@Override
          public void run2() {
            try {
              if (!pr.isLocallyDestroyed && !pr.isClosed && !pr.isDestroyed()) {
                dm.putOutgoing(delayedInstance);
              }
            } catch (CancelException cce) {
              // cache is closed - can't send the message
            } finally {
              tm.cancel();
            }
          }
Send a sanity check message and schedule a timer to send another one in
gemfire.PRSanityCheckInterval (default 5000) milliseconds. This can be enabled with
gemfire.PRSanityCheckEnabled=true.
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/PRSanityCheckMessage.java