def mapper_init(self):
""" mrjob initialization.
Should you decide to override, you should call 'super' to invoke
this method.
"""
yaml_data = load_from_file(self.options.extractions)
schema = RedShiftLogSchema(yaml.load(yaml_data))
self.schema = schema
self.table_name_to_columns = dict((table_name, [
Column.create_from_table(table, column)
for column in table['columns']
]) for table_name, table in schema.tables().iteritems())
self.table_name_to_table = dict(
(table_name,
Table.create(table,
columns=self.table_name_to_columns[table_name]))
for table_name, table in schema.tables().iteritems())
self.table_name_to_output_order = dict(
(table_name,
[column.name for column in columns if not column.is_noop])
for table_name, columns in self.table_name_to_columns.iteritems())
self.redshift_export = RedshiftExportProtocol(
delimiter=self.options.column_delimiter)
error_table_name, error_table = self.schema.get_error_table()
self.error_tbl_name = error_table_name
self.error_tbl_output_order = [
c['log_key'] for c in error_table['columns']
]
def mapper_init(self):
""" mrjob initialization.
Should you decide to override, you should call 'super' to invoke
this method.
"""
yaml_data = load_from_file(self.options.extractions)
schema = RedShiftLogSchema(yaml.load(yaml_data))
self.schema = schema
self.table_name_to_columns = dict(
(table_name,
[Column.create_from_table(table, column)
for column in table['columns']])
for table_name, table in schema.tables().iteritems()
)
self.table_name_to_table = dict(
(table_name,
Table.create(table,
columns=self.table_name_to_columns[table_name]))
for table_name, table in schema.tables().iteritems()
)
self.table_name_to_output_order = dict(
(table_name,
[column.name for column in columns if not column.is_noop])
for table_name, columns in self.table_name_to_columns.iteritems()
)
self.redshift_export = RedshiftExportProtocol(
delimiter=self.options.column_delimiter
)
error_table_name, error_table = self.schema.get_error_table()
self.error_tbl_name = error_table_name
self.error_tbl_output_order = [c['log_key'] for c in error_table['columns']]
class MRRedshiftETL(MRJob):
OUTPUT_PROTOCOL = RawProtocol
HADOOP_OUTPUT_FORMAT = 'oddjob.MultipleValueOutputFormat'
def configure_options(self):
super(MRRedshiftETL, self).configure_options()
self.add_file_option(
'--extractions',
type='string',
default="schema/db.yaml",
help="Yaml file specifies what information to extract "
"(default: %default)")
self.add_passthrough_option(
"--column-delimiter",
type='string',
default='|',
help="column delimiter",
)
def mapper_init(self):
""" mrjob initialization.
Should you decide to override, you should call 'super' to invoke
this method.
"""
yaml_data = load_from_file(self.options.extractions)
schema = RedShiftLogSchema(yaml.load(yaml_data))
self.schema = schema
self.table_name_to_columns = dict((table_name, [
Column.create_from_table(table, column)
for column in table['columns']
]) for table_name, table in schema.tables().iteritems())
self.table_name_to_table = dict(
(table_name,
Table.create(table,
columns=self.table_name_to_columns[table_name]))
for table_name, table in schema.tables().iteritems())
self.table_name_to_output_order = dict(
(table_name,
[column.name for column in columns if not column.is_noop])
for table_name, columns in self.table_name_to_columns.iteritems())
self.redshift_export = RedshiftExportProtocol(
delimiter=self.options.column_delimiter)
error_table_name, error_table = self.schema.get_error_table()
self.error_tbl_name = error_table_name
self.error_tbl_output_order = [
c['log_key'] for c in error_table['columns']
]
def mapper_final(self):
for table_name in self.table_name_to_table:
table = self.table_name_to_table[table_name]
if len(table.truncated_columns):
log.info("{0}: truncated columns {1}".format(
table_name, table.truncated_columns))
def derive_metric(self,
name_to_object=None,
metric_name=None,
context=None):
"""define this in your own class to support derived field
For example, if you want to generate a derived field called
odd_or_even for a boolean column.
name_to_object = {'session': {'random': 77}}
def derive_metric(
self, name_to_object=None, metric_name=None, context=None
):
if metric_name == 'odd_or_even':
return bool(get_deep('session.random') % 2 == 0)
raise ValueError('I don't recognize this metric')
name_to_object: a dict in which key is referenced in your schema
and generated by your mapper, whereas value
is generated by your mapper.
metric_name: name of the derived metric
context: a dict contains the following:
'self': is the value of parent
'index': is the index value of an item being processed in an array
Returns:
a scalar fit for your derived metric
"""
raise NotImplementedError
def emit_exception_row(self, value):
"""Use this inside your mapper function to generate
error rows for Redshift tables on exception
value: variable passed to mapper function
"""
exc_type, exc_value, exc_tb = sys.exc_info()
error_msg = {
'crash_tb':
''.join(traceback.format_tb(exc_tb)),
'crash_exc':
traceback.format_exception_only(exc_type, exc_value)[0].strip()
}
now_utc_ms = long(time.mktime(datetime.utcnow().timetuple())) * 1000
row = {
'starttime': now_utc_ms, # starttime in UTC millisecs
'filename': derive_filename(None), # source filename with error
'line_number': None, # line number (not known with mrjob)
'raw_line': value, # raw line
'error_reason': error_msg['crash_exc'], # error summary
'error_detail': error_msg # error detail
}
self.redshift_export.given_output_order = self.error_tbl_output_order
return self.error_tbl_name, self.redshift_export.write(None, row)
def emit_rows_for_tables(self, name_to_object):
"""Use this inside your mapper function to generate
rows for Redshift tables
name_to_object: a dictionary with keys that may be
referenced by your schema
"""
for table_name, table in self.table_name_to_table.iteritems():
for row in table.value_iterator(name_to_object=name_to_object,
derive_metric=self.derive_metric):
self.redshift_export.given_output_order = \
self.table_name_to_output_order[table_name]
yield table_name, self.redshift_export.write(None, row)
def redshift_export_encoder():
return RedshiftExportProtocol()
class MRRedshiftETL(MRJob):
OUTPUT_PROTOCOL = RawProtocol
HADOOP_OUTPUT_FORMAT = 'oddjob.MultipleValueOutputFormat'
def configure_options(self):
super(MRRedshiftETL, self).configure_options()
self.add_file_option(
'--extractions', type='string', default="schema/db.yaml",
help="Yaml file specifies what information to extract "
"(default: %default)")
self.add_passthrough_option(
"--column-delimiter", type='string', default='|',
help="column delimiter",
)
def mapper_init(self):
""" mrjob initialization.
Should you decide to override, you should call 'super' to invoke
this method.
"""
yaml_data = load_from_file(self.options.extractions)
schema = RedShiftLogSchema(yaml.load(yaml_data))
self.schema = schema
self.table_name_to_columns = dict(
(table_name,
[Column.create_from_table(table, column)
for column in table['columns']])
for table_name, table in schema.tables().iteritems()
)
self.table_name_to_table = dict(
(table_name,
Table.create(table,
columns=self.table_name_to_columns[table_name]))
for table_name, table in schema.tables().iteritems()
)
self.table_name_to_output_order = dict(
(table_name,
[column.name for column in columns if not column.is_noop])
for table_name, columns in self.table_name_to_columns.iteritems()
)
self.redshift_export = RedshiftExportProtocol(
delimiter=self.options.column_delimiter
)
error_table_name, error_table = self.schema.get_error_table()
self.error_tbl_name = error_table_name
self.error_tbl_output_order = [c['log_key'] for c in error_table['columns']]
def mapper_final(self):
for table_name in self.table_name_to_table:
table = self.table_name_to_table[table_name]
if len(table.truncated_columns):
log.info("{0}: truncated columns {1}".format(
table_name, table.truncated_columns
))
def derive_metric(
self, name_to_object=None, metric_name=None, context=None
):
"""define this in your own class to support derived field
For example, if you want to generate a derived field called
odd_or_even for a boolean column.
name_to_object = {'session': {'random': 77}}
def derive_metric(
self, name_to_object=None, metric_name=None, context=None
):
if metric_name == 'odd_or_even':
return bool(get_deep('session.random') % 2 == 0)
raise ValueError('I don't recognize this metric')
name_to_object: a dict in which key is referenced in your schema
and generated by your mapper, whereas value
is generated by your mapper.
metric_name: name of the derived metric
context: a dict contains the following:
'self': is the value of parent
'index': is the index value of an item being processed in an array
Returns:
a scalar fit for your derived metric
"""
raise NotImplementedError
def emit_exception_row(self, value):
"""Use this inside your mapper function to generate
error rows for Redshift tables on exception
value: variable passed to mapper function
"""
exc_type, exc_value, exc_tb = sys.exc_info()
error_msg = {
'crash_tb': ''.join(traceback.format_tb(exc_tb)),
'crash_exc': traceback.format_exception_only(
exc_type, exc_value
)[0].strip()
}
now_utc_ms = long(time.mktime(datetime.utcnow().timetuple())) * 1000
row = {
'starttime': now_utc_ms, # starttime in UTC millisecs
'filename': derive_filename(None), # source filename with error
'line_number': None, # line number (not known with mrjob)
'raw_line': value, # raw line
'error_reason': error_msg['crash_exc'], # error summary
'error_detail': error_msg # error detail
}
self.redshift_export.given_output_order = self.error_tbl_output_order
return self.error_tbl_name, self.redshift_export.write(None, row)
def emit_rows_for_tables(self, name_to_object):
"""Use this inside your mapper function to generate
rows for Redshift tables
name_to_object: a dictionary with keys that may be
referenced by your schema
"""
for table_name, table in self.table_name_to_table.iteritems():
for row in table.value_iterator(name_to_object=name_to_object,
derive_metric=self.derive_metric):
self.redshift_export.given_output_order = \
self.table_name_to_output_order[table_name]
yield table_name, self.redshift_export.write(None, row)
