feat: Add Microservice Pattern, Log aggregation (#2690) (#2719)

* feat: Add Microservice Pattern, Log aggregation. Related: #2690 * docs: Add javaDoc for public methods. Related: #2690 --------- Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>
2026-05-15 18:59:10 +00:00 · 2023-12-27 15:06:55 +09:00
parent 5df1fb6f13
commit cd2dbb72d7
12 changed files with 593 additions and 0 deletions
@@ -0,0 +1,120 @@
+/*
+ * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2023 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.logaggregation;
+
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * Responsible for collecting and buffering logs from different services.
+ * Once the logs reach a certain threshold or after a certain time interval,
+ * they are flushed to the central log store. This class ensures logs are collected
+ * and processed asynchronously and efficiently, providing both an immediate collection
+ * and periodic flushing.
+ */
+@Slf4j
+public class LogAggregator {
+
+  private static final int BUFFER_THRESHOLD = 3;
+  private final CentralLogStore centralLogStore;
+  private final ConcurrentLinkedQueue<LogEntry> buffer = new ConcurrentLinkedQueue<>();
+  private final LogLevel minLogLevel;
+  private final ExecutorService executorService = Executors.newSingleThreadExecutor();
+  private final AtomicInteger logCount = new AtomicInteger(0);
+
+  /**
+   * constructor of LogAggregator.
+   *
+   * @param centralLogStore central log store implement
+   * @param minLogLevel min log level to store log
+   */
+  public LogAggregator(CentralLogStore centralLogStore, LogLevel minLogLevel) {
+    this.centralLogStore = centralLogStore;
+    this.minLogLevel = minLogLevel;
+    startBufferFlusher();
+  }
+
+  /**
+   * Collects a given log entry, and filters it by the defined log level.
+   *
+   * @param logEntry The log entry to collect.
+   */
+  public void collectLog(LogEntry logEntry) {
+    if (logEntry.getLevel() == null || minLogLevel == null) {
+      LOGGER.warn("Log level or threshold level is null. Skipping.");
+      return;
+    }
+
+    if (logEntry.getLevel().compareTo(minLogLevel) < 0) {
+      LOGGER.debug("Log level below threshold. Skipping.");
+      return;
+    }
+
+    buffer.offer(logEntry);
+
+    if (logCount.incrementAndGet() >= BUFFER_THRESHOLD) {
+      flushBuffer();
+    }
+  }
+
+  /**
+   * Stops the log aggregator service and flushes any remaining logs to
+   * the central log store.
+   *
+   * @throws InterruptedException If any thread has interrupted the current thread.
+   */
+  public void stop() throws InterruptedException {
+    executorService.shutdownNow();
+    if (!executorService.awaitTermination(10, TimeUnit.SECONDS)) {
+      LOGGER.error("Log aggregator did not terminate.");
+    }
+    flushBuffer();
+  }
+
+  private void flushBuffer() {
+    LogEntry logEntry;
+    while ((logEntry = buffer.poll()) != null) {
+      centralLogStore.storeLog(logEntry);
+      logCount.decrementAndGet();
+    }
+  }
+
+  private void startBufferFlusher() {
+    executorService.execute(() -> {
+      while (!Thread.currentThread().isInterrupted()) {
+        try {
+          Thread.sleep(5000); // Flush every 5 seconds.
+          flushBuffer();
+        } catch (InterruptedException e) {
+          Thread.currentThread().interrupt();
+        }
+      }
+    });
+  }
+}