create database airflow;

sql_alchemy_conn = mysql+mysqldb://root:******@47.98.**.**:****/airflow

root@iZt4n4bv565ho9ijn61932Z:/xx/airflow/airflow# docker run --rm --name airflow -v /xx/airflow/airflow:/root/airflow  apache/airflow:master-ci db init

DB: mysql+mysqldb://root:***@47.98.**.**:****/airflow
[2020-05-30 09:13:59,288] {db.py:610} INFO - Creating tables
[2020-05-30 09:13:59,290] {db.py:565} INFO - Creating tables
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade  -> e3a246e0dc1, current schema
INFO  [alembic.runtime.migration] Running upgrade e3a246e0dc1 -> 1507a7289a2f, create is_encrypted
INFO  [alembic.runtime.migration] Running upgrade 1507a7289a2f -> 13eb55f81627, maintain history for compatibility with earlier migrations
INFO  [alembic.runtime.migration] Running upgrade 13eb55f81627 -> 338e90f54d61, More logging into task_instance
INFO  [alembic.runtime.migration] Running upgrade 338e90f54d61 -> 52d714495f0, job_id indices
INFO  [alembic.runtime.migration] Running upgrade 52d714495f0 -> 502898887f84, Adding extra to Log
INFO  [alembic.runtime.migration] Running upgrade 502898887f84 -> 1b38cef5b76e, add dagrun
INFO  [alembic.runtime.migration] Running upgrade 1b38cef5b76e -> 2e541a1dcfed, task_duration
INFO  [alembic.runtime.migration] Running upgrade 2e541a1dcfed -> 40e67319e3a9, dagrun_config
INFO  [alembic.runtime.migration] Running upgrade 40e67319e3a9 -> 561833c1c74b, add password column to user
INFO  [alembic.runtime.migration] Running upgrade 561833c1c74b -> 4446e08588, dagrun start end
INFO  [alembic.runtime.migration] Running upgrade 4446e08588 -> bbc73705a13e, Add notification_sent column to sla_miss
INFO  [alembic.runtime.migration] Running upgrade bbc73705a13e -> bba5a7cfc896, Add a column to track the encryption state of the 'Extra' field in connection
INFO  [alembic.runtime.migration] Running upgrade bba5a7cfc896 -> 1968acfc09e3, add is_encrypted column to variable table
INFO  [alembic.runtime.migration] Running upgrade 1968acfc09e3 -> 2e82aab8ef20, rename user table
INFO  [alembic.runtime.migration] Running upgrade 2e82aab8ef20 -> 211e584da130, add TI state index
INFO  [alembic.runtime.migration] Running upgrade 211e584da130 -> 64de9cddf6c9, add task fails journal table
INFO  [alembic.runtime.migration] Running upgrade 64de9cddf6c9 -> f2ca10b85618, add dag_stats table
INFO  [alembic.runtime.migration] Running upgrade f2ca10b85618 -> 4addfa1236f1, Add fractional seconds to mysql tables
INFO  [alembic.runtime.migration] Running upgrade 4addfa1236f1 -> 8504051e801b, xcom dag task indices
INFO  [alembic.runtime.migration] Running upgrade 8504051e801b -> 5e7d17757c7a, add pid field to TaskInstance
INFO  [alembic.runtime.migration] Running upgrade 5e7d17757c7a -> 127d2bf2dfa7, Add dag_id/state index on dag_run table
INFO  [alembic.runtime.migration] Running upgrade 127d2bf2dfa7 -> cc1e65623dc7, add max tries column to task instance
INFO  [alembic.runtime.migration] Running upgrade cc1e65623dc7 -> bdaa763e6c56, Make xcom value column a large binary
INFO  [alembic.runtime.migration] Running upgrade bdaa763e6c56 -> 947454bf1dff, add ti job_id index
INFO  [alembic.runtime.migration] Running upgrade 947454bf1dff -> d2ae31099d61, Increase text size for MySQL (not relevant for other DBs' text types)
INFO  [alembic.runtime.migration] Running upgrade d2ae31099d61 -> 0e2a74e0fc9f, Add time zone awareness
INFO  [alembic.runtime.migration] Running upgrade d2ae31099d61 -> 33ae817a1ff4, kubernetes_resource_checkpointing
INFO  [alembic.runtime.migration] Running upgrade 33ae817a1ff4 -> 27c6a30d7c24, kubernetes_resource_checkpointing
INFO  [alembic.runtime.migration] Running upgrade 27c6a30d7c24 -> 86770d1215c0, add kubernetes scheduler uniqueness
INFO  [alembic.runtime.migration] Running upgrade 86770d1215c0, 0e2a74e0fc9f -> 05f30312d566, merge heads
INFO  [alembic.runtime.migration] Running upgrade 05f30312d566 -> f23433877c24, fix mysql not null constraint
INFO  [alembic.runtime.migration] Running upgrade f23433877c24 -> 856955da8476, fix sqlite foreign key
INFO  [alembic.runtime.migration] Running upgrade 856955da8476 -> 9635ae0956e7, index-faskfail
INFO  [alembic.runtime.migration] Running upgrade 9635ae0956e7 -> dd25f486b8ea, add idx_log_dag
INFO  [alembic.runtime.migration] Running upgrade dd25f486b8ea -> bf00311e1990, add index to taskinstance
INFO  [alembic.runtime.migration] Running upgrade 9635ae0956e7 -> 0a2a5b66e19d, add task_reschedule table
INFO  [alembic.runtime.migration] Running upgrade 0a2a5b66e19d, bf00311e1990 -> 03bc53e68815, merge_heads_2
INFO  [alembic.runtime.migration] Running upgrade 03bc53e68815 -> 41f5f12752f8, add superuser field
INFO  [alembic.runtime.migration] Running upgrade 41f5f12752f8 -> c8ffec048a3b, add fields to dag
INFO  [alembic.runtime.migration] Running upgrade 41f5f12752f8 -> cf5dc11e79ad, drop_user_and_chart
INFO  [alembic.runtime.migration] Running upgrade c8ffec048a3b -> dd4ecb8fbee3, Add schedule interval to dag
INFO  [alembic.runtime.migration] Running upgrade dd4ecb8fbee3, cf5dc11e79ad -> 4ebbffe0a39a, Merge heads
INFO  [alembic.runtime.migration] Running upgrade 4ebbffe0a39a -> 939bb1e647c8, task reschedule fk on cascade delete
INFO  [alembic.runtime.migration] Running upgrade 939bb1e647c8 -> 6e96a59344a4, Make TaskInstance.pool not nullable
INFO  [alembic.runtime.migration] Running upgrade 939bb1e647c8 -> 004c1210f153, increase queue name size limit
INFO  [alembic.runtime.migration] Running upgrade 004c1210f153 -> bbf4a7ad0465, Remove id column from xcom
Traceback (most recent call last):
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1284, in _execute_context
    cursor, statement, parameters, context
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 590, in do_execute
    cursor.execute(statement, parameters)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 255, in execute
    self.errorhandler(self, exc, value)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/connections.py", line 50, in defaulterrorhandler
    raise errorvalue
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 252, in execute
    res = self._query(query)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 378, in _query
    db.query(q)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/connections.py", line 280, in query
    _mysql.connection.query(self, query)
_mysql_exceptions.OperationalError: (1071, 'Specified key was too long; max key length is 3072 bytes')

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/usr/local/bin/airflow", line 11, in <module>
    load_entry_point('apache-airflow', 'console_scripts', 'airflow')()
  File "/opt/airflow/airflow/__main__.py", line 40, in main
    args.func(args)
  File "/opt/airflow/airflow/cli/cli_parser.py", line 52, in command
    return func(*args, **kwargs)
  File "/opt/airflow/airflow/cli/commands/db_command.py", line 31, in initdb
    db.initdb()
  File "/opt/airflow/airflow/utils/db.py", line 546, in initdb
    upgradedb()
  File "/opt/airflow/airflow/utils/db.py", line 614, in upgradedb
    command.upgrade(config, 'heads')
  File "/usr/local/lib/python3.6/site-packages/alembic/command.py", line 298, in upgrade
    script.run_env()
  File "/usr/local/lib/python3.6/site-packages/alembic/script/base.py", line 489, in run_env
    util.load_python_file(self.dir, "env.py")
  File "/usr/local/lib/python3.6/site-packages/alembic/util/pyfiles.py", line 98, in load_python_file
    module = load_module_py(module_id, path)
  File "/usr/local/lib/python3.6/site-packages/alembic/util/compat.py", line 184, in load_module_py
    spec.loader.exec_module(module)
  File "<frozen importlib._bootstrap_external>", line 678, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/opt/airflow/airflow/migrations/env.py", line 107, in <module>
    run_migrations_online()
  File "/opt/airflow/airflow/migrations/env.py", line 101, in run_migrations_online
    context.run_migrations()
  File "<string>", line 8, in run_migrations
  File "/usr/local/lib/python3.6/site-packages/alembic/runtime/environment.py", line 846, in run_migrations
    self.get_context().run_migrations(**kw)
  File "/usr/local/lib/python3.6/site-packages/alembic/runtime/migration.py", line 520, in run_migrations
    step.migration_fn(**kw)
  File "/opt/airflow/airflow/migrations/versions/bbf4a7ad0465_remove_id_column_from_xcom.py", line 42, in upgrade
    bop.create_primary_key('pk_xcom', ['dag_id', 'task_id', 'key', 'execution_date'])
  File "/usr/local/lib/python3.6/contextlib.py", line 88, in __exit__
    next(self.gen)
  File "/usr/local/lib/python3.6/site-packages/alembic/operations/base.py", line 354, in batch_alter_table
    impl.flush()
  File "/usr/local/lib/python3.6/site-packages/alembic/operations/batch.py", line 83, in flush
    fn(*arg, **kw)
  File "/usr/local/lib/python3.6/site-packages/alembic/ddl/impl.py", line 244, in add_constraint
    self._exec(schema.AddConstraint(const))
  File "/usr/local/lib/python3.6/site-packages/alembic/ddl/impl.py", line 140, in _exec
    return conn.execute(construct, *multiparams, **params)
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1020, in execute
    return meth(self, multiparams, params)
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/sql/ddl.py", line 72, in _execute_on_connection
    return connection._execute_ddl(self, multiparams, params)
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1082, in _execute_ddl
    compiled,
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1324, in _execute_context
    e, statement, parameters, cursor, context
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1518, in _handle_dbapi_exception
    sqlalchemy_exception, with_traceback=exc_info[2], from_=e
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 178, in raise_
    raise exception
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1284, in _execute_context
    cursor, statement, parameters, context
  File "/usr/local/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 590, in do_execute
    cursor.execute(statement, parameters)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 255, in execute
    self.errorhandler(self, exc, value)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/connections.py", line 50, in defaulterrorhandler
    raise errorvalue
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 252, in execute
    res = self._query(query)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/cursors.py", line 378, in _query
    db.query(q)
  File "/usr/local/lib/python3.6/site-packages/MySQLdb/connections.py", line 280, in query
    _mysql.connection.query(self, query)
sqlalchemy.exc.OperationalError: (_mysql_exceptions.OperationalError) (1071, 'Specified key was too long; max key length is 3072 bytes')
[SQL: ALTER TABLE xcom ADD CONSTRAINT pk_xcom PRIMARY KEY (dag_id, task_id, `key`, execution_date)]
(Background on this error at: http://sqlalche.me/e/e3q8)