add 00002_log_and_exception_messages_formatting back

tests/queries/0_stateless/00002_log_and_exception_messages_formatting.reference

@@ -0,0 +1,15 @@
+runtime messages	0.001
+runtime exceptions	0.05
+messages shorter than 10	10
+messages shorter than 16	40
+exceptions shorter than 30	125
+noisy messages	0.3
+noisy Trace messages	0.16
+noisy Debug messages	0.09
+noisy Info messages	0.05
+noisy Warning messages	0.01
+noisy Error messages	0.02
+no Fatal messages	0
+number of too noisy messages	3
+number of noisy messages	10
+incorrect patterns	15

tests/queries/0_stateless/00002_log_and_exception_messages_formatting.sql

@@ -0,0 +1,64 @@
+-- Tags: no-parallel, no-fasttest
+-- no-parallel because we want to run this test when most of the other tests already passed
+
+-- If this test fails, see the "Top patterns of log messages" diagnostics in the end of run.log
+
+system flush logs;
+drop table if exists logs;
+create view logs as select * from system.text_log where now() - toIntervalMinute(120) < event_time;
+
+-- Check that we don't have too many messages formatted with fmt::runtime or strings concatenation.
+-- 0.001 threshold should be always enough, the value was about 0.00025
+select 'runtime messages', max2(coalesce(sum(length(message_format_string) = 0) / countOrNull(), 0), 0.001) from logs;
+
+-- Check the same for exceptions. The value was 0.03
+select 'runtime exceptions', max2(coalesce(sum(length(message_format_string) = 0) / countOrNull(), 0), 0.05) from logs where message like '%DB::Exception%';
+
+-- Check that we don't have too many short meaningless message patterns.
+select 'messages shorter than 10', max2(countDistinctOrDefault(message_format_string), 10) from logs where length(message_format_string) < 10;
+
+-- Same as above. Feel free to update the threshold or remove this query if really necessary
+select 'messages shorter than 16', max2(countDistinctOrDefault(message_format_string), 40) from logs where length(message_format_string) < 16;
+
+-- Same as above, but exceptions must be more informative. Feel free to update the threshold or remove this query if really necessary
+select 'exceptions shorter than 30', max2(countDistinctOrDefault(message_format_string), 125) from logs where length(message_format_string) < 30 and message ilike '%DB::Exception%';
+
+
+-- Avoid too noisy messages: top 1 message frequency must be less than 30%. We should reduce the threshold
+select 'noisy messages', max2((select count() from logs group by message_format_string order by count() desc limit 1) / (select count() from logs), 0.30);
+
+-- Same as above, but excluding Test level (actually finds top 1 Trace message)
+with ('Access granted: {}{}', '{} -> {}') as frequent_in_tests
+select 'noisy Trace messages', max2((select count() from logs where level!='Test' and message_format_string not in frequent_in_tests
+    group by message_format_string order by count() desc limit 1) / (select count() from logs), 0.16);
+
+-- Same as above for Debug
+select 'noisy Debug messages', max2((select count() from logs where level <= 'Debug' group by message_format_string order by count() desc limit 1) / (select count() from logs), 0.09);
+
+-- Same as above for Info
+select 'noisy Info messages', max2((select count() from logs where level <= 'Information' group by message_format_string order by count() desc limit 1) / (select count() from logs), 0.05);
+
+-- Same as above for Warning
+with ('Not enabled four letter command {}') as frequent_in_tests
+select 'noisy Warning messages', max2((select countOrDefault() from logs where level = 'Warning' and message_format_string not in frequent_in_tests
+    group by message_format_string order by count() desc limit 1) / (select count() from logs), 0.01);
+
+-- Same as above for Error
+select 'noisy Error messages', max2((select countOrDefault() from logs where level = 'Error' group by message_format_string order by count() desc limit 1) / (select count() from logs), 0.02);
+
+select 'no Fatal messages', count() from logs where level = 'Fatal';
+
+
+-- Avoid too noisy messages: limit the number of messages with high frequency
+select 'number of too noisy messages', max2(count(), 3) from (select count() / (select count() from logs) as freq, message_format_string from logs group by message_format_string having freq > 0.10);
+select 'number of noisy messages', max2(count(), 10) from (select count() / (select count() from logs) as freq, message_format_string from logs group by message_format_string having freq > 0.05);
+
+-- Each message matches its pattern (returns 0 rows)
+-- FIXME maybe we should make it stricter ('Code:%Exception: '||s||'%'), but it's not easy because of addMessage
+select 'incorrect patterns', max2(countDistinct(message_format_string), 15) from (
+    select message_format_string, any(message) as any_message from logs
+    where message not like (replaceRegexpAll(message_format_string, '{[:.0-9dfx]*}', '%') as s)
+    and message not like ('%Exception: '||s||'%') group by message_format_string
+) where any_message not like '%Poco::Exception%';
+
+drop table logs;