From: Pavan Deolasee <pavan.deolasee@gmail.com>
Date: Mon, 3 Apr 2017 17:06:19 +0000 (+0530)
Subject: Try to validate the combiner only when a RESPONSE_COPY is received during
X-Git-Tag: XL_10_R1BETA1~325
X-Git-Url: http://git.postgresql.org/gitweb/-?a=commitdiff_plain;h=275ef1024983bd39dc07a6d73944ef7a8b9a9594;p=postgres-xl.git

Try to validate the combiner only when a RESPONSE_COPY is received during
running COPY protocol.

We sometimes do see a 'M' message (command ID received from the remote node)
from the datanode and that breaks the combiner validation message. So we only
do that if we received a RESPONSE_COPY message during COPY IN protocol.
---

diff --git a/src/backend/pgxc/pool/execRemote.c b/src/backend/pgxc/pool/execRemote.c
index 02bfb6c0d3..9cf3541ac7 100644
--- a/src/backend/pgxc/pool/execRemote.c
+++ b/src/backend/pgxc/pool/execRemote.c
@@ -2900,8 +2900,22 @@ DataNodeCopyIn(char *data_row, int len,
 					 * Make sure there are zeroes in unused fields
 					 */
 					memset(&combiner, 0, sizeof(ScanState));
-					handle_response(handle, &combiner);
-					if (!ValidateAndCloseCombiner(&combiner))
+
+					/*
+					 * Validate the combiner but only if we see a proper
+					 * resposne for our COPY message. The problem is that
+					 * sometimes we might receive async messages such as
+					 * 'M' which is used to send back command ID generated and
+					 * consumed by the datanode. While the message gets handled
+					 * in handle_response(), we don't want to declare receipt
+					 * of an invalid message below.
+					 *
+					 * If there is an actual error of some sort then the
+					 * connection state is will be set appropriately and we
+					 * shall catch that subsequently.
+					 */
+					if (handle_response(handle, &combiner) == RESPONSE_COPY &&
+						!ValidateAndCloseCombiner(&combiner))
 						return EOF;
 				}