Add a new interface, DefaultRequestLogStrategy, to disable requestL…

…og for the concurrency strategy.

This adds an opt-in interface to allow concurrency strategies to
behave like the default concurrency strategy.

hystrix-core/src/main/java/com/netflix/hystrix/AbstractCommand.java

@@ -27,6 +27,7 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
+import com.netflix.hystrix.strategy.concurrency.DefaultRequestLogStrategy;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -258,7 +259,7 @@ protected AbstractCommand(HystrixCommandGroupKey group, HystrixCommandKey key, H
         this.requestCache = HystrixRequestCache.getInstance(this.commandKey, this.concurrencyStrategy);
 
         /* store reference to request log regardless of which thread later hits it */
-        if (concurrencyStrategy instanceof HystrixConcurrencyStrategyDefault) {
+        if (concurrencyStrategy instanceof DefaultRequestLogStrategy) {
             // if we're using the default we support only optionally using a request context
             if (HystrixRequestContext.isCurrentThreadInitialized()) {
                 currentRequestLog = HystrixRequestLog.getCurrentRequest(concurrencyStrategy);

hystrix-core/src/main/java/com/netflix/hystrix/strategy/concurrency/DefaultRequestLogStrategy.java

@@ -0,0 +1,8 @@
+package com.netflix.hystrix.strategy.concurrency;
+
+/**
+ * Indicates that the HystrixConcurrencyStrategy does not use a custom request log,
+ * therefore threads do not need to initialize the request log.
+ */
+public interface DefaultRequestLogStrategy {
+}

hystrix-core/src/main/java/com/netflix/hystrix/strategy/concurrency/HystrixConcurrencyStrategyDefault.java

@@ -20,7 +20,7 @@
  * 
  * @ExcludeFromJavadoc
  */
-public class HystrixConcurrencyStrategyDefault extends HystrixConcurrencyStrategy {
+public class HystrixConcurrencyStrategyDefault extends HystrixConcurrencyStrategy implements DefaultRequestLogStrategy {
 
     private static HystrixConcurrencyStrategyDefault INSTANCE = new HystrixConcurrencyStrategyDefault();