Limit the number of concurrent queries to the QUEUE table / setStatus

src/main/java/alien/taskQueue/TaskQueueUtils.java

@@ -28,6 +28,7 @@ import java.util.StringTokenizer;
 import java.util.TreeMap;
 import java.util.Vector;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -670,6 +671,8 @@ public class TaskQueueUtils {
 
 	private static ApMon centralMLService = null;
 
+	private static final Semaphore limiter = new Semaphore(ConfigUtils.getConfig().geti("alien.taskQueue.TaskQueueUtils.setJobStatus_semaphores", 10), true);
+
 	/**
 	 * @param job
 	 * @param newStatus
@@ -705,13 +708,25 @@ public class TaskQueueUtils {
 
 			final int queryRetriesMax = 3;
 			for (int retries = 0;; retries++) {
-				if (!db.query(q, false, Long.valueOf(job))) {
-					logger.log(Level.SEVERE, "Error executing the select query from QUEUE");
-					if (retries == queryRetriesMax - 1)
-						return false;
+				try {
+					limiter.acquire();
+				}
+				catch (@SuppressWarnings("unused") final InterruptedException e) {
+					return false;
+				}
+
+				try {
+					if (!db.query(q, false, Long.valueOf(job))) {
+						logger.log(Level.SEVERE, "Error executing the select query from QUEUE");
+						if (retries == queryRetriesMax - 1)
+							return false;
+					}
+					else
+						break;
+				}
+				finally {
+					limiter.release();
 				}
-				else
-					break;
 			}
 
 			if (!db.moveNext()) {
@@ -760,12 +775,24 @@ public class TaskQueueUtils {
 			db.setQueryTimeout(600);
 
 			for (int retries = 0;; retries++) {
-				if (!db.query(q, false, newstatus, Long.valueOf(job))) {
-					if (retries == queryRetriesMax - 1)
-						return false;
+				try {
+					limiter.acquire();
+				}
+				catch (@SuppressWarnings("unused") final InterruptedException e) {
+					return false;
+				}
+
+				try {
+					if (!db.query(q, false, newstatus, Long.valueOf(job))) {
+						if (retries == queryRetriesMax - 1)
+							return false;
+					}
+					else
+						break;
+				}
+				finally {
+					limiter.release();
 				}
-				else
-					break;
 			}
 
 			final boolean updated = db.getUpdateCount() != 0;
@@ -2726,7 +2753,7 @@ public class TaskQueueUtils {
 
 		/**
 		 * @param key
-		 * 
+		 *
 		 */
 		public LookupTable(final String key) {
 			query = "SELECT " + key.toLowerCase() + "id FROM QUEUE_" + key + " WHERE " + key.toLowerCase() + "=?";
@@ -2739,7 +2766,7 @@ public class TaskQueueUtils {
 		}
 
 		@Override
-		protected Integer resolve(String key) {
+		protected Integer resolve(final String key) {
 			try (DBFunctions db = getQueueDB()) {
 				if (db == null)
 					return null;
@@ -2772,9 +2799,9 @@ public class TaskQueueUtils {
 	 * @return value for this key
 	 */
 	public static int getOrInsertFromLookupTable(final String key, final String value) {
-		LookupTable cache = lookupTable.computeIfAbsent(key.toUpperCase(), (k) -> new LookupTable(k));
+		final LookupTable cache = lookupTable.computeIfAbsent(key.toUpperCase(), (k) -> new LookupTable(k));
 
-		Integer i = cache.get(value);
+		final Integer i = cache.get(value);
 
 		if (i != null)
 			return i.intValue();