From 3809b056dc0a5e241f3863777c4c4e5f80776fba Mon Sep 17 00:00:00 2001
From: Andrii Poruchynskyi <aporuchy@cisco.com>
Date: Mon, 6 Jul 2015 15:10:23 +0300
Subject: [PATCH] Fixed #228: Memcached failover in non-sticky mode

---
 .../web/msm/RequestTrackingHostValve.java     |  9 +++++-
 .../web/msm/RequestTrackingHostValveTest.java | 32 +++++++++++++++++++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/core/src/main/java/de/javakaffee/web/msm/RequestTrackingHostValve.java b/core/src/main/java/de/javakaffee/web/msm/RequestTrackingHostValve.java
index 007a99a4..e4b81fb8 100644
--- a/core/src/main/java/de/javakaffee/web/msm/RequestTrackingHostValve.java
+++ b/core/src/main/java/de/javakaffee/web/msm/RequestTrackingHostValve.java
@@ -122,7 +122,7 @@ public void invoke( final Request request, final Response response ) throws IOEx
         final String requestId = getURIWithQueryString( request );
         if(!_enabled.get() || !_msmContext.equals(request.getContext())) {
             getNext().invoke( request, response );
-        } else if ( _ignorePattern != null && _ignorePattern.matcher( requestId ).matches() ) {
+        } else if ( _ignorePattern != null && _ignorePattern.matcher( requestId ).matches() && isPrimaryMemcachedNodeIsAvailable(request)) {
             if(_log.isDebugEnabled()) {
                 _log.debug( ">>>>>> Ignoring: " + requestId + " (requestedSessionId "+ request.getRequestedSessionId() +") ==================" );
             }
@@ -280,4 +280,11 @@ private void logDebugResponseCookie( final Response response ) {
         }
     }
 
+    private boolean isPrimaryMemcachedNodeIsAvailable(Request request) {
+        MemcachedNodesManager memcachedNodesManager = _sessionBackupService.getMemcachedNodesManager();
+        String primaryNodeIdentifier = memcachedNodesManager.getSessionIdFormat().extractMemcachedId(request.getRequestedSessionId());
+        /* In case we have no primary node identifier then primary node is definitely not available for the session */
+        return primaryNodeIdentifier == null ? false : memcachedNodesManager.isNodeAvailable(primaryNodeIdentifier);
+    }
+
 }
diff --git a/core/src/test/java/de/javakaffee/web/msm/RequestTrackingHostValveTest.java b/core/src/test/java/de/javakaffee/web/msm/RequestTrackingHostValveTest.java
index d5827fa1..05d85afe 100644
--- a/core/src/test/java/de/javakaffee/web/msm/RequestTrackingHostValveTest.java
+++ b/core/src/test/java/de/javakaffee/web/msm/RequestTrackingHostValveTest.java
@@ -50,11 +50,18 @@
  */
 public abstract class RequestTrackingHostValveTest {
 
+    private static final String PRIMARY_NODE_IDENTIFIER = "n2";
+    private static final boolean IS_PRIMARY_MEMCACHED_NODE_OPERATIONAL = true;
+    private static final String SESSION_ID = "9956461BA10903169EB0C4041DCA7BF1-n2";
+    private static final String REQUEST_IGNORED = "de.javakaffee.msm.request.ignored";
+
     protected MemcachedSessionService _service;
     private RequestTrackingHostValve _sessionTrackerValve;
     private Valve _nextValve;
     private Request _request;
     private Response _response;
+    private MemcachedNodesManager _memcachedNodesManager;
+    private SessionIdFormat _sessionIdFormat;
 
     @BeforeMethod
     public void setUp() throws Exception {
@@ -75,6 +82,8 @@ public void setUp() throws Exception {
         _nextValve = mock( Valve.class );
         _sessionTrackerValve.setNext( _nextValve );
         _sessionTrackerValve.setContainer(_hostContainer);
+        _memcachedNodesManager = mock( MemcachedNodesManager.class );
+        _sessionIdFormat = mock( SessionIdFormat.class );
 
         when(_request.getRequestURI()).thenReturn( "/someRequest");
         when(_request.getMethod()).thenReturn("GET");
@@ -83,6 +92,11 @@ public void setUp() throws Exception {
 
         when(_request.getNote(eq(RequestTrackingHostValve.REQUEST_PROCESSED))).thenReturn(Boolean.TRUE);
         when(_request.getNote(eq(RequestTrackingHostValve.SESSION_ID_CHANGED))).thenReturn(Boolean.FALSE);
+
+        when(_sessionIdFormat.extractMemcachedId(anyString())).thenReturn(PRIMARY_NODE_IDENTIFIER);
+        when(_service.getMemcachedNodesManager()).thenReturn(_memcachedNodesManager);
+        when(_memcachedNodesManager.isNodeAvailable(PRIMARY_NODE_IDENTIFIER)).thenReturn(IS_PRIMARY_MEMCACHED_NODE_OPERATIONAL);
+        when(_memcachedNodesManager.getSessionIdFormat()).thenReturn(_sessionIdFormat);
     }
 
     @Nonnull
@@ -176,6 +190,24 @@ public final void testRequestFinishedShouldBeInvokedForIgnoredResources() throws
         verify( _service ).requestFinished( eq( "foo" ), anyString() );
     }
 
+    @Test
+    public final void testRequestUrlIgnorePatternIsSkippedIfPrimaryMemcachedNodeIsDown() throws IOException, ServletException {
+        when(_memcachedNodesManager.isNodeAvailable(PRIMARY_NODE_IDENTIFIER)).thenReturn(false);
+        when(_request.getRequestedSessionId()).thenReturn(SESSION_ID);
+        _sessionTrackerValve.invoke( _request, _response );
+
+        verify( _request ).setNote(RequestTrackingHostValve.REQUEST_PROCESS, Boolean.TRUE);
+    }
+
+    @Test
+    public final void testRequestUrlIgnorePatternIsUsedIfPrimaryMemcachedNodeIsOperational() throws IOException, ServletException {
+        when(_memcachedNodesManager.isNodeAvailable(PRIMARY_NODE_IDENTIFIER)).thenReturn(true);
+        when(_request.getRequestURI()).thenReturn("/pixel.gif");
+        _sessionTrackerValve.invoke( _request, _response );
+
+        verify(_request).setNote(REQUEST_IGNORED, Boolean.TRUE);
+    }
+
     protected abstract void setupGetResponseSetCookieHeadersExpectations(Response response, String[] result);
 
     @Nonnull