Remove multithreading from module sync watchdog

After introduction of module set tag improvements, there is no need
to multithreading in module sync. Performance impact is minimal.

Issue-ID: CPS-2165
Signed-off-by: danielhanrahan <daniel.hanrahan@est.tech>
Change-Id: I1557fc8348d39da3654a1b92944c6ad49fa8670d

4 files changed, 7 insertions, 154 deletions

diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/AsyncTaskExecutor.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/AsyncTaskExecutor.java
deleted file mode 100644
index 80bc4ab69f..0000000000
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/AsyncTaskExecutor.java
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- *  ============LICENSE_START=======================================================
- *  Copyright (C) 2022-2024 Nordix Foundation
- *  ================================================================================
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *        http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *
- *  SPDX-License-Identifier: Apache-2.0
- *  ============LICENSE_END=========================================================
- */
-
-package org.onap.cps.ncmp.impl.inventory.sync;
-
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-
-import jakarta.annotation.PostConstruct;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeoutException;
-import java.util.function.Supplier;
-import lombok.Getter;
-import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Value;
-import org.springframework.stereotype.Service;
-
-@Slf4j
-@Service
-public class AsyncTaskExecutor {
-
-    @Value("${ncmp.modules-sync-watchdog.async-executor.parallelism-level:10}")
-    @Getter
-    private int asyncTaskParallelismLevel;
-    private ExecutorService executorService;
-    private static final int DEFAULT_PARALLELISM_LEVEL = 10;
-
-    /**
-     *  Set up executor service with thread-pool size as per configuration parameter.
-     *  If modules-sync-watchdog.async-executor.parallelism-level not set a default of 10 threads will be applied.
-     */
-    @PostConstruct
-    public void setupThreadPool() {
-        executorService = Executors.newWorkStealingPool(
-                asyncTaskParallelismLevel == 0 ? DEFAULT_PARALLELISM_LEVEL : asyncTaskParallelismLevel);
-    }
-
-    /**
-     * Execute supplied task asynchronously.
-     *
-     * @param taskSupplier    functional method is get() task need to executed asynchronously
-     * @param timeOutInMillis the task timeout value in milliseconds
-     */
-    public void executeTask(final Supplier<Object> taskSupplier, final long timeOutInMillis) {
-        CompletableFuture.supplyAsync(taskSupplier::get, executorService)
-                .orTimeout(timeOutInMillis, MILLISECONDS)
-                .whenCompleteAsync(this::handleTaskCompletion);
-    }
-
-    private void handleTaskCompletion(final Object response, final Throwable throwable) {
-        if (throwable != null) {
-            if (throwable instanceof TimeoutException) {
-                log.error("Async task didn't complete within the required time.", throwable);
-            } else {
-                log.error("Watchdog async batch failed.", throwable);
-            }
-        }
-    }
-}
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/ModuleSyncTasks.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/ModuleSyncTasks.java
index f039cf3c02..b727e79e70 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/ModuleSyncTasks.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/ModuleSyncTasks.java
@@ -24,8 +24,6 @@ import com.hazelcast.map.IMap;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.atomic.AtomicInteger;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.onap.cps.api.exceptions.DataNodeNotFoundException;
@@ -51,12 +49,8 @@ public class ModuleSyncTasks {
      * Perform module sync on a batch of cm handles.
      *
      * @param cmHandleIds                  a batch of cm handle ids to perform module sync on
-     * @param batchCounter                 the number of batches currently being processed, will be decreased when
-     *                                     task is finished or fails
-     * @return completed future to handle post-processing
      */
-    public CompletableFuture<Void> performModuleSync(final Collection<String> cmHandleIds,
-                                                     final AtomicInteger batchCounter) {
+    public void performModuleSync(final Collection<String> cmHandleIds) {
         final Map<YangModelCmHandle, CmHandleState> cmHandleStatePerCmHandle = new HashMap<>(cmHandleIds.size());
         try {
             for (final String cmHandleId : cmHandleIds) {
@@ -74,11 +68,8 @@ public class ModuleSyncTasks {
                 }
             }
         } finally {
-            batchCounter.getAndDecrement();
             lcmEventsCmHandleStateHandler.updateCmHandleStateBatch(cmHandleStatePerCmHandle);
-            log.info("Processing module sync batch finished. {} batch(es) active.", batchCounter.get());
         }
-        return CompletableFuture.completedFuture(null);
     }
 
     /**
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/ModuleSyncWatchdog.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/ModuleSyncWatchdog.java
index 32e1c49f17..6eefedb633 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/ModuleSyncWatchdog.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/inventory/sync/ModuleSyncWatchdog.java
@@ -1,6 +1,6 @@
 /*
  *  ============LICENSE_START=======================================================
- *  Copyright (C) 2022-2024 Nordix Foundation
+ *  Copyright (C) 2022-2025 Nordix Foundation
  *  Modifications Copyright (C) 2022 Bell Canada
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -27,13 +27,9 @@ import com.hazelcast.map.IMap;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.concurrent.BlockingQueue;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicInteger;
-import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.onap.cps.ncmp.impl.inventory.models.YangModelCmHandle;
-import org.onap.cps.ncmp.impl.utils.Sleeper;
 import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Service;
 
@@ -46,16 +42,10 @@ public class ModuleSyncWatchdog {
     private final BlockingQueue<String> moduleSyncWorkQueue;
     private final IMap<String, Object> moduleSyncStartedOnCmHandles;
     private final ModuleSyncTasks moduleSyncTasks;
-    private final AsyncTaskExecutor asyncTaskExecutor;
     private final IMap<String, String> cpsAndNcmpLock;
-    private final Sleeper sleeper;
 
     private static final int MODULE_SYNC_BATCH_SIZE = 100;
-    private static final long PREVENT_CPU_BURN_WAIT_TIME_MILLIS = 10;
     private static final String VALUE_FOR_HAZELCAST_IN_PROGRESS_MAP = "Started";
-    private static final long ASYNC_TASK_TIMEOUT_IN_MILLISECONDS = TimeUnit.MINUTES.toMillis(5);
-    @Getter
-    private AtomicInteger batchCounter = new AtomicInteger(1);
 
     /**
      * Check DB for any cm handles in 'ADVISED' state.
@@ -69,18 +59,11 @@ public class ModuleSyncWatchdog {
         log.debug("Processing module sync watchdog waking up.");
         populateWorkQueueIfNeeded();
         while (!moduleSyncWorkQueue.isEmpty()) {
-            if (batchCounter.get() <= asyncTaskExecutor.getAsyncTaskParallelismLevel()) {
-                final Collection<String> nextBatch = prepareNextBatch();
-                log.info("Processing module sync batch of {}. {} batch(es) active.",
-                    nextBatch.size(), batchCounter.get());
-                if (!nextBatch.isEmpty()) {
-                    asyncTaskExecutor.executeTask(() ->
-                            moduleSyncTasks.performModuleSync(nextBatch, batchCounter),
-                        ASYNC_TASK_TIMEOUT_IN_MILLISECONDS);
-                    batchCounter.getAndIncrement();
-                }
-            } else {
-                preventBusyWait();
+            final Collection<String> nextBatch = prepareNextBatch();
+            if (!nextBatch.isEmpty()) {
+                log.info("Processing module sync batch of {}. 1 batch(es) active.", nextBatch.size());
+                moduleSyncTasks.performModuleSync(nextBatch);
+                log.info("Processing module sync batch finished. 0 batch(es) active.");
             }
         }
     }
@@ -153,13 +136,4 @@ public class ModuleSyncWatchdog {
         log.info("nextBatch size : {}", nextBatch.size());
         return nextBatch;
     }
-
-    private void preventBusyWait() {
-        try {
-            log.debug("Busy waiting now");
-            sleeper.haveALittleRest(PREVENT_CPU_BURN_WAIT_TIME_MILLIS);
-        } catch (final InterruptedException e) {
-            Thread.currentThread().interrupt();
-        }
-    }
 }
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/utils/Sleeper.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/utils/Sleeper.java
deleted file mode 100644
index 7a02fa06e0..0000000000
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/impl/utils/Sleeper.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- *  ============LICENSE_START=======================================================
- *  Copyright (C) 2024 Nordix Foundation
- *  ================================================================================
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *        http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *
- *  SPDX-License-Identifier: Apache-2.0
- *  ============LICENSE_END=========================================================
- */
-
-package org.onap.cps.ncmp.impl.utils;
-
-import java.util.concurrent.TimeUnit;
-import org.springframework.stereotype.Service;
-
-/**
- * This class is to extract out sleep functionality so the interrupted exception handling can
- * be covered with a test (e.g. using spy on Sleeper) and help to get to 100% code coverage.
- */
-@Service
-public class Sleeper {
-    public void haveALittleRest(final long timeInMillis) throws InterruptedException {
-        TimeUnit.MILLISECONDS.sleep(timeInMillis);
-    }
-}