From a5e06a3ea7248639079e84627fa8e74b49f99337 Mon Sep 17 00:00:00 2001
From: Konstantin Knizhnik <knizhnik@neon.tech>
Date: Tue, 23 Jan 2024 14:26:22 +0200
Subject: [PATCH] Use GetXLogReplayRecPtr only for replicas

---
 pgxn/neon/pagestore_smgr.c                  | 14 +++++++-------
 test_runner/regress/test_replication_lag.py |  2 --
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/pgxn/neon/pagestore_smgr.c b/pgxn/neon/pagestore_smgr.c
index 751d2eb039..592107a619 100644
--- a/pgxn/neon/pagestore_smgr.c
+++ b/pgxn/neon/pagestore_smgr.c
@@ -113,9 +113,9 @@ static bool (*old_redo_read_buffer_filter) (XLogReaderState *record, uint8 block
 #define MAX_LSN ((XLogRecPtr)~0)
 
 static XLogRecPtr
-neon_get_horizon(bool latest)
+neon_get_horizon(XLogRecPtr lsn, bool latest)
 {
-	return latest ? MAX_LSN : GetXLogReplayRecPtr(NULL);
+	return latest ? MAX_LSN : RecoveryInProgress() ? GetXLogReplayRecPtr(NULL) : lsn;
 }
 
 /*
@@ -735,7 +735,7 @@ prefetch_do_request(PrefetchRequest *slot, bool *force_latest, XLogRecPtr *force
 		prefetch_lsn = Max(prefetch_lsn, lsn);
 		slot->effective_request_lsn = prefetch_lsn;
 	}
-	request.req.horizon = neon_get_horizon(latest);
+	request.req.horizon = neon_get_horizon(request.req.lsn, latest);
 
 	Assert(slot->response == NULL);
 	Assert(slot->my_ring_index == MyPState->ring_unused);
@@ -1664,7 +1664,7 @@ neon_exists(SMgrRelation reln, ForkNumber forkNum)
 	{
 		NeonExistsRequest request = {
 			.req.tag = T_NeonExistsRequest,
-			.req.horizon = neon_get_horizon(latest),
+			.req.horizon = neon_get_horizon(request_lsn, latest),
 			.req.lsn = request_lsn,
 			.rinfo = InfoFromSMgrRel(reln),
 		.forknum = forkNum};
@@ -2473,7 +2473,7 @@ neon_nblocks(SMgrRelation reln, ForkNumber forknum)
 	{
 		NeonNblocksRequest request = {
 			.req.tag = T_NeonNblocksRequest,
-			.req.horizon = neon_get_horizon(latest),
+			.req.horizon = neon_get_horizon(request_lsn, latest),
 			.req.lsn = request_lsn,
 			.rinfo = InfoFromSMgrRel(reln),
 			.forknum = forknum,
@@ -2530,7 +2530,7 @@ neon_dbsize(Oid dbNode)
 	{
 		NeonDbSizeRequest request = {
 			.req.tag = T_NeonDbSizeRequest,
-			.req.horizon = neon_get_horizon(latest),
+			.req.horizon = neon_get_horizon(request_lsn, latest),
 			.req.lsn = request_lsn,
 			.dbNode = dbNode,
 		};
@@ -2979,7 +2979,7 @@ neon_extend_rel_size(NRelFileInfo rinfo, ForkNumber forknum, BlockNumber blkno,
 		NeonNblocksRequest request = {
 			.req = (NeonRequest) {
 				.lsn = end_recptr,
-				.horizon = neon_get_horizon(false),
+				.horizon = neon_get_horizon(end_recptr, false),
 				.tag = T_NeonNblocksRequest,
 			},
 			.rinfo = rinfo,
diff --git a/test_runner/regress/test_replication_lag.py b/test_runner/regress/test_replication_lag.py
index e39c8a1007..2b638eb017 100644
--- a/test_runner/regress/test_replication_lag.py
+++ b/test_runner/regress/test_replication_lag.py
@@ -1,5 +1,4 @@
 import threading
-import time
 
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnv, PgBin
@@ -34,7 +33,6 @@ def test_replication_lag(neon_simple_env: NeonEnv, pg_bin: PgBin):
         t.start()
 
         with env.endpoints.new_replica_start(origin=primary, endpoint_id="secondary") as secondary:
-            time.sleep(10)
             for _ in range(1, n_iterations):
                 primary_lsn = primary.safe_psql_scalar(
                     "SELECT pg_current_wal_flush_lsn()::text", log_query=False