Make linearly executing workers start at different positions (#286)

* Update LinearQuerySelector to also accept starting index

* Fix minor bug concerning failed results

* Update QueryHandler and Stresstest to give each worker a starting index when executing queries linearly

* Fix the initialization of the query handlers

* Add simple test

* Remove unused variable

* Add comment back about LinearQuerySelector indexing

Closes #193

src/main/java/org/aksw/iguana/cc/query/handler/QueryHandler.java

@@ -157,6 +157,7 @@ public record QueryStreamWrapper(int index, boolean cached, Supplier<InputStream
     final protected QueryList queryList;
 
     private int workerCount = 0; // give every worker inside the same worker config an offset seed
+    private int totalWorkerCount = 0;
 
     final protected int hashCode;
 
@@ -186,6 +187,10 @@ public QueryHandler(Config config) throws IOException {
         this.hashCode = queryList.hashCode();
     }
 
+    public void setTotalWorkerCount(int workers) {
+        this.totalWorkerCount = workers;
+    }
+
     private QueryList initializeTemplateQueryHandler(QuerySource templateSource) throws IOException {
         QuerySource querySource = templateSource;
         final var originalPath = templateSource.getPath();
@@ -238,7 +243,7 @@ private QuerySource createQuerySource(Path path) throws IOException {
 
     public QuerySelector getQuerySelectorInstance() {
         switch (config.order()) {
-            case LINEAR -> { return new LinearQuerySelector(queryList.size()); }
+            case LINEAR -> { return new LinearQuerySelector(queryList.size(), totalWorkerCount != 0 ? (queryList.size() * workerCount++) / totalWorkerCount : 0); }
             case RANDOM -> { return new RandomQuerySelector(queryList.size(), config.seed() + workerCount++); }
         }
 

src/main/java/org/aksw/iguana/cc/query/selector/impl/LinearQuerySelector.java

@@ -14,25 +14,30 @@ public class LinearQuerySelector extends QuerySelector {
 
     public LinearQuerySelector(int size) {
         super(size);
-        index = -1;
+        index = 0;
+    }
+
+    public LinearQuerySelector(int size, int startIndex) {
+        super(size);
+        index = startIndex;
     }
 
     @Override
     public int getNextIndex() {
-        index++;
         if (index >= this.size) {
             index = 0;
         }
-        return index;
+        return index++;
     }
 
     /**
-     * Return the current index. This is the index of the last returned query. If no query was returned yet, it returns
-     * -1.
-     * @return
+     * Return the current index. This is the index of the last returned query.
+     * If no query was returned yet, the method will return -1.
+     *
+     * @return the current index
      */
     @Override
     public int getCurrentIndex() {
-        return index;
+        return index - 1;
     }
 }

src/main/java/org/aksw/iguana/cc/tasks/impl/Stresstest.java

@@ -2,6 +2,7 @@
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 import org.aksw.iguana.cc.metrics.Metric;
+import org.aksw.iguana.cc.query.handler.QueryHandler;
 import org.aksw.iguana.cc.storage.Storage;
 import org.aksw.iguana.cc.tasks.Task;
 import org.aksw.iguana.cc.worker.HttpWorker;
@@ -44,6 +45,15 @@ public Stresstest(String suiteID, long stresstestID, Config config, ResponseBody
 
         // initialize workers
         if (config.warmupWorkers() != null) {
+            // initialize query handlers
+            // count the number of workers for each query handler
+            final var queryHandlers = config.warmupWorkers.stream().map(HttpWorker.Config::queries).distinct().toList();
+            queryHandlers.stream().map(qh1 ->
+                            List.of(qh1, config.warmupWorkers.stream()
+                                    .map(HttpWorker.Config::queries)
+                                    .filter(qh1::equals)
+                                    .count()))
+                    .forEach(list -> ((QueryHandler) list.get(0)).setTotalWorkerCount((int) (long) list.get(1)));
             long workerId = 0;
             for (HttpWorker.Config workerConfig : config.warmupWorkers()) {
                 for (int i = 0; i < workerConfig.number(); i++) {
@@ -54,6 +64,15 @@ public Stresstest(String suiteID, long stresstestID, Config config, ResponseBody
         }
 
         for (HttpWorker.Config workerConfig : config.workers()) {
+            // initialize query handlers
+            // count the number of workers for each query handler
+            final var queryHandlers = config.workers.stream().map(HttpWorker.Config::queries).distinct().toList();
+            queryHandlers.stream().map(qh1 ->
+                            List.of(qh1, config.workers.stream()
+                                    .filter(w -> w.queries().equals(qh1))
+                                    .mapToInt(HttpWorker.Config::number)
+                                    .sum()))
+                    .forEach(list -> ((QueryHandler) list.get(0)).setTotalWorkerCount((int) list.get(1)));
             long workerId = 0;
             for (int i = 0; i < workerConfig.number(); i++) {
                 var responseBodyProcessor = (workerConfig.parseResults()) ? responseBodyProcessorInstances.getProcessor(workerConfig.acceptHeader()) : null;
@@ -83,10 +102,9 @@ public Stresstest(String suiteID, long stresstestID, Config config, ResponseBody
     public void run() {
         if (!warmupWorkers.isEmpty()) {
             SPARQLProtocolWorker.initHttpClient(warmupWorkers.size());
-            var warmupResults = executeWorkers(warmupWorkers); // warmup results will be dismissed
+            executeWorkers(warmupWorkers); // warmup results will be dismissed
             SPARQLProtocolWorker.closeHttpClient();
         }
-
         SPARQLProtocolWorker.initHttpClient(workers.size());
         var results = executeWorkers(workers);
         SPARQLProtocolWorker.closeHttpClient();

src/main/java/org/aksw/iguana/cc/worker/impl/SPARQLProtocolWorker.java

@@ -270,7 +270,7 @@ private HttpExecutionResult executeHttpRequest(Duration timeout) {
         try {
             request = requestFactory.buildHttpRequest(queryHandle);
         } catch (IOException | URISyntaxException e) {
-            return createFailedResultBeforeRequest(config.queries().getQuerySelectorInstance().getCurrentIndex(), e);
+            return createFailedResultBeforeRequest(querySelector.getCurrentIndex(), e);
         }
 
         // execute the request

src/test/java/org/aksw/iguana/cc/query/selector/impl/LinearQuerySelectorTest.java

@@ -26,4 +26,18 @@ public void ThrowOnLinearQuerySelectorSizeZero() {
         final var size = 0;
         assertThrows(IllegalArgumentException.class, () -> new LinearQuerySelector(size));
     }
+
+    @Test
+    public void testStartingIndex() {
+        final var size = 5;
+        final var startIndex = 3;
+        final var linearQuerySelector = new LinearQuerySelector(size, startIndex);
+        // -1, because the next index hasn't been requested yet
+        assertEquals(startIndex - 1, linearQuerySelector.getCurrentIndex());
+        for (int i = 0; i < 10; i++) {
+            int currentIndex = linearQuerySelector.getNextIndex();
+            assertEquals((i + startIndex) % size, currentIndex);
+            assertEquals(currentIndex, linearQuerySelector.getCurrentIndex());
+        }
+    }
 }