Properties dsp = new Properties();
+        dsp.setProperty("minibatch", "8");
 
         String modelSavePath = new File(System.getProperty("java.io.tmpdir"), "ArbiterUiTestBasicMnist\\").getAbsolutePath();
 
@@ -513,7 +537,7 @@ public class TestBasic extends BaseDL4JTest {
 
         OptimizationConfiguration configuration =
                 new OptimizationConfiguration.Builder()
-                        .candidateGenerator(candidateGenerator).dataProvider(dataProvider)
+                        .candidateGenerator(candidateGenerator).dataSource(ds, dsp)
                         .modelSaver(new FileModelSaver(modelSavePath))
                         .scoreFunction(new TestSetLossScoreFunction(true))
                         .terminationConditions(new MaxTimeCondition(1, TimeUnit.MINUTES),
@@ -535,7 +559,7 @@ public class TestBasic extends BaseDL4JTest {
 
         candidateGenerator = new RandomSearchGenerator(mls, commands);
         configuration = new OptimizationConfiguration.Builder()
-                .candidateGenerator(candidateGenerator).dataProvider(dataProvider)
+                .candidateGenerator(candidateGenerator).dataSource(ds, dsp)
                 .modelSaver(new FileModelSaver(modelSavePath))
                 .scoreFunction(new TestSetLossScoreFunction(true))
                 .terminationConditions(new MaxTimeCondition(1, TimeUnit.MINUTES),
@@ -550,7 +574,148 @@ public class TestBasic extends BaseDL4JTest {
 
         runner.execute();
 
-        Thread.sleep(100000);
+        Thread.sleep(1000_000);
+    }
+
+    /**
+     * Auto-attach multiple optimization sessions to multi-session mode UI
+     * @throws IOException if could not connect to the server
+     */
+    @Test
+    public void testUiMultiSessionAutoAttach() throws IOException {
+
+        //Define configuration:
+        MultiLayerSpace mls = getMultiLayerSpaceMnist();
+        CandidateGenerator candidateGenerator = new RandomSearchGenerator(mls);
+
+        Class<? extends DataSource> ds = MnistDataSource.class;
+        Properties dsp = new Properties();
+        dsp.setProperty("minibatch", "8");
+
+        String modelSavePath = new File(System.getProperty("java.io.tmpdir"), "ArbiterUiTestMultiSessionAutoAttach\\")
+                .getAbsolutePath();
+
+        File f = new File(modelSavePath);
+        if (f.exists())
+            f.delete();
+        f.mkdir();
+        if (!f.exists())
+            throw new RuntimeException();
+
+        OptimizationConfiguration configuration =
+                new OptimizationConfiguration.Builder()
+                        .candidateGenerator(candidateGenerator).dataSource(ds, dsp)
+                        .modelSaver(new FileModelSaver(modelSavePath))
+                        .scoreFunction(new TestSetLossScoreFunction(true))
+                        .terminationConditions(new MaxTimeCondition(10, TimeUnit.SECONDS),
+                                new MaxCandidatesCondition(1))
+                        .build();
+
+        IOptimizationRunner runner =
+                new LocalOptimizationRunner(configuration, new MultiLayerNetworkTaskCreator());
+
+        // add 3 different sessions to the same execution
+        HashMap<String, StatsStorage> statsStorageForSession = new HashMap<>();
+        for (int i = 0; i < 3; i++) {
+            StatsStorage ss = new InMemoryStatsStorage();
+            @NonNull String sessionId = "sid" + i;
+            statsStorageForSession.put(sessionId, ss);
+            StatusListener sl = new ArbiterStatusListener(sessionId, ss);
+            runner.addListeners(sl);
+        }
+
+        Function<String, StatsStorage> statsStorageProvider = statsStorageForSession::get;
+        UIServer uIServer = UIServer.getInstance(true, statsStorageProvider);
+        String serverAddress = uIServer.getAddress();
+
+        runner.execute();
+
+        for (String sessionId : statsStorageForSession.keySet()) {
+            /*
+             * Visiting /arbiter/:sessionId to auto-attach StatsStorage
+             */
+            String sessionUrl = sessionUrl(uIServer.getAddress(), sessionId);
+            HttpURLConnection conn = (HttpURLConnection) new URL(sessionUrl).openConnection();
+            conn.connect();
+
+            log.info("Checking auto-attaching Arbiter session at {}", sessionUrl(serverAddress, sessionId));
+            assertEquals(HttpResponseStatus.OK.code(), conn.getResponseCode());
+            assertTrue(uIServer.isAttached(statsStorageForSession.get(sessionId)));
+        }
+    }
+
+    /**
+     * Attach multiple optimization sessions to multi-session mode UI by manually visiting session URL
+     * @throws Exception if an error occurred
+     */
+    @Test
+    @Ignore
+    public void testUiMultiSessionManualAttach() throws Exception {
+        Nd4j.setDefaultDataTypes(DataType.FLOAT, DataType.FLOAT);
+
+        //Define configuration:
+        MultiLayerSpace mls = getMultiLayerSpaceMnist();
+        CandidateGenerator candidateGenerator = new RandomSearchGenerator(mls);
+
+        Class<? extends DataSource> ds = MnistDataSource.class;
+        Properties dsp = new Properties();
+        dsp.setProperty("minibatch", "8");
+
+        String modelSavePath = new File(System.getProperty("java.io.tmpdir"), "ArbiterUiTestBasicMnist\\")
+                .getAbsolutePath();
+
+        File f = new File(modelSavePath);
+        if (f.exists())
+            f.delete();
+        f.mkdir();
+        if (!f.exists())
+            throw new RuntimeException();
+
+        OptimizationConfiguration configuration =
+                new OptimizationConfiguration.Builder()
+                        .candidateGenerator(candidateGenerator).dataSource(ds, dsp)
+                        .modelSaver(new FileModelSaver(modelSavePath))
+                        .scoreFunction(new TestSetLossScoreFunction(true))
+                        .terminationConditions(new MaxTimeCondition(10, TimeUnit.MINUTES),
+                                new MaxCandidatesCondition(10))
+                        .build();
+
+
+        // parallel execution of multiple optimization sessions
+        HashMap<String, StatsStorage> statsStorageForSession = new HashMap<>();
+        for (int i = 0; i < 3; i++) {
+            String sessionId = "sid" + i;
+            IOptimizationRunner runner =
+                    new LocalOptimizationRunner(configuration, new MultiLayerNetworkTaskCreator());
+            StatsStorage ss = new InMemoryStatsStorage();
+            statsStorageForSession.put(sessionId, ss);
+            StatusListener sl = new ArbiterStatusListener(sessionId, ss);
+            runner.addListeners(sl);
+            // Asynchronous execution
+            new Thread(runner::execute).start();
+        }
+
+        Function<String, StatsStorage> statsStorageProvider = statsStorageForSession::get;
+        UIServer uIServer = UIServer.getInstance(true, statsStorageProvider);
+        String serverAddress = uIServer.getAddress();
+
+        for (String sessionId : statsStorageForSession.keySet()) {
+            log.info("Arbiter session can be attached at {}", sessionUrl(serverAddress, sessionId));
+        }
+
+        Thread.sleep(1000_000);
+    }
+
+
+    /**
+     * Get URL for arbiter session on given server address
+     * @param serverAddress server address, e.g.: http://localhost:9000
+     * @param sessionId session ID (will be URL-encoded)
+     * @return URL
+     * @throws UnsupportedEncodingException if the character encoding is not supported
+     */
+    private static String sessionUrl(String serverAddress, String sessionId) throws UnsupportedEncodingException {
+        return String.format("%s/arbiter/%s", serverAddress, URLEncoder.encode(sessionId, "UTF-8"));
     }
 
     private static class MnistDataSetProvider implements DataProvider {

deeplearning4j/deeplearning4j-ui-parent/deeplearning4j-vertx/src/main/java/org/deeplearning4j/ui/VertxUIServer.java

@@ -77,8 +77,6 @@ public class VertxUIServer extends AbstractVerticle implements UIServer {
     private static Integer instancePort;
     private static Thread autoStopThread;
 
-    private TrainModule trainModule;
-
     /**
      * Get (and, initialize if necessary) the UI server. This synchronous function will wait until the server started.
      * @param port TCP socket port for {@link HttpServer} to listen
@@ -194,8 +192,9 @@ public class VertxUIServer extends AbstractVerticle implements UIServer {
         VertxUIServer.autoStopThread = new Thread(() -> {
             try {
                 currentThread.join();
-                log.info("Deeplearning4j UI server is auto-stopping.");
                 if (VertxUIServer.instance != null && !VertxUIServer.instance.isStopped()) {
+                    log.info("Deeplearning4j UI server is auto-stopping after thread (name: {}) died.",
+                            currentThread.getName());
                     instance.stop();
                 }
             } catch (InterruptedException e) {
@@ -207,7 +206,11 @@ public class VertxUIServer extends AbstractVerticle implements UIServer {
 
     private List<UIModule> uiModules = new CopyOnWriteArrayList<>();
     private RemoteReceiverModule remoteReceiverModule;
-    private StatsStorageLoader statsStorageLoader;
+    /**
+     * Loader that attaches {@code StatsStorage} provided by {@code #statsStorageProvider} for the given session ID
+     */
+    @Getter
+    private Function<String, Boolean> statsStorageLoader;
 
     //typeIDModuleMap: Records which modules are registered for which type IDs
     private Map<String, List<UIModule>> typeIDModuleMap = new ConcurrentHashMap<>();
@@ -247,10 +250,23 @@ public class VertxUIServer extends AbstractVerticle implements UIServer {
      */
     public void autoAttachStatsStorageBySessionId(Function<String, StatsStorage> statsStorageProvider) {
         if (statsStorageProvider != null) {
-            this.statsStorageLoader = new StatsStorageLoader(statsStorageProvider);
+            this.statsStorageLoader = (sessionId) -> {
-            if (trainModule != null) {
+                log.info("Loading StatsStorage via StatsStorageProvider for session ID (" + sessionId + ").");
-                this.trainModule.setSessionLoader(this.statsStorageLoader);
+                StatsStorage statsStorage = statsStorageProvider.apply(sessionId);
+                if (statsStorage != null) {
+                    if (statsStorage.sessionExists(sessionId)) {
+                        attach(statsStorage);
+                        return true;
                     }
+                    log.info("Failed to load StatsStorage via StatsStorageProvider for session ID. " +
+                            "Session ID (" + sessionId + ") does not exist in StatsStorage.");
+                    return false;
+                } else {
+                    log.info("Failed to load StatsStorage via StatsStorageProvider for session ID (" + sessionId + "). " +
+                            "StatsStorageProvider returned null.");
+                    return false;
+                }
+            };
         }
     }
 
@@ -302,8 +318,7 @@ public class VertxUIServer extends AbstractVerticle implements UIServer {
         }
 
         uiModules.add(new DefaultModule(isMultiSession())); //For: navigation page "/"
-        trainModule = new TrainModule(isMultiSession(), statsStorageLoader, this::getAddress);
+        uiModules.add(new TrainModule());
-        uiModules.add(trainModule);
         uiModules.add(new ConvolutionalListenerModule());
         uiModules.add(new TsneModule());
         uiModules.add(new SameDiffModule());
@@ -596,37 +611,6 @@ public class VertxUIServer extends AbstractVerticle implements UIServer {
         }
     }
 
-    /**
-     * Loader that attaches {@code StatsStorage} provided by {@code #statsStorageProvider} for the given session ID
-     */
-    private class StatsStorageLoader implements Function<String, Boolean> {
-
-        Function<String, StatsStorage> statsStorageProvider;
-
-        StatsStorageLoader(Function<String, StatsStorage> statsStorageProvider) {
-            this.statsStorageProvider = statsStorageProvider;
-        }
-
-        @Override
-        public Boolean apply(String sessionId) {
-            log.info("Loading StatsStorage via StatsStorageProvider for session ID (" + sessionId + ").");
-            StatsStorage statsStorage = statsStorageProvider.apply(sessionId);
-            if (statsStorage != null) {
-                if (statsStorage.sessionExists(sessionId)) {
-                    attach(statsStorage);
-                    return true;
-                }
-                log.info("Failed to load StatsStorage via StatsStorageProvider for session ID. " +
-                        "Session ID (" + sessionId + ") does not exist in StatsStorage.");
-                return false;
-            } else {
-                log.info("Failed to load StatsStorage via StatsStorageProvider for session ID (" + sessionId + "). " +
-                        "StatsStorageProvider returned null.");
-                return false;
-            }
-        }
-    }
-
     //==================================================================================================================
     // CLI Launcher
 

deeplearning4j/deeplearning4j-ui-parent/deeplearning4j-vertx/src/main/java/org/deeplearning4j/ui/api/UIServer.java

@@ -157,8 +157,9 @@ public interface UIServer {
 
     /**
      * Stop/shut down the UI server. This synchronous function should wait until the server is stopped.
+     * @throws InterruptedException if the current thread is interrupted while waiting
      */
-    void stop() throws Exception;
+    void stop() throws InterruptedException;
 
     /**
      * Stop/shut down the UI server.

deeplearning4j/deeplearning4j-ui-parent/deeplearning4j-vertx/src/main/java/org/deeplearning4j/ui/module/train/TrainModule.java

@@ -26,8 +26,6 @@ import io.vertx.ext.web.RoutingContext;
 import it.unimi.dsi.fastutil.longs.LongArrayList;
 import lombok.AllArgsConstructor;
 import lombok.Data;
-import lombok.Getter;
-import lombok.Setter;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.io.FileUtils;
 import org.apache.commons.io.FilenameUtils;
@@ -43,6 +41,7 @@ import org.deeplearning4j.nn.conf.graph.GraphVertex;
 import org.deeplearning4j.nn.conf.graph.LayerVertex;
 import org.deeplearning4j.nn.conf.layers.*;
 import org.deeplearning4j.nn.conf.serde.JsonMappers;
+import org.deeplearning4j.ui.VertxUIServer;
 import org.deeplearning4j.ui.api.HttpMethod;
 import org.deeplearning4j.ui.api.I18N;
 import org.deeplearning4j.ui.api.Route;
@@ -56,7 +55,6 @@ import org.deeplearning4j.ui.model.stats.api.StatsInitializationReport;
 import org.deeplearning4j.ui.model.stats.api.StatsReport;
 import org.deeplearning4j.ui.model.stats.api.StatsType;
 import org.nd4j.common.function.Function;
-import org.nd4j.common.function.Supplier;
 import org.nd4j.linalg.learning.config.IUpdater;
 import org.nd4j.common.primitives.Pair;
 import org.nd4j.common.primitives.Triple;
@@ -86,8 +84,6 @@ public class TrainModule implements UIModule {
     private static final DecimalFormat df2 = new DecimalFormat("#.00");
     private static DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 
-    private final Supplier<String> addressSupplier;
-
     private enum ModelType {
         MLN, CG, Layer
     }
@@ -99,29 +95,14 @@ public class TrainModule implements UIModule {
     private Map<String, AtomicInteger> workerIdxCount = new ConcurrentHashMap<>(); //Key: session ID
     private Map<String, Map<Integer, String>> workerIdxToName = new ConcurrentHashMap<>(); //Key: session ID
     private Map<String, Long> lastUpdateForSession = new ConcurrentHashMap<>();
-    private final boolean multiSession;
-    @Getter @Setter
-    private Function<String, Boolean> sessionLoader;
 
 
     private final Configuration configuration;
 
-    public TrainModule() {
-        this(false, null, null);
-    }
-
     /**
      * TrainModule
-     *
-     * @param multiSession    multi-session mode
-     * @param sessionLoader   StatsStorage loader to call if an unknown session ID is passed as URL path parameter
-     *                        in multi-session mode
-     * @param addressSupplier supplier for server address (server address in PlayUIServer gets initialized after modules)
      */
-    public TrainModule(boolean multiSession, Function<String, Boolean> sessionLoader, Supplier<String> addressSupplier) {
+    public TrainModule() {
-        this.multiSession = multiSession;
-        this.sessionLoader = sessionLoader;
-        this.addressSupplier = addressSupplier;
         String maxChartPointsProp = System.getProperty(DL4JSystemProperties.CHART_MAX_POINTS_PROPERTY);
         int value = DEFAULT_MAX_CHART_POINTS;
         if (maxChartPointsProp != null) {
@@ -159,8 +140,9 @@ public class TrainModule implements UIModule {
     @Override
     public List<Route> getRoutes() {
         List<Route> r = new ArrayList<>();
-        r.add(new Route("/train/multisession", HttpMethod.GET, (path, rc) -> rc.response().end(multiSession ? "true" : "false")));
+        r.add(new Route("/train/multisession", HttpMethod.GET,
-        if (multiSession) {
+                (path, rc) -> rc.response().end(VertxUIServer.getInstance().isMultiSession() ? "true" : "false")));
+        if (VertxUIServer.getInstance().isMultiSession()) {
             r.add(new Route("/train", HttpMethod.GET, (path, rc) -> this.listSessions(rc)));
             r.add(new Route("/train/:sessionId", HttpMethod.GET, (path, rc) -> {
                 rc.response()
@@ -264,7 +246,9 @@ public class TrainModule implements UIModule {
         if (!knownSessionIDs.isEmpty()) {
             sb.append("        <ul>");
             for (String sessionId : knownSessionIDs.keySet()) {
-                sb.append("            <li><a href=\"train/").append(sessionId).append("\">").append(sessionId).append("</a></li>\n");
+                sb.append("            <li><a href=\"/train/")
+                        .append(sessionId).append("\">")
+                        .append(sessionId).append("</a></li>\n");
             }
             sb.append("        </ul>");
         } else {
@@ -284,9 +268,11 @@ public class TrainModule implements UIModule {
      *
      * @param sessionId  session ID to look fo with provider
      * @param targetPath one of overview / model / system, or null
+     * @param rc routing context
      */
     private void sessionNotFound(String sessionId, String targetPath, RoutingContext rc) {
-        if (sessionLoader != null && sessionLoader.apply(sessionId)) {
+        Function<String, Boolean> loader = VertxUIServer.getInstance().getStatsStorageLoader();
+        if (loader != null && loader.apply(sessionId)) {
             if (targetPath != null) {
                 rc.reroute(targetPath);
             } else {
@@ -306,9 +292,9 @@ public class TrainModule implements UIModule {
                         && StatsListener.TYPE_ID.equals(sse.getTypeID())
                         && !knownSessionIDs.containsKey(sse.getSessionID())) {
                     knownSessionIDs.put(sse.getSessionID(), sse.getStatsStorage());
-                    if (multiSession) {
+                    if (VertxUIServer.getInstance().isMultiSession()) {
                         log.info("Adding training session {}/train/{} of StatsStorage instance {}",
-                                addressSupplier.get(), sse.getSessionID(), sse.getStatsStorage());
+                                VertxUIServer.getInstance().getAddress(), sse.getSessionID(), sse.getStatsStorage());
                     }
                 }
 
@@ -332,9 +318,9 @@ public class TrainModule implements UIModule {
                 if (!StatsListener.TYPE_ID.equals(typeID))
                     continue;
                 knownSessionIDs.put(sessionID, statsStorage);
-                if (multiSession) {
+                if (VertxUIServer.getInstance().isMultiSession()) {
                     log.info("Adding training session {}/train/{} of StatsStorage instance {}",
-                            addressSupplier.get(), sessionID, statsStorage);
+                            VertxUIServer.getInstance().getAddress(), sessionID, statsStorage);
                 }
 
                 List<Persistable> latestUpdates = statsStorage.getLatestUpdateAllWorkers(sessionID, typeID);
@@ -364,9 +350,9 @@ public class TrainModule implements UIModule {
         }
         for (String s : toRemove) {
             knownSessionIDs.remove(s);
-            if (multiSession) {
+            if (VertxUIServer.getInstance().isMultiSession()) {
                 log.info("Removing training session {}/train/{} of StatsStorage instance {}.",
-                        addressSupplier.get(), s, statsStorage);
+                        VertxUIServer.getInstance().getAddress(), s, statsStorage);
             }
             lastUpdateForSession.remove(s);
         }
@@ -602,13 +588,13 @@ public class TrainModule implements UIModule {
     }
 
     /**
-     * Get global {@link I18N} instance if {@link #multiSession} is {@code true}, or instance for session
+     * Get global {@link I18N} instance if {@link VertxUIServer#isMultiSession()} is {@code true}, or instance for session
      *
      * @param sessionId session ID
      * @return {@link I18N} instance
      */
     private I18N getI18N(String sessionId) {
-        return multiSession ? I18NProvider.getInstance(sessionId) : I18NProvider.getInstance();
+        return VertxUIServer.getInstance().isMultiSession() ? I18NProvider.getInstance(sessionId) : I18NProvider.getInstance();
     }
 
 

deeplearning4j/deeplearning4j-ui-parent/deeplearning4j-vertx/src/test/java/org/deeplearning4j/ui/TestVertxUIManual.java

@@ -259,7 +259,7 @@ public class TestVertxUIManual extends BaseDL4JTest {
                         log.info("Auto-detaching StatsStorage (session ID: {}) after {} ms.",
                                 sessionId, autoDetachTimeoutMillis);
                         uIServer.detach(statsStorage);
-                        log.info(" To re-attach StatsStorage of training session, visit {}}/train/{}",
+                        log.info(" To re-attach StatsStorage of training session, visit {}/train/{}",
                                 uIServer.getAddress(), sessionId);
                     }
                 }).start();

deeplearning4j/deeplearning4j-ui-parent/deeplearning4j-vertx/src/test/java/org/deeplearning4j/ui/TestVertxUIMultiSession.java

@@ -197,9 +197,9 @@ public class TestVertxUIMultiSession extends BaseDL4JTest {
     }
 
     /**
-     * Get URL-encoded URL for training session on given server address
+     * Get URL for training session on given server address
      * @param serverAddress server address
-     * @param sessionId session ID
+     * @param sessionId session ID (will be URL-encoded)
      * @return URL
      * @throws UnsupportedEncodingException if the used encoding is not supported
      */