ZOOKEEPER-3072: Throttle race condition fix

Making the throttle check before passing over the request to the next thread will prevent the possibility of throttling code running after unthrottle Added an additional async hammer thread which is pretty reliably reproduces the race condition. The globalOutstandingLimit is decreased so throttling code is executed. Author: Botond Hejj <[email protected]> Reviewers: Andor Molnár <[email protected]>, Norbert Kalmar <[email protected]>, Benjamin Reed <[email protected]> Closes apache#563 from bothejjms/ZOOKEEPER-3072
RokLenarcic · Jul 28, 2018 · 2a372fc · 2a372fc
1 parent 726587e
commit 2a372fc
Showing 1 changed file with 14 additions and 16 deletions.
diff --git a/src/java/main/org/apache/zookeeper/server/ZooKeeperServer.java b/src/java/main/org/apache/zookeeper/server/ZooKeeperServer.java
@@ -1130,24 +1130,22 @@ public void processPacket(ServerCnxn cnxn, ByteBuffer incomingBuffer) throws IOE
                 cnxn.disableRecv();
             }
             return;
+        } else if (h.getType() == OpCode.sasl) {
+            Record rsp = processSasl(incomingBuffer,cnxn);
+            ReplyHeader rh = new ReplyHeader(h.getXid(), 0, KeeperException.Code.OK.intValue());
+            cnxn.sendResponse(rh,rsp, "response"); // not sure about 3rd arg..what is it?
+            return;
         } else {
-            if (h.getType() == OpCode.sasl) {
-                Record rsp = processSasl(incomingBuffer,cnxn);
-                ReplyHeader rh = new ReplyHeader(h.getXid(), 0, KeeperException.Code.OK.intValue());
-                cnxn.sendResponse(rh,rsp, "response"); // not sure about 3rd arg..what is it?
-                return;
-            }
-            else {
-                Request si = new Request(cnxn, cnxn.getSessionId(), h.getXid(),
-                  h.getType(), incomingBuffer, cnxn.getAuthInfo());
-                si.setOwner(ServerCnxn.me);
-                // Always treat packet from the client as a possible
-                // local request.
-                setLocalSessionFlag(si);
-                submitRequest(si);
-            }
+            cnxn.incrOutstandingRequests(h);
+            Request si = new Request(cnxn, cnxn.getSessionId(), h.getXid(),
+              h.getType(), incomingBuffer, cnxn.getAuthInfo());
+            si.setOwner(ServerCnxn.me);
+            // Always treat packet from the client as a possible
+            // local request.
+            setLocalSessionFlag(si);
+            submitRequest(si);
+            return;
         }
-        cnxn.incrOutstandingRequests(h);
     }
 
     private Record processSasl(ByteBuffer incomingBuffer, ServerCnxn cnxn) throws IOException {