From 5f12139816f6c1bc7d625ba8007aedb8f5d04a71 Mon Sep 17 00:00:00 2001 From: Anton Voloshin Date: Thu, 18 Jan 2024 12:45:12 +0300 Subject: [PATCH 1/3] repro for 039_end_of_wal's problem with page end Tags: commitfest_hotfix --- src/test/recovery/t/039_end_of_wal.pl | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/src/test/recovery/t/039_end_of_wal.pl b/src/test/recovery/t/039_end_of_wal.pl index f9acc83c7d0..ecf9b6089de 100644 --- a/src/test/recovery/t/039_end_of_wal.pl +++ b/src/test/recovery/t/039_end_of_wal.pl @@ -36,6 +36,8 @@ my $WAL_SEGMENT_SIZE; my $WAL_BLOCK_SIZE; my $TLI; +my $SizeOfXLogShortPHD = 24; # rounded up to 8 bytes + # Build path of a WAL segment. sub wal_segment_path { @@ -258,9 +260,27 @@ my $prev_lsn; note "Single-page end-of-WAL detection"; ########################################################################### +my $lsn = get_insert_lsn($node); +my $lsn_offset = $lsn % $WAL_BLOCK_SIZE; +my $empty_msg_size = ( ( ($ENV{EMPTY_MSG_SIZE} || 51) + 7) / 8) * 8; +my $commit_msg_size = ( (34 + 7) / 8) * 8; +# empty logical msg and commit message take this many bytes of WAL: +my $empty_msg_overhead = $empty_msg_size + $commit_msg_size; +# cound overhead twice to account for two emit_message calls below: +# we want to hit the page edge after the second call. +my $target_lsn_offset = $WAL_BLOCK_SIZE * 2 - $empty_msg_overhead * 2; +my $msg_size = ($target_lsn_offset - $lsn_offset) % $WAL_BLOCK_SIZE; +# If we happen to switch to the next WAL block mid-message, reduce the message +# by $SizeOfXLogShortPHD (minimal page header) to hit the same target. +if ($lsn_offset + $msg_size >= $WAL_BLOCK_SIZE) { $msg_size -= $SizeOfXLogShortPHD; } +print "QWE0: $lsn WAL_BLOCK_SIZE='$WAL_BLOCK_SIZE', lsn_offset='$lsn_offset' target_lsn_offset='$target_lsn_offset' msg_size='$msg_size'\n"; +emit_message($node, $msg_size); +printf "QWE1: %s - after corrective msg\n", $node->safe_psql('postgres', "SELECT pg_current_wal_lsn()"); # xl_tot_len is 0 (a common case, we hit trailing zeroes). emit_message($node, 0); +printf "QWE2: %s - after zero-length message\n", $node->safe_psql('postgres', "SELECT pg_current_wal_lsn()"); $end_lsn = advance_out_of_record_splitting_zone($node); +printf "QWE3: %s - after advance_out_of_record_splitting_szone()\n", $node->safe_psql('postgres', "SELECT pg_current_wal_lsn()"); $node->stop('immediate'); my $log_size = -s $node->logfile; $node->start; -- 2.43.0