def migrate(db, migrations_dir):
"""
Returns: accumulated_migrations, all_migrations_ran_successfully
accumulated_migrations is a list of migration names that ran successfully.
all_migrations_ran_successfully is a bool indicating overall success
"""
ensure_schema_migrations_tables(db)
accumulated_migrations = []
if obtain_migration_lock(db):
# So two servers don't run migration at same time
migrations = get_migrations_to_run(db, migrations_dir)
for i, (migration_name, migration) in enumerate(migrations):
logging.info('Running ' + migration_name)
try:
migration.run(db)
except Exception as e:
exc_info = sys.exc_info()
handle_failed_migration(db, exc_info)
return accumulated_migrations, False
logging.info('Finished migration ' + migration_name)
mark_migration_done(db, migration_name)
accumulated_migrations += migration_name
release_migration_lock(db)
return accumulated_migrations, True
def migrate(db, migrations_dir):
"""
Returns: accumulated_migrations, all_migrations_ran_successfully
accumulated_migrations is a list of migration names that ran successfully.
all_migrations_ran_successfully is a bool indicating overall success
"""
ensure_schema_migrations_tables(db)
accumulated_migrations = []
if obtain_migration_lock(db):
# So two servers don't run migration at same time
migrations = get_migrations_to_run(db, migrations_dir)
for i, (migration_name, migration) in enumerate(migrations):
logging.info('Running ' + migration_name )
try:
migration.run(db)
except Exception as e:
exc_info = sys.exc_info()
handle_failed_migration(db, exc_info)
return accumulated_migrations, False
logging.info('Finished migration ' + migration_name )
mark_migration_done(db, migration_name)
accumulated_migrations += migration_name
release_migration_lock(db)
return accumulated_migrations, True
def _exponential_splay(self, retry):
if IS_TEST:
sleep_coeff = 0
else:
sleep_coeff = 1
# random => ! herd
# Max: 2 ** 4 = 16 seconds
time_to_sleep = sleep_coeff * 2**retry * random.random()
logging.info('sleeping for %f seconds' % time_to_sleep)
time.sleep(time_to_sleep)
def _change_throughput(self, new_throughput, boto_table, table_name):
try:
logging.warn('Attempting to increase throughput of ' + table_name)
self.connection.update_table(table_name,
provisioned_throughput=new_throughput)
except Exception as e:
# TODO: Fail gracefully here on Validation Exception.
# TODO: Don't refresh table info after getting throughput exceeded
exc_info = sys.exc_info()
logging.error(
'Could not increase table throughput will continue '
'retrying. Error was: %s %s %s', exc_info[0], exc_info[1],
exc_info[2])
else:
logging.info('Successfully increased throughput of ' + table_name)
def obtain_migration_lock(db):
# lock = db.get_item(table_name=META_TABLE_NAME, tenant_id=SUPER_TENANT_ID,
# purpose='check status', name=MIGRATION_META_STATUS_KEY)
try:
db.put_item(table_name=META_TABLE_NAME,
item={
META_KEY_NAME: MIGRATION_META_STATUS_KEY,
META_VALUE_NAME: YES_STATUS
},
tenant_id=SUPER_TENANT_ID,
purpose='obtain migration lock',
overwrite=True,
condition=META_VALUE_NAME + " = :status",
vars={':status': {'S': NO_STATUS}})
except ClariDynamo.ClariDynamoConditionCheckFailedException as e:
logging.info('Could not get migration lock, other process running.')
return False
return True
def obtain_migration_lock(db):
# lock = db.get_item(table_name=META_TABLE_NAME, tenant_id=SUPER_TENANT_ID,
# purpose='check status', name=MIGRATION_META_STATUS_KEY)
try:
db.put_item(table_name=META_TABLE_NAME,
item={
META_KEY_NAME: MIGRATION_META_STATUS_KEY,
META_VALUE_NAME: YES_STATUS
},
tenant_id=SUPER_TENANT_ID,
purpose='obtain migration lock',
overwrite=True,
condition=META_VALUE_NAME + " = :status",
vars={':status': {
'S': NO_STATUS
}})
except ClariDynamo.ClariDynamoConditionCheckFailedException as e:
logging.info('Could not get migration lock, other process running.')
return False
return True
def wait_for_table_to_become_active(self, boto_table, table_name):
while self.get_table_status(boto_table) != 'ACTIVE':
logging.info('Waiting for table to finish creating')
sleep(1)