caravel db_upgrade fails on MySql

[LAlbertalli]

The command caravel db_upgrade fails with the following error:

2016-05-26 21:49:47,019:INFO:flask_appbuilder.base:Registering class MyIndexView on menu 
2016-05-26 21:49:47,025:INFO:flask_appbuilder.base:Registering class UtilView on menu 
2016-05-26 21:49:47,030:INFO:flask_appbuilder.base:Registering class LocaleView on menu 
2016-05-26 21:49:47,035:INFO:flask_appbuilder.base:Registering class ResetPasswordView on menu 
2016-05-26 21:49:47,054:INFO:flask_appbuilder.base:Registering class ResetMyPasswordView on menu 
2016-05-26 21:49:47,071:INFO:flask_appbuilder.base:Registering class UserInfoEditView on menu 
2016-05-26 21:49:47,087:INFO:flask_appbuilder.base:Registering class AuthDBView on menu 
2016-05-26 21:49:47,099:INFO:flask_appbuilder.base:Registering class UserDBModelView on menu List Users
2016-05-26 21:49:47,150:INFO:flask_appbuilder.base:Registering class RoleModelView on menu List Roles
2016-05-26 21:49:47,200:INFO:flask_appbuilder.base:Registering class UserStatsChartView on menu User's Statistics
2016-05-26 21:49:47,233:INFO:flask_appbuilder.base:Registering class PermissionModelView on menu Base Permissions
2016-05-26 21:49:47,268:INFO:flask_appbuilder.base:Registering class ViewMenuModelView on menu Views/Menus
2016-05-26 21:49:47,306:INFO:flask_appbuilder.base:Registering class PermissionViewModelView on menu Permission on Views/Menus
2016-05-26 21:49:48,030:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.tables".
2016-05-26 21:49:48,030:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.tables.TableExtension".
2016-05-26 21:49:48,033:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.fenced_code".
2016-05-26 21:49:48,033:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.fenced_code.FencedCodeExtension".
2016-05-26 21:49:48,034:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.codehilite".
2016-05-26 21:49:48,034:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.codehilite.CodeHiliteExtension".
2016-05-26 21:49:48,043:INFO:flask_appbuilder.base:Registering class TableColumnInlineView on menu 
2016-05-26 21:49:48,081:INFO:flask_appbuilder.base:Registering class DruidColumnInlineView on menu 
2016-05-26 21:49:48,133:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.tables".
2016-05-26 21:49:48,133:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.tables.TableExtension".
2016-05-26 21:49:48,133:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.fenced_code".
2016-05-26 21:49:48,134:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.fenced_code.FencedCodeExtension".
2016-05-26 21:49:48,134:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.codehilite".
2016-05-26 21:49:48,134:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.codehilite.CodeHiliteExtension".
2016-05-26 21:49:48,138:INFO:flask_appbuilder.base:Registering class SqlMetricInlineView on menu 
2016-05-26 21:49:48,167:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.tables".
2016-05-26 21:49:48,167:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.tables.TableExtension".
2016-05-26 21:49:48,167:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.fenced_code".
2016-05-26 21:49:48,167:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.fenced_code.FencedCodeExtension".
2016-05-26 21:49:48,167:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.codehilite".
2016-05-26 21:49:48,167:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.codehilite.CodeHiliteExtension".
2016-05-26 21:49:48,172:INFO:flask_appbuilder.base:Registering class DruidMetricInlineView on menu 
2016-05-26 21:49:48,205:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.tables".
2016-05-26 21:49:48,205:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.tables.TableExtension".
2016-05-26 21:49:48,205:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.fenced_code".
2016-05-26 21:49:48,206:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.fenced_code.FencedCodeExtension".
2016-05-26 21:49:48,206:DEBUG:MARKDOWN:Successfuly imported extension module "markdown.extensions.codehilite".
2016-05-26 21:49:48,206:DEBUG:MARKDOWN:Successfully loaded extension "markdown.extensions.codehilite.CodeHiliteExtension".
2016-05-26 21:49:48,208:WARNING:flask_appbuilder.models.filters:Filter type not supported for column: password
2016-05-26 21:49:48,211:INFO:flask_appbuilder.base:Registering class DatabaseView on menu Databases
2016-05-26 21:49:48,261:INFO:flask_appbuilder.base:Registering class TableModelView on menu Tables
2016-05-26 21:49:48,312:INFO:flask_appbuilder.base:Registering class DruidClusterModelView on menu Druid Clusters
2016-05-26 21:49:48,365:INFO:flask_appbuilder.base:Registering class SliceModelView on menu Slices
2016-05-26 21:49:48,406:INFO:flask_appbuilder.base:Registering class SliceAsync on menu 
2016-05-26 21:49:48,454:INFO:flask_appbuilder.base:Registering class DashboardModelView on menu Dashboards
2016-05-26 21:49:48,505:INFO:flask_appbuilder.base:Registering class DashboardModelViewAsync on menu 
2016-05-26 21:49:48,540:INFO:flask_appbuilder.base:Registering class LogModelView on menu Action Log
2016-05-26 21:49:48,592:INFO:flask_appbuilder.base:Registering class DruidDatasourceModelView on menu Druid Datasources
2016-05-26 21:49:48,639:INFO:flask_appbuilder.base:Registering class R on menu 
2016-05-26 21:49:48,646:INFO:flask_appbuilder.base:Registering class Caravel on menu 
2016-05-26 21:49:48,709:INFO:flask_appbuilder.base:Registering class CssTemplateModelView on menu CSS Templates
INFO  [alembic.runtime.migration] Context impl MySQLImpl.
INFO  [alembic.runtime.migration] Will assume non-transactional DDL.
INFO  [alembic.runtime.migration] Running upgrade  -> 4e6a06bad7a8, Init
Traceback (most recent call last):
  File "/usr/bin/caravel", line 113, in <module>
    manager.run()
  File "/usr/lib/python2.7/site-packages/flask_script/__init__.py", line 412, in run
    result = self.handle(sys.argv[0], sys.argv[1:])
  File "/usr/lib/python2.7/site-packages/flask_script/__init__.py", line 383, in handle
    res = handle(*args, **config)
  File "/usr/lib/python2.7/site-packages/flask_script/commands.py", line 216, in __call__
    return self.run(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/flask_migrate/__init__.py", line 235, in upgrade
    command.upgrade(config, revision, sql=sql, tag=tag)
  File "/usr/lib/python2.7/site-packages/alembic/command.py", line 174, in upgrade
    script.run_env()
  File "/usr/lib/python2.7/site-packages/alembic/script/base.py", line 397, in run_env
    util.load_python_file(self.dir, 'env.py')
  File "/usr/lib/python2.7/site-packages/alembic/util/pyfiles.py", line 93, in load_python_file
    module = load_module_py(module_id, path)
  File "/usr/lib/python2.7/site-packages/alembic/util/compat.py", line 79, in load_module_py
    mod = imp.load_source(module_id, path, fp)
  File "/usr/lib/python2.7/site-packages/caravel/migrations/env.py", line 90, in <module>
    run_migrations_online()
  File "/usr/lib/python2.7/site-packages/caravel/migrations/env.py", line 83, in run_migrations_online
    context.run_migrations()
  File "<string>", line 8, in run_migrations
  File "/usr/lib/python2.7/site-packages/alembic/runtime/environment.py", line 797, in run_migrations
    self.get_context().run_migrations(**kw)
  File "/usr/lib/python2.7/site-packages/alembic/runtime/migration.py", line 312, in run_migrations
    step.migration_fn(**kw)
  File "/usr/lib/python2.7/site-packages/caravel/migrations/versions/4e6a06bad7a8_init.py", line 71, in upgrade
    sa.UniqueConstraint('datasource_name')
  File "<string>", line 8, in create_table
  File "<string>", line 3, in create_table
  File "/usr/lib/python2.7/site-packages/alembic/operations/ops.py", line 1098, in create_table
    return operations.invoke(op)
  File "/usr/lib/python2.7/site-packages/alembic/operations/base.py", line 318, in invoke
    return fn(self, operation)
  File "/usr/lib/python2.7/site-packages/alembic/operations/toimpl.py", line 101, in create_table
    operations.impl.create_table(table)
  File "/usr/lib/python2.7/site-packages/alembic/ddl/impl.py", line 194, in create_table
    self._exec(schema.CreateTable(table))
  File "/usr/lib/python2.7/site-packages/alembic/ddl/impl.py", line 118, in _exec
    return conn.execute(construct, *multiparams, **params)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 914, in execute
    return meth(self, multiparams, params)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/sql/ddl.py", line 68, in _execute_on_connection
    return connection._execute_ddl(self, multiparams, params)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 968, in _execute_ddl
    compiled
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 1146, in _execute_context
    context)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 1341, in _handle_dbapi_exception
    exc_info
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/util/compat.py", line 202, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/base.py", line 1139, in _execute_context
    context)
  File "/usr/lib64/python2.7/site-packages/sqlalchemy/engine/default.py", line 450, in do_execute
    cursor.execute(statement, parameters)
  File "/usr/lib64/python2.7/site-packages/MySQLdb/cursors.py", line 174, in execute
    self.errorhandler(self, exc, value)
  File "/usr/lib64/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
sqlalchemy.exc.OperationalError: (_mysql_exceptions.OperationalError) (1071, 'Specified key was too long; max key length is 767 bytes') [SQL: u'\nCREATE TABLE datasources (\n\tcreated_on DATETIME NOT NULL, \n\tchanged_on DATETIME NOT NULL, \n\tid INTEGER NOT NULL AUTO_INCREMENT, \n\tdatasource_name VARCHAR(256), \n\tis_featured BOOL, \n\tis_hidden BOOL, \n\tdescription TEXT, \n\tdefault_endpoint TEXT, \n\tuser_id INTEGER, \n\tcluster_name VARCHAR(250), \n\tcreated_by_fk INTEGER, \n\tchanged_by_fk INTEGER, \n\tPRIMARY KEY (id), \n\tUNIQUE (datasource_name), \n\tCHECK (is_featured IN (0, 1)), \n\tCHECK (is_hidden IN (0, 1)), \n\tFOREIGN KEY(user_id) REFERENCES ab_user (id), \n\tFOREIGN KEY(cluster_name) REFERENCES clusters (cluster_name), \n\tFOREIGN KEY(created_by_fk) REFERENCES ab_user (id), \n\tFOREIGN KEY(changed_by_fk) REFERENCES ab_user (id)\n)\n\n']

The app has been configured to use MySQL and the MySQL database is configured with

DEFAULT CHARACTER SET 'utf8'
DEFAULT COLLATE 'utf8_general_ci'

The operating system is CentOs 7.2 and the MySQL database is MySQL 5.5.44-37.3 (Percona Server Release 37.3).

My guess is that there are indexes on a varchar field that is too long (in utf8, each char is 4 bytes, so the limit is 191 char).

[x4base]

Which version of Caravel are you using? I suppose it should have been fixed in #459

[LAlbertalli]

I'm using 0.9.0.
I see that your patch have not been included in 0.9. When I looked up the error I've seen it committed at the same time 0.9.0 was released so I assumed it was in 0.9

This means I'll need to checkout from master hoping that it works (Yesterday was broken :-( but I hadn't had time to investigate)