Mistakes
* should have noticed earlier that stage and prod were already configured to cycle gunicorn workers based on a request cap due to longstanding memory leak issues.
Loading prod/loadtest database schemas for testing migrations locally
Dump schema from replica
# note single space preceding next two lines prod_readonly_pass='' loadtest_readonly_pass='' ssh pwnage101@tools-gp.edx.org mysqldump -u read_only -h prod-edx-replica-rds.edx.org -p"\"$prod_readonly_pass\"" --no-data --lock-tables=false wwc > prod_replica_wwc_schemas.sql ssh pwnage101@tools-gp.edx.org mysqldump -u read_only -h loadtest-edx-rds.edx.org -p"\"$loadtest_readonly_pass\"" --no-data --lock-tables=false wwc > loadtest_wwc_schemas.sql
Sanitize auto increments for better diffs:
sed 's/ AUTO_INCREMENT=[0-9]*//' <prod_replica_wwc_schemas.sql >prod_replica_wwc_schemas_no_autoincrement.sql sed 's/ AUTO_INCREMENT=[0-9]*//' <loadtest_wwc_schemas.sql >loadtest_wwc_schemas_no_autoincrement.sql
Dump data from django_migrations from replica
ssh pwnage101@tools-gp.edx.org mysqldump -u read_only -h prod-edx-replica-rds.edx.org -p"\"$prod_readonly_pass\"" --lock-tables=false wwc django_migrations > prod_replica_wwc_django_migrations.sql ssh pwnage101@tools-gp.edx.org mysqldump -u read_only -h loadtest-edx-rds.edx.org -p"\"$loadtest_readonly_pass\"" --lock-tables=false wwc django_migrations > loadtest_wwc_django_migrations.sql
Load prod schema and django_migrations into devstack
docker-compose exec -T mysql mysql <<EOF DROP DATABASE edxapp; CREATE DATABASE edxapp; EOF docker-compose exec -T mysql mysql edxapp </path/to/prod_replica_wwc_schemas_no_autoincrement.sql docker-compose exec -T mysql mysql edxapp </path/to/prod_replica_wwc_django_migrations.sql
Test the auth migration
# in devstack repo: docker-compose exec -T mysql mysql <<EOF SET global general_log = 1; SET global log_output = 'table'; EOF # in lms-shell: ./manage.py lms migrate auth 0007_alter_validators_add_error_messages ./manage.py lms migrate auth 0008_alter_user_username_max_length # in devstack repo: echo 'select * from mysql.general_log' | docker-compose exec -T mysql mysql edxapp >mysql_general_log.csv
Testing migrations in a sanitized database recovered from prod
RDS/MySQL logging facilities
# enable general log (assumes "loadtest-edx-mysql56-1.11-with-query-log" is the name of the parameter group) rds-modify-db-parameter-group loadtest-edx-mysql56-1.11-with-query-log --parameters "name=general_log,value=ON,method=immediate" # retrieve general log echo 'select * from mysql.general_log' | ssh pwnage101@tools-gp.edx.org mysql -u read_only -h "<hostname_of_db>" >output.csv # retrieve binlog (must be root user) first_binlog=$(ssh tools-gp.edx.org mysql -u root -h "<hostname_of_db>" -e 'show binary logs;' --skip-column-names | head -n 1) ssh tools-gp.edx.org mysqlbinlog --raw --result-file=/tmp/binlogs/ --read-from-remote-server --to-last-log -u root -h "<hostname_of_db>" "$first_binlog" # view binlog locally scp -r tools-gp.edx.org:/tmp/binlogs . mysqlbinlog binlogs/*