Fix shard hash caclulation

neondatabase · Nov 29, 2023 · a6e6cb0 · a6e6cb0
1 parent d858557
commit a6e6cb0
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Showing 2 changed files with 15 additions and 6 deletions.
diff --git a/pgxn/neon/libpagestore.c b/pgxn/neon/libpagestore.c
@@ -213,14 +213,14 @@ get_shard_number(BufferTag* tag)
 
 #if PG_MAJORVERSION_NUM < 16
 	hash = murmurhash32(tag->rnode.spcNode);
-	hash_combine(hash, murmurhash32(tag->rnode.dbNode));
-	hash_combine(hash, murmurhash32(tag->rnode.relNode));
-	hash_combine(hash, murmurhash32(tag->blockNum/(MB/BLCKSZ)/stripe_size));
+	hash = hash_combine(hash, murmurhash32(tag->rnode.dbNode));
+	hash = hash_combine(hash, murmurhash32(tag->rnode.relNode));
+	hash = hash_combine(hash, murmurhash32(tag->blockNum/(MB/BLCKSZ)/stripe_size));
 #else
 	hash = murmurhash32(tag->spcOid);
-	hash_combine(hash, murmurhash32(tag->dbOid));
-	hash_combine(hash, murmurhash32(tag->relNumber));
-	hash_combine(hash, murmurhash32(tag->blockNum/(MB/BLCKSZ)/stripe_size));
+	hash = hash_combine(hash, murmurhash32(tag->dbOid));
+	hash = hash_combine(hash, murmurhash32(tag->relNumber));
+	hash = hash_combine(hash, murmurhash32(tag->blockNum/(MB/BLCKSZ)/stripe_size));
 #endif
 
 	return hash % n_shards;

diff --git a/pgxn/neon/pagestore_smgr.c b/pgxn/neon/pagestore_smgr.c
@@ -919,6 +919,15 @@ page_server_request(void const *req)
 	}
 	shard_no = get_shard_number(&tag);
 
+	/*
+	 * TODO: temporary workarround - we stream all WAL only to shard 0 so metadata and forks other than main
+	 * should be requested from shard 0. We still need to call get_shard_no() to check if shard map is up-to-date
+	 */
+	if (((NeonRequest *) req)->tag != T_NeonGetPageRequest || ((NeonGetPageRequest *) req)->forknum != MAIN_FORKNUM)
+	{
+		shard_no = 0;
+	}
+
 	do {
 		while (!page_server->send(shard_no, (NeonRequest *) req) || !page_server->flush(shard_no));
 		MyPState->ring_flush = MyPState->ring_unused;