MDEV-34504 PURGE BINARY LOGS not working anymore

PURGE BINARY LOGS did not always purge binary logs. This commit fixes
some of the issues and adds notifications if a binary log cannot be
purged.

User visible changes:
- 'PURGE BINARY LOG TO log_name' and 'PURGE BINARY LOGS BEFORE date'
  worked differently. 'TO' ignored 'slave_connections_needed_for_purge'
  while 'BEFORE' did not. Now both versions ignores the
  'slave_connections_needed_for_purge variable'.
- 'PURGE BINARY LOG..' commands now returns 'note' if a binary log cannot
   be deleted like
   Note 1375 Binary log 'master-bin.000004' is not purged because it is
             the current active binlog
- Automatic binary log purges, based on date or size, will write a
  note to the error log if a binary log matching the size or date
  cannot yet be deleted.
- If 'slave_connections_needed_for_purge' is set from a config or
  command line, it is set to 0 if Galera is enabled and 1 otherwise
  (old default). This ensures that automatic binary log purge works
  with Galera as before the addition of
  'slave_connections_needed_for_purge'.
  If the variable is changed to 0, a warning will be printed to the error
  log.

Code changes:
- Added THD argument to several purge_logs related functions that needed
  THD.
- Added 'interactive' options to purge_logs functions. This allowed
  me to remove testing of sql_command == SQLCOM_PURGE.
- Changed purge_logs_before_date() to first check if log is applicable
  before calling can_purge_logs(). This ensures we do not get a
  notification for logs that does not match the remove criteria.
- MYSQL_BIN_LOG::can_purge_log() will write notifications to the user
  or error log if a log cannot yet be removed.
- log_in_use() will return reason why a binary log cannot be removed.

Changes to keep code consistent:
- Moved checking of binlog_format for Galera to be after Galera is
  initialized (The old check never worked). If Galera is enabled
  we now change the binlog_format to ROW, with a warning, instead of
  aborting the server. If this change happens a warning will be printed to
  the error log.
- Print a warning if Galera or FLASHBACK changes the binlog_format
  to ROW. Before it was done silently.

Reviewed by: Sergei Golubchik <serg@mariadb.com>,
             Kristian Nielsen <knielsen@knielsen-hq.org>

Author: montywi

mysql-test/include/wait_for_purge.inc

@@ -20,14 +20,16 @@
 #
 # SIDE EFFECTS:
 #
-#    Disables --query_log while running, enables it afterwards.
+#    Disables --query_log and warnings while running, enables them afterwards.
 
 --echo include/wait_for_purge.inc "$purge_binlogs_to"
 
 let $_wait_count= 300;
 let $_done= 0;
 
 --disable_query_log
+--disable_warnings
+
 while ($_wait_count)
 {
   dec $_wait_count;
@@ -50,4 +52,5 @@ if (!$_done)
   eval SHOW BINARY LOGS;
   --die ERROR: failed while waiting for binlog purge to $purge_binlogs_to
 }
+--enable_warnings
 --enable_query_log

mysql-test/main/mysqld--help.result

@@ -1308,6 +1308,7 @@ The following specify which files/extra groups are read (specified before remain
  Minimum number of connected slaves required for automatic
  binary log purge with max_binlog_total_size,
  binlog_expire_logs_seconds or binlog_expire_logs_days.
+ Default is 0 when Galera is enabled and 1 otherwise.
  --slave-ddl-exec-mode=name 
  How replication events should be executed. Legal values
  are STRICT and IDEMPOTENT (default). In IDEMPOTENT mode,

mysql-test/suite/binlog/r/binlog_flush_binlogs_delete_domain.result

@@ -49,6 +49,9 @@ ERROR HY000: Could not delete gtid domain. Reason: binlog files may contain gtid
 MDEV-31140: Missing error from DELETE_DOMAIN_ID when gtid_binlog_state partially matches GTID_LIST.
 FLUSH BINARY LOGS;
 PURGE BINARY LOGS TO 'master-bin.000005';
+show binary logs;
+Log_name	File_size
+master-bin.000005	#
 SET @@SESSION.gtid_domain_id=8;
 SET @@SESSION.server_id=10*8 + 1;
 INSERT INTO t SELECT 1+MAX(a) FROM t;

mysql-test/suite/binlog/r/binlog_index.result

@@ -30,6 +30,7 @@ flush logs;
 flush logs;
 *** must be a warning master-bin.000001 was not found ***
 Warnings:
+Note	1375	Binary log 'master-bin.000004' is not purged because it is the current active binlog
 Warning	1612	Being purged log master-bin.000001 was not found
 *** must show one record, of the active binlog, left in the index file after PURGE ***
 show binary logs;

mysql-test/suite/binlog/r/binlog_xa_recover.result

@@ -89,6 +89,8 @@ master-bin.000006	#	Format_desc	#	#	SERVER_VERSION, BINLOG_VERSION
 master-bin.000006	#	Gtid_list	#	#	[#-#-#]
 master-bin.000006	#	Binlog_checkpoint	#	#	master-bin.000004
 PURGE BINARY LOGS TO "master-bin.000006";
+Warnings:
+Note	1375	Binary log 'master-bin.000004' is not purged because it may be needed for crash recovery (XID)
 show binary logs;
 Log_name	File_size
 master-bin.000004	#

mysql-test/suite/binlog/t/binlog_flush_binlogs_delete_domain.test

@@ -91,6 +91,7 @@ while ($domain_cnt)
 FLUSH BINARY LOGS;
 --let $purge_to_binlog= query_get_value(SHOW MASTER STATUS, File, 1)
 --eval PURGE BINARY LOGS TO '$purge_to_binlog'
+--source include/show_binary_logs.inc
 --eval SET @@SESSION.gtid_domain_id=$err_domain_id
 --eval SET @@SESSION.server_id=10*$err_domain_id + $err_server_id
 eval INSERT INTO t SELECT 1+MAX(a) FROM t;

mysql-test/suite/binlog_encryption/binlog_index.result

@@ -30,6 +30,7 @@ flush logs;
 flush logs;
 *** must be a warning master-bin.000001 was not found ***
 Warnings:
+Note	1375	Binary log 'master-bin.000004' is not purged because it is the current active binlog
 Warning	1612	Being purged log master-bin.000001 was not found
 *** must show one record, of the active binlog, left in the index file after PURGE ***
 show binary logs;

mysql-test/suite/binlog_encryption/binlog_xa_recover.result

@@ -93,6 +93,8 @@ master-bin.000006	#	Start_encryption	#	#
 master-bin.000006	#	Gtid_list	#	#	[#-#-#]
 master-bin.000006	#	Binlog_checkpoint	#	#	master-bin.000004
 PURGE BINARY LOGS TO "master-bin.000006";
+Warnings:
+Note	1375	Binary log 'master-bin.000004' is not purged because it may be needed for crash recovery (XID)
 show binary logs;
 Log_name	File_size
 master-bin.000004	#

mysql-test/suite/compat/oracle/r/binlog_ptr_mysqlbinlog.result

@@ -1,3 +1,4 @@
+call mtr.add_suppression("Binlog_format changed to.*flashback");
 SET @@SQL_MODE = 'ORACLE';
 ##########################################################################
 #      Test verifies Gtid_log_event/Xid_log_event specific print         #

mysql-test/suite/compat/oracle/t/binlog_ptr_mysqlbinlog.test

@@ -18,6 +18,8 @@
 --source include/have_log_bin.inc
 --source include/have_innodb.inc
 
+call mtr.add_suppression("Binlog_format changed to.*flashback");
+
 let $MYSQLD_DATADIR= `select @@datadir`;
 SET @@SQL_MODE = 'ORACLE';