Remove redundant 'numPrimaryConns' field.

It was always set to same value as 'numConns'. I guess there was some idea
of also connecting to mirrors with the interconnect, but that hasn't been
used for a long time.

src/backend/cdb/motion/ic_common.c

@@ -612,7 +612,7 @@ TeardownInterconnect(ChunkTransportState *transportStates,
  *
  *	 motNodeID - motion node ID for this ChunkTransportState.
  *
- *	 numPrimaryConns  - number of primary connections for this motion node.
+ *	 numConns  - number of primary connections for this motion node.
  *               All are incoming if this is a receiving motion node.
  *               All are outgoing if this is a sending motion node.
  *
@@ -625,7 +625,7 @@ ChunkTransportStateEntry *
 createChunkTransportState(ChunkTransportState *transportStates,
 						  Slice *sendSlice,
 						  Slice *recvSlice,
-						  int numPrimaryConns)
+						  int numConns)
 {
 	ChunkTransportStateEntry *pEntry;
 	int			motNodeID;
@@ -667,8 +667,7 @@ createChunkTransportState(ChunkTransportState *transportStates,
 	pEntry->valid = true;
 
 	pEntry->motNodeId = motNodeID;
-	pEntry->numConns = numPrimaryConns;
-	pEntry->numPrimaryConns = numPrimaryConns;
+	pEntry->numConns = numConns;
 	pEntry->scanStart = 0;
 	pEntry->sendSlice = sendSlice;
 	pEntry->recvSlice = recvSlice;

src/backend/cdb/motion/ic_tcp.c

@@ -122,7 +122,7 @@ getMotionConn(ChunkTransportStateEntry *pEntry, int iConn)
 {
 	Assert(pEntry);
 	Assert(pEntry->conns);
-	Assert(iConn < pEntry->numConns + pEntry->numPrimaryConns);
+	Assert(iConn < pEntry->numConns);
 
 	return pEntry->conns + iConn;
 }
@@ -592,8 +592,7 @@ startOutgoingConnections(ChunkTransportState *transportStates,
 
 	/*
 	 * Setup a MotionConn entry for each of our outbound connections. Request
-	 * a connection to each receiving backend's listening port. NB: Some
-	 * mirrors could be down & have no CdbProcess entry.
+	 * a connection to each receiving backend's listening port.
 	 */
 	conn = pEntry->conns;
 
@@ -2209,9 +2208,8 @@ dumpEntryConnections(int elevel, ChunkTransportStateEntry *pEntry)
 				 pEntry->motNodeId, i);
 		else
 			elog(elevel, "... motNodeId=%d conns[%d]:  "
-				 "%s%d pid=%d sockfd=%d remote=%s local=%s",
+				 "%d pid=%d sockfd=%d remote=%s local=%s",
 				 pEntry->motNodeId, i,
-				 (i < pEntry->numPrimaryConns) ? "seg" : "mir",
 				 conn->remoteContentId,
 				 conn->cdbProc ? conn->cdbProc->pid : 0,
 				 conn->sockfd,

src/backend/cdb/motion/ic_udpifc.c

@@ -6742,10 +6742,10 @@ dumpConnections(ChunkTransportStateEntry *pEntry, const char *fname)
 
 	FILE	   *ofile = fopen(fname, "w+");
 
-	fprintf(ofile, "Entry connections: conn num %d \n", pEntry->numPrimaryConns);
+	fprintf(ofile, "Entry connections: conn num %d \n", pEntry->numConns);
 	fprintf(ofile, "==================================\n");
 
-	for (i = 0; i < pEntry->numPrimaryConns; i++)
+	for (i = 0; i < pEntry->numConns; i++)
 	{
 		conn = &pEntry->conns[i];
 

src/include/cdb/cdbinterconnect.h

@@ -317,10 +317,9 @@ typedef struct ChunkTransportStateEntry
 	int         motNodeId;
 	bool		valid;
 
-	/* Connection array: first the primaries, then the mirrors (if needed) */
+	/* Connection array */
     MotionConn *conns;
-	int			numConns;               /* all, including mirrors if present */
-    int         numPrimaryConns;        /* does not include mirrors */
+	int			numConns;
 
 	/*
 	 * used for receiving. to select() from a set of interesting MotionConns

src/include/cdb/ml_ipc.h

@@ -299,7 +299,7 @@ extern void putTransportDirectBuffer(ChunkTransportState *transportStates,
 extern ChunkTransportStateEntry *createChunkTransportState(ChunkTransportState *transportStates,
 														   Slice *sendSlice,
 														   Slice *recvSlice,
-														   int numPrimaryConns);
+														   int numConns);
 
 extern ChunkTransportStateEntry *removeChunkTransportState(ChunkTransportState *transportStates,
 														   int16 motNodeID);