diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
new file mode 100644
index e42b828..e7b56b6
*** a/src/backend/access/transam/xlog.c
--- b/src/backend/access/transam/xlog.c
*************** retry:
*** 11648,11654 ****
  	}
  
  	pgstat_report_wait_start(WAIT_EVENT_WAL_READ);
! 	if (read(readFile, readBuf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
  	{
  		char		fname[MAXFNAMELEN];
  
--- 11648,11654 ----
  	}
  
  	pgstat_report_wait_start(WAIT_EVENT_WAL_READ);
! 	if (read(readFile, readBuf, readLen) != readLen)
  	{
  		char		fname[MAXFNAMELEN];
  
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
new file mode 100644
index 3a86f34..12d38f0
*** a/src/backend/access/transam/xlogreader.c
--- b/src/backend/access/transam/xlogreader.c
*************** XLogReadRecord(XLogReaderState *state, X
*** 354,359 ****
--- 354,365 ----
  		char	   *buffer;
  		uint32		gotlen;
  
+ 		/*
+ 		 * Since we're going to copy the rest of the current page, the whole
+ 		 * page should be in readBuf.
+ 		 */
+ 		Assert(readOff == XLOG_BLCKSZ);
+ 
  		/* Copy the first fragment of the record from the first page. */
  		memcpy(state->readRecordBuf,
  			   state->readBuf + RecPtr % XLOG_BLCKSZ, len);
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
new file mode 100644
index 130ecd5..9f2d40b
*** a/src/backend/replication/walsender.c
--- b/src/backend/replication/walsender.c
***************
*** 103,109 ****
   * because signals are checked only between messages.  128kB (with
   * default 8k blocks) seems like a reasonable guess for now.
   */
! #define MAX_SEND_SIZE (XLOG_BLCKSZ * 16)
  
  /* Array of WalSnds in shared memory */
  WalSndCtlData *WalSndCtl = NULL;
--- 103,109 ----
   * because signals are checked only between messages.  128kB (with
   * default 8k blocks) seems like a reasonable guess for now.
   */
! #define MAX_SEND_SIZE (XLOG_BLCKSZ / 2)
  
  /* Array of WalSnds in shared memory */
  WalSndCtlData *WalSndCtl = NULL;
*************** XLogSendPhysical(void)
*** 2688,2694 ****
  	else
  	{
  		/* round down to page boundary. */
! 		endptr -= (endptr % XLOG_BLCKSZ);
  		WalSndCaughtUp = false;
  	}
  
--- 2688,2694 ----
  	else
  	{
  		/* round down to page boundary. */
! 		//endptr -= (endptr % XLOG_BLCKSZ);
  		WalSndCaughtUp = false;
  	}