fixup as fail

Author: Shih-Hao Yeh

evcache-core/src/main/java/com/netflix/evcache/EVCacheImpl.java

@@ -116,6 +116,7 @@ public class EVCacheImpl implements EVCache, EVCacheImplMBean {
 
     private final Property<Boolean> bypassAddOpt;
     private final Property<Boolean> bypassFixup;
+    private final Property<Boolean> fixupAsFail;
 
     EVCacheImpl(String appName, String cacheName, int timeToLive, Transcoder<?> transcoder, boolean enableZoneFallback,
             boolean throwException, EVCacheClientPoolManager poolManager) {
@@ -176,6 +177,7 @@ public class EVCacheImpl implements EVCache, EVCacheImplMBean {
         // bypass short-circuit optimization
         this.bypassAddOpt = propertyRepository.get(_appName + ".bypass.add.opt", Boolean.class).orElse(false);
         this.bypassFixup = propertyRepository.get(_appName + ".bypass.fixup", Boolean.class).orElse(false);
+        this.fixupAsFail = propertyRepository.get(_appName + ".fixup.as.fail", Boolean.class).orElse(false);
 
         // if alias changes, refresh my pool to point to the correct alias app
         this.alias = propertyRepository.get("EVCacheClientPoolManager." + appName + ".alias", String.class);
@@ -3329,7 +3331,7 @@ protected <T> EVCacheLatch add(String key, T value, Transcoder<T> tc, int timeTo
                 cd = _pool.getEVCacheClientForRead().getTranscoder().encode(value);
             }
             if (clientUtil == null) clientUtil = new EVCacheClientUtil(_appName, _pool.getOperationTimeout().get());
-            latch = clientUtil.add(evcKey, cd, evcacheValueTranscoder, timeToLive, policy, clients, latchCount, fixup, bypassAddOpt.get());
+            latch = clientUtil.add(evcKey, cd, evcacheValueTranscoder, timeToLive, policy, clients, latchCount, fixup, bypassAddOpt.get(), fixupAsFail.get());
             if (event != null) {
                 event.setTTL(timeToLive);
                 event.setCachedData(cd);

evcache-core/src/main/java/com/netflix/evcache/pool/EVCacheClientUtil.java

@@ -49,7 +49,7 @@ public EVCacheClientUtil(String appName, long operationTimeout) {
     /**
      * TODO : once metaget is available we need to get the remaining ttl from an existing entry and use it
      */
-    public EVCacheLatch add(EVCacheKey evcKey, final CachedData cd, Transcoder evcacheValueTranscoder, int timeToLive, Policy policy, final EVCacheClient[] clients, int latchCount, boolean fixMissing, boolean bypassAddOpt) throws Exception {
+    public EVCacheLatch add(EVCacheKey evcKey, final CachedData cd, Transcoder evcacheValueTranscoder, int timeToLive, Policy policy, final EVCacheClient[] clients, int latchCount, boolean fixMissing, boolean bypassAddOpt, boolean fixupAsFail) throws Exception {
         if (cd == null) return null;
 
         final EVCacheLatchImpl latch = new EVCacheLatchImpl(policy, latchCount, _appName);
@@ -83,11 +83,11 @@ public EVCacheLatch add(EVCacheKey evcKey, final CachedData cd, Transcoder evcac
                             return latch;
                         }
                         else {
-                            return fixup(client, clients, evcKey, timeToLive, policy);
+                            return fixup(client, clients, evcKey, timeToLive, policy, latch, fixupAsFail);
                         }
                     } else {
                         if (log.isDebugEnabled()) log.debug("Add failed after first client. key: " + key + ", client : " + client);
-                        return fixup(client, clients, evcKey, timeToLive, policy);
+                        return fixup(client, clients, evcKey, timeToLive, policy, latch, fixupAsFail);
                     }
                 }
                 if(firstStatus == null) firstStatus = Boolean.valueOf(status);
@@ -96,7 +96,7 @@ public EVCacheLatch add(EVCacheKey evcKey, final CachedData cd, Transcoder evcac
         return latch;
     }
 
-    private EVCacheLatch fixup(EVCacheClient sourceClient, EVCacheClient[] destClients, EVCacheKey evcKey, int timeToLive, Policy policy) {
+    private EVCacheLatch fixup(EVCacheClient sourceClient, EVCacheClient[] destClients, EVCacheKey evcKey, int timeToLive, Policy policy, EVCacheLatchImpl prevLatch, boolean fixupAsFail) {
         if (log.isDebugEnabled()) log.debug("Trying to fix up!! destClient count = " + destClients.length);
         final EVCacheLatchImpl latch = new EVCacheLatchImpl(policy, destClients.length, _appName);
         try {
@@ -110,7 +110,16 @@ private EVCacheLatch fixup(EVCacheClient sourceClient, EVCacheClient[] destClien
             }
             latch.await(_operationTimeout, TimeUnit.MILLISECONDS);
         } catch (Exception e) {
-            log.error("Error reading the data", e);
+            log.error("Error fixing up the data.", e);
+        }
+
+        // We still do our best to fixup, but client should know the key exist before the Add
+        if (fixupAsFail) {
+            for (int i = 0; i < destClients.length; i++) {
+                prevLatch.countDown();
+            }
+            if (log.isDebugEnabled()) log.debug("Fixup treated as fail. latchSuccess = " + prevLatch.getSuccessCount() + ", latchExpected = " + prevLatch.getExpectedSuccessCount());
+            return prevLatch;
         }
         return latch;
     }