Fixed issue with producer flow control in a cluster.

Producer flow control uses a Timer and other clock-based calculations to send flow control commands.
These commands are not predictably ordered from the clusters point of view.

Added getClusterOrderProxy() to SessionState. In a cluster it returns
a proxy that defers sending a command to the client until it is
multicast to the cluster.  In a stand alone broker it is just the
normal proxy. Updated producer flow control to use this proxy.

Cluster flow control is turned off in shadow connections. Only the
directly connected node does flow control calculations and multicasts
the commands to send. All nodes sending of the commands thru SessionState
to ensure consistent session state (e.g. command numbering.)


git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk/qpid@747528 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 11 insertions, 6 deletions

diff --git a/cpp/src/qpid/broker/SessionState.cpp b/cpp/src/qpid/broker/SessionState.cpp
index dffc7cf6af..b64fc20787 100644
--- a/cpp/src/qpid/broker/SessionState.cpp
+++ b/cpp/src/qpid/broker/SessionState.cpp
@@ -66,7 +66,7 @@ SessionState::SessionState(
     uint32_t maxRate = broker.getOptions().maxSessionRate;
     if (maxRate) {
         if (handler->getConnection().getClientThrottling()) {
-            rateFlowcontrol = new RateFlowcontrol(maxRate);
+            rateFlowcontrol.reset(new RateFlowcontrol(maxRate));
         } else {
             QPID_LOG(warning, getId() << ": Unable to flow control client - client doesn't support");
         }
@@ -210,7 +210,6 @@ struct ScheduledCreditTask : public TimerTask {
     {}
 
     void fire() {
-        QPID_LOG(critical, "ScheduledCreditTask fired"); // FIXME aconway 2009-02-23: REMOVE
         // This is the best we can currently do to avoid a destruction/fire race
         if (!isCancelled()) {
             if ( !sessionState.processSendCredit(0) ) {
@@ -275,7 +274,8 @@ bool SessionState::processSendCredit(uint32_t msgs)
     if ( msgs > 0 && rateFlowcontrol->flowStopped() ) {
         QPID_LOG(warning, getId() << ": producer throttling violation");
         // TODO: Probably do message.stop("") first time then disconnect
-        getProxy().getMessage().stop("");
+        // See comment on getClusterOrderProxy() in .h file
+        getClusterOrderProxy().getMessage().stop("");
         return true;
     }
     AbsTime now = AbsTime::now();
@@ -283,7 +283,7 @@ bool SessionState::processSendCredit(uint32_t msgs)
     if (mgmtObject) mgmtObject->dec_clientCredit(msgs);
     if ( sendCredit>0 ) {
         QPID_LOG(debug, getId() << ": send producer credit " << sendCredit);
-        getProxy().getMessage().flow("", 0, sendCredit);
+        getClusterOrderProxy().getMessage().flow("", 0, sendCredit);
         rateFlowcontrol->sentCredit(now, sendCredit);
         if (mgmtObject) mgmtObject->inc_clientCredit(sendCredit);
         return true;
@@ -364,8 +364,9 @@ void SessionState::readyToSend() {
         // Issue initial credit - use a heuristic here issue min of 300 messages or 1 secs worth
         uint32_t credit = std::min(rateFlowcontrol->getRate(), 300U);
         QPID_LOG(debug, getId() << ": Issuing producer message credit " << credit);
-        getProxy().getMessage().setFlowMode("", 0);
-        getProxy().getMessage().flow("", 0, credit);
+        // See comment on getClusterOrderProxy() in .h file
+        getClusterOrderProxy().getMessage().setFlowMode("", 0);
+        getClusterOrderProxy().getMessage().flow("", 0, credit);
         rateFlowcontrol->sentCredit(AbsTime::now(), credit);
         if (mgmtObject) mgmtObject->inc_clientCredit(credit);
     }
@@ -373,4 +374,8 @@ void SessionState::readyToSend() {
 
 Broker& SessionState::getBroker() { return broker; }
 
+framing::AMQP_ClientProxy& SessionState::getClusterOrderProxy() {
+    return handler->getClusterOrderProxy();
+}
+
 }} // namespace qpid::broker