Bug #87295 Test group_replication.gr_single_primary_majority_loss_1 produces warnings

Description:
Test group_replication.gr_single_primary_majority_loss_1 produces warnings consistently. For some reason they are reported at the end of MTR run, but intermittently the same warnings are reported during the testcase warning check, failing the testcase.

$ ./mtr --debug-server --suite=group_replication gr_single_primary_majority_loss_1 --big-test
...
group_replication.gr_single_primary_majority_loss_1 [ pass ]  68037
--------------------------------------------------------------------------
The servers were restarted 0 times
Spent 68.037 of 104 seconds executing testcases
mysql-test-run: WARNING: Got errors/warnings while running tests, please examine '/Users/laurynas/percona/obj-mysql-8.0.2-asan-debug-openssl/mysql-test/var/log/warnings' for details.
...
$ cat var/log/warnings 
group_replication.gr_single_primary_majority_loss_1
line
2017-08-03T08:11:10.013717Z 0 [Warning] Plugin group_replication reported: 'The member lost contact with a majority of the members in the group. Until the network is restored transactions will block. As the value of group_replication_unreachable_majority_timeout is 0 the plugin will wait indefinitely for the network to be restored.'
2017-08-03T08:11:12.020926Z 0 [Warning] Plugin group_replication reported: 'The member resumed contact with a majority of the members in the group. Regular operation is re-established.'
^ Found warnings in /Users/laurynas/percona/obj-mysql-8.0.2-asan-debug-openssl/mysql-test/var/log/mysqld.1.err
ok
 

How to repeat:
Mac, CMake options for these particular runs are -DBUILD_CONFIG=mysql_release -DWITH_DEBUG=ON -DWITH_ASAN=ON -DWITH_BOOST=... -DWITH_OPENSSL=/path/to/homebrew/OpenSSL -DWITH_ZLIB=system -DWITH_LZ4=system -DENABLE_DOWNLOADS=ON

MTR command given above

Hello Laurynas,

Thank you for the report.

Thanks,
Umesh

The same happens with group_replication.gr_recovery_channel. Piggybacking here instead of filing a new bug.

$ ./mtr --debug-server gr_recovery_channel --big-test
...
group_replication.gr_recovery_channel    [ pass ]  73377
--------------------------------------------------------------------------
The servers were restarted 0 times
Spent 73.377 of 106 seconds executing testcases
mysql-test-run: WARNING: Got errors/warnings while running tests, please examine '/Users/laurynas/percona/obj-mysql-8.0.2-pp-asan-debug-openssl/mysql-test/var/log/warnings' for details.

$ cat var/log/warnings 
group_replication.gr_recovery_channel
line
2017-08-03T13:22:57.628067Z 0 [Warning] Plugin group_replication reported: 'The member lost contact with a majority of the members in the group. Until the network is restored transactions will block. As the value of group_replication_unreachable_majority_timeout is 0 the plugin will wait indefinitely for the network to be restored.'
2017-08-03T13:22:58.628466Z 0 [Warning] Plugin group_replication reported: 'The member resumed contact with a majority of the members in the group. Regular operation is re-established.'
^ Found warnings in /Users/laurynas/percona/obj-mysql-8.0.2-pp-asan-debug-openssl/mysql-test/var/log/mysqld.2.err
ok