Change executor service defaults (#242)

- Set the default core and maximum thread pool size to Runtime.getRuntime().availableProcessors() + 1.
- Use a fixed thread pool using the larger of core or maximum thread pool, and an unbounded queue to prevent failures submitting work when all threads are in use.
- Make HFClient.getExecutorService() public.

The default (effectively) unlimited thread pool size with blocking queue could cause so many threads to be created under high event load that system failures could occur.

Signed-off-by: Mark S. Lewis <[email protected]>

Author: bestbeforetoday

src/main/java/org/hyperledger/fabric/sdk/HFClient.java

@@ -28,9 +28,7 @@
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
-import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.ThreadFactory;
-import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -66,18 +64,15 @@ public class HFClient {
         }
     }
 
-    ExecutorService getExecutorService() {
+    public ExecutorService getExecutorService() {
         if (null == executorService) {
             synchronized (this) { //was null so lets get a lock for safe update.
                 if (null == executorService) { // no other thread has done it ...
-                    executorService = new ThreadPoolExecutor(CLIENT_THREAD_EXECUTOR_COREPOOLSIZE, CLIENT_THREAD_EXECUTOR_MAXIMUMPOOLSIZE,
-                            CLIENT_THREAD_EXECUTOR_KEEPALIVETIME, CLIENT_THREAD_EXECUTOR_KEEPALIVETIMEUNIT,
-                            new SynchronousQueue<>(),
-                            r -> {
-                                Thread t = threadFactory.newThread(r);
-                                t.setDaemon(true);
-                                return t;
-                            });
+                    executorService = Executors.newFixedThreadPool(CLIENT_THREAD_EXECUTOR_POOLSIZE, r -> {
+                        Thread t = threadFactory.newThread(r);
+                        t.setDaemon(true);
+                        return t;
+                    });
                 }
             }
 
@@ -97,10 +92,7 @@ public User getUserContext() {
 
     protected final ThreadFactory threadFactory = Executors.defaultThreadFactory();
 
-    private static final int CLIENT_THREAD_EXECUTOR_COREPOOLSIZE = config.getClientThreadExecutorCorePoolSize();
-    private static final int CLIENT_THREAD_EXECUTOR_MAXIMUMPOOLSIZE = config.getClientThreadExecutorMaxiumPoolSize();
-    private static final long CLIENT_THREAD_EXECUTOR_KEEPALIVETIME = config.getClientThreadExecutorKeepAliveTime();
-    private static final TimeUnit CLIENT_THREAD_EXECUTOR_KEEPALIVETIMEUNIT = config.getClientThreadExecutorKeepAliveTimeUnit();
+    private static final int CLIENT_THREAD_EXECUTOR_POOLSIZE = Math.max(config.getClientThreadExecutorCorePoolSize(), config.getClientThreadExecutorMaxiumPoolSize());
 
     private HFClient() {
     }

src/main/java/org/hyperledger/fabric/sdk/helper/Config.java

@@ -25,9 +25,7 @@
 
 import io.opentelemetry.api.OpenTelemetry;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
-import io.opentelemetry.sdk.OpenTelemetrySdkBuilder;
 import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdk;
-import io.opentelemetry.sdk.trace.SdkTracerProvider;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.log4j.Level;
@@ -182,9 +180,10 @@ private Config() {
              * Default HFClient thread executor settings.
              */
 
-            defaultProperty(CLIENT_THREAD_EXECUTOR_COREPOOLSIZE, "0");
-            defaultProperty(CLIENT_THREAD_EXECUTOR_MAXIMUMPOOLSIZE, "" + Integer.MAX_VALUE);
-            defaultProperty(CLIENT_THREAD_EXECUTOR_KEEPALIVETIME, "" + "60");
+            int availableProcessors = Runtime.getRuntime().availableProcessors();
+            defaultProperty(CLIENT_THREAD_EXECUTOR_COREPOOLSIZE, Integer.toString(availableProcessors + 1));
+            defaultProperty(CLIENT_THREAD_EXECUTOR_MAXIMUMPOOLSIZE, Integer.toString(availableProcessors + 1));
+            defaultProperty(CLIENT_THREAD_EXECUTOR_KEEPALIVETIME, "60");
             defaultProperty(CLIENT_THREAD_EXECUTOR_KEEPALIVETIMEUNIT, "SECONDS");
 
             /**