Merge #15209: zmq: log outbound message high water mark when reusing socket

f1dc693 zmq: log outbound message high water mark when reusing socket (fanquake)

Pull request description:

  Running master with `src/bitcoind -zmqpubhashblockhwm=12345 -zmqpubrawtx=tcp://127.0.0.1:28332 -zmqpubhashtxhwm=5000 -zmqpubrawblock=tcp://127.0.0.1:28332 -zmqpubhashtx=tcp://127.0.0.1:28332 -zmqpubhashblock=tcp://127.0.0.1:28332 -debug=zmq`:
  ```
  2019-01-19T14:11:01Z zmq: version 4.3.1
  2019-01-19T14:11:01Z zmq: Initialize notification interface
  2019-01-19T14:11:01Z zmq: Outbound message high water mark for pubhashblock at tcp://127.0.0.1:28332 is 12345
  2019-01-19T14:11:01Z zmq: Notifier pubhashblock ready (address = tcp://127.0.0.1:28332)
  2019-01-19T14:11:01Z zmq: Reusing socket for address tcp://127.0.0.1:28332
  2019-01-19T14:11:01Z zmq: Notifier pubhashtx ready (address = tcp://127.0.0.1:28332)
  2019-01-19T14:11:01Z zmq: Reusing socket for address tcp://127.0.0.1:28332
  2019-01-19T14:11:01Z zmq: Notifier pubrawblock ready (address = tcp://127.0.0.1:28332)
  2019-01-19T14:11:01Z zmq: Reusing socket for address tcp://127.0.0.1:28332
  2019-01-19T14:11:01Z zmq: Notifier pubrawtx ready (address = tcp://127.0.0.1:28332)
  ```

  This PR:
  ```
  2019-01-19T14:06:57Z zmq: version 4.3.1
  2019-01-19T14:06:57Z zmq: Initialize notification interface
  2019-01-19T14:06:57Z zmq: Outbound message high water mark for pubhashblock at tcp://127.0.0.1:28332 is 12345
  2019-01-19T14:06:57Z zmq: Notifier pubhashblock ready (address = tcp://127.0.0.1:28332)
  2019-01-19T14:06:57Z zmq: Reusing socket for address tcp://127.0.0.1:28332
  2019-01-19T14:06:57Z zmq: Outbound message high water mark for pubhashtx at tcp://127.0.0.1:28332 is 5000
  2019-01-19T14:06:57Z zmq: Notifier pubhashtx ready (address = tcp://127.0.0.1:28332)
  2019-01-19T14:06:57Z zmq: Reusing socket for address tcp://127.0.0.1:28332
  2019-01-19T14:06:57Z zmq: Outbound message high water mark for pubrawblock at tcp://127.0.0.1:28332 is 1000
  2019-01-19T14:06:57Z zmq: Notifier pubrawblock ready (address = tcp://127.0.0.1:28332)
  2019-01-19T14:06:57Z zmq: Reusing socket for address tcp://127.0.0.1:28332
  2019-01-19T14:06:57Z zmq: Outbound message high water mark for pubrawtx at tcp://127.0.0.1:28332 is 1000
  2019-01-19T14:06:57Z zmq: Notifier pubrawtx ready (address = tcp://127.0.0.1:28332)
  ```

Tree-SHA512: 6915184d8a0f4764f1cc76dce0099eed411a123d7a4bc8cee1664bb5a233a8119ddd2c78ad980c6e1d9f6dadaba48800ee6bc57de906d4e1b4108df745f1458e

Author: laanwj

src/zmq/zmqpublishnotifier.cpp

@@ -101,6 +101,7 @@ bool CZMQAbstractPublishNotifier::Initialize(void *pcontext)
     else
     {
         LogPrint(BCLog::ZMQ, "zmq: Reusing socket for address %s\n", address);
+        LogPrint(BCLog::ZMQ, "zmq: Outbound message high water mark for %s at %s is %d\n", type, address, outbound_message_high_water_mark);
 
         psocket = i->second->psocket;
         mapPublishNotifiers.insert(std::make_pair(address, this));