On Sat, Jan 27, 2024 at 11:00:01AM +0300, Alexander Lakhin wrote: > 24.01.2024 20:46, Robert Haas wrote: >> This is weird. There's a little more detail in the log file, >> regress_log_002_blocks, e.g. from the first failure you linked: >> >> [11:18:20.683](96.787s) # before insert, summarized TLI 1 through 0/14E09D0 >> [11:18:21.188](0.505s) # after insert, summarized TLI 1 through 0/14E0D08 >> [11:18:21.326](0.138s) # examining summary for TLI 1 from 0/14E0D08 to >> 0/155BAF0 >> # 1 >> ... >> [11:18:21.349](0.000s) # got: 'pg_walsummary: error: could >> not open file >> "/home/nm/farm/gcc64/HEAD/pgsql.build/src/bin/pg_walsummary/tmp_check/t_002_blocks_node1_data/pgdata/pg_wal/summaries/0000000100000000014E0D0800000000155BAF0 >> # 1.summary": No such file or directory' >> >> The "examining summary" line is generated based on the output of >> pg_available_wal_summaries(). The way that works is that the server >> calls readdir(), disassembles the filename into a TLI and two LSNs, >> and returns the result. > > I'm discouraged by "\n1" in the file name and in the > "examining summary..." message. > regress_log_002_blocks from the following successful test run on the same > sungazer node contains: > [15:21:58.924](0.106s) # examining summary for TLI 1 from 0/155BAE0 to > 0/155E750 > [15:21:58.925](0.001s) ok 1 - WAL summary file exists
Ah, I think this query: SELECT tli, start_lsn, end_lsn from pg_available_wal_summaries() WHERE tli = $summarized_tli AND end_lsn > '$summarized_lsn' is returning more than one row in some cases. I attached a quick sketch of an easy way to reproduce the issue as well as one way to fix it. -- Nathan Bossart Amazon Web Services: https://aws.amazon.com
diff --git a/src/bin/pg_walsummary/t/002_blocks.pl b/src/bin/pg_walsummary/t/002_blocks.pl index 40908da8cb..5609b1bd14 100644 --- a/src/bin/pg_walsummary/t/002_blocks.pl +++ b/src/bin/pg_walsummary/t/002_blocks.pl @@ -64,10 +64,16 @@ SELECT EXISTS ( ) EOM +$node1->safe_psql('postgres', <<EOM); +UPDATE mytable SET b = 'abefghijklmnopqrstuvwxyz' WHERE a = 2; +CHECKPOINT; +EOM +$node1->safe_psql('postgres', 'SELECT pg_sleep(1);'); + # Figure out the exact details for the new summary file. my $details = $node1->safe_psql('postgres', <<EOM); SELECT tli, start_lsn, end_lsn from pg_available_wal_summaries() - WHERE tli = $summarized_tli AND end_lsn > '$summarized_lsn' + WHERE tli = $summarized_tli AND end_lsn > '$summarized_lsn' ORDER BY end_lsn LIMIT 1 EOM my ($tli, $start_lsn, $end_lsn) = split(/\|/, $details); note("examining summary for TLI $tli from $start_lsn to $end_lsn");