def locate_replication_slot(conn_info):
with post_db.open_connection(conn_info, False) as conn:
with conn.cursor() as cur:
db_specific_slot = "stitch_{}".format(conn_info["dbname"])
cur.execute(
"SELECT * FROM pg_replication_slots WHERE slot_name = %s AND plugin = %s",
(db_specific_slot, "wal2json"),
)
if len(cur.fetchall()) == 1:
LOGGER.info("using pg_replication_slot %s", db_specific_slot)
return db_specific_slot
cur.execute(
"""SELECT * FROM pg_replication_slots
WHERE slot_name = 'stitch'
AND plugin = 'wal2json'"""
)
if len(cur.fetchall()) == 1:
LOGGER.info("using pg_replication_slot 'stitch'")
return "stitch"
raise Exception(
"Unable to find replication slot (stitch || {} with wal2json".format(
db_specific_slot
)
)
def row_to_singer_message(
stream, row, version, columns, time_extracted, md_map, conn_info
):
row_to_persist = ()
md_map[("properties", "_sdc_deleted_at")] = {
"sql-datatype": "timestamp with time zone"
}
md_map[("properties", "_sdc_lsn")] = {"sql-datatype": "character varying"}
for idx, elem in enumerate(row):
sql_datatype = md_map.get(("properties", columns[idx])).get("sql-datatype")
if not sql_datatype:
LOGGER.info("No sql-datatype found for stream %s: %s", stream, columns[idx])
raise Exception("Unable to find sql-datatype for stream {}".format(stream))
cleaned_elem = selected_value_to_singer_value(elem, sql_datatype, conn_info)
row_to_persist += (cleaned_elem,)
rec = dict(zip(columns, row_to_persist))
return singer.RecordMessage(
stream=post_db.calculate_destination_stream_name(stream, md_map),
record=rec,
version=version,
time_extracted=time_extracted,
)
def open_connection(conn_config, logical_replication=False):
cfg = {
"host": conn_config["host"],
"dbname": conn_config["dbname"],
"user": conn_config["user"],
"password": conn_config["password"],
"port": conn_config["port"],
"connect_timeout": 30,
}
if conn_config.get("sslmode"):
cfg["sslmode"] = conn_config["sslmode"]
if cfg["sslmode"] == "verify-ca":
cfg["sslrootcert"] = conn_config.get("sslrootcert")
cfg["sslcert"] = conn_config.get("sslcert")
cfg["sslkey"] = conn_config.get("sslkey")
if logical_replication:
cfg["connection_factory"] = psycopg2.extras.LogicalReplicationConnection
LOGGER.info("Trying to connect with config = %s", str(cfg))
conn = psycopg2.connect(**cfg)
LOGGER.info("Connected with sslmode = %s",
conn.get_dsn_parameters().get("sslmode", "unknown"))
return conn
def do_sync_incremental(conn_config, stream, state, desired_columns, md_map):
replication_key = md_map.get((), {}).get("replication-key")
LOGGER.info(
"Stream %s is using incremental replication with replication key %s",
stream["tap_stream_id"],
replication_key,
)
stream_state = state.get("bookmarks", {}).get(stream["tap_stream_id"])
illegal_bk_keys = set(stream_state.keys()).difference(
set([
"replication_key", "replication_key_value", "version",
"last_replication_method"
]))
if len(illegal_bk_keys) != 0:
raise Exception(
"invalid keys found in state: {}".format(illegal_bk_keys))
state = singer.write_bookmark(state, stream["tap_stream_id"],
"replication_key", replication_key)
sync_common.send_schema_message(stream, [replication_key])
state = incremental.sync_table(conn_config, stream, state, desired_columns,
md_map)
return state
def sync_view(conn_info, stream, state, desired_columns, md_map):
time_extracted = utils.now()
# before writing the table version to state, check if we had one to begin with
first_run = singer.get_bookmark(state, stream["tap_stream_id"],
"version") is None
nascent_stream_version = int(time.time() * 1000)
state = singer.write_bookmark(state, stream["tap_stream_id"], "version",
nascent_stream_version)
singer.write_message(singer.StateMessage(value=copy.deepcopy(state)))
schema_name = md_map.get(()).get("schema-name")
escaped_columns = map(post_db.prepare_columns_sql, desired_columns)
activate_version_message = singer.ActivateVersionMessage(
stream=post_db.calculate_destination_stream_name(stream, md_map),
version=nascent_stream_version,
)
if first_run:
singer.write_message(activate_version_message)
with metrics.record_counter(None) as counter:
with post_db.open_connection(conn_info) as conn:
with conn.cursor(cursor_factory=psycopg2.extras.DictCursor,
name="stitch_cursor") as cur:
cur.itersize = post_db.cursor_iter_size
select_sql = "SELECT {} FROM {}".format(
",".join(escaped_columns),
post_db.fully_qualified_table_name(schema_name,
stream["table_name"]),
)
LOGGER.info("select %s with itersize %s", select_sql,
cur.itersize)
cur.execute(select_sql)
rows_saved = 0
for rec in cur:
record_message = post_db.selected_row_to_singer_message(
stream, rec, nascent_stream_version, desired_columns,
time_extracted, md_map)
singer.write_message(record_message)
rows_saved = rows_saved + 1
if rows_saved % conn_info["emit_state_every_n_rows"] == 0:
singer.write_message(
singer.StateMessage(value=copy.deepcopy(state)))
counter.increment()
# always send the activate version whether first run or subsequent
singer.write_message(activate_version_message)
return state
def get_pg_version(cur):
cur.execute("SELECT version()")
res = cur.fetchone()[0]
version_match = re.match(r"PostgreSQL (\d+)", res)
if not version_match:
raise Exception("unable to determine PostgreSQL version from {}".format(res))
version = int(version_match.group(1))
LOGGER.info("Detected PostgresSQL version: %s", version)
return version
def do_sync_full_table(conn_config, stream, state, desired_columns, md_map):
LOGGER.info("Stream %s is using full_table replication",
stream["tap_stream_id"])
sync_common.send_schema_message(stream, [])
if md_map.get((), {}).get("is-view"):
state = full_table.sync_view(conn_config, stream, state,
desired_columns, md_map)
else:
state = full_table.sync_table(conn_config, stream, state,
desired_columns, md_map)
return state
def add_automatic_properties(stream, conn_config):
stream["schema"]["properties"]["_sdc_deleted_at"] = {
"type": ["null", "string"],
"format": "date-time",
}
if conn_config.get("debug_lsn"):
LOGGER.info("debug_lsn is ON")
stream["schema"]["properties"]["_sdc_lsn"] = {"type": ["null", "string"]}
else:
LOGGER.info("debug_lsn is OFF")
return stream
def fetch_max_replication_key(conn_config, replication_key, schema_name, table_name):
with post_db.open_connection(conn_config, False) as conn:
with conn.cursor() as cur:
max_key_sql = """SELECT max({}) FROM {}""".format(
post_db.prepare_columns_sql(replication_key),
post_db.fully_qualified_table_name(schema_name, table_name),
)
LOGGER.info("determine max replication key value: %s", max_key_sql)
cur.execute(max_key_sql)
max_key = cur.fetchone()[0]
LOGGER.info("max replication key value: %s", max_key)
return max_key
def do_sync(conn_config, catalog, default_replication_method, state):
currently_syncing = singer.get_currently_syncing(state)
streams = list(filter(is_selected_via_metadata, catalog["streams"]))
streams.sort(key=lambda s: s["tap_stream_id"])
LOGGER.info("Selected streams: %s ",
list(map(lambda s: s["tap_stream_id"], streams)))
if any_logical_streams(streams, default_replication_method):
LOGGER.info("Use of logical replication requires fetching an lsn...")
end_lsn = logical_replication.fetch_current_lsn(conn_config)
LOGGER.info("End LSN: %s ", end_lsn)
else:
end_lsn = None
sync_method_lookup, traditional_streams, logical_streams = sync_method_for_streams(
streams, state, default_replication_method)
if currently_syncing:
LOGGER.info("found currently_syncing: %s", currently_syncing)
currently_syncing_stream = list(
filter(lambda s: s["tap_stream_id"] == currently_syncing,
traditional_streams))
if currently_syncing_stream is None:
LOGGER.warning(
"Can't find currently_syncing(%s) in selected traditional streams(%s). Will ignore",
currently_syncing,
list(map(lambda s: s["tap_stream_id"], traditional_streams)),
)
other_streams = list(
filter(lambda s: s["tap_stream_id"] != currently_syncing,
traditional_streams))
traditional_streams = currently_syncing_stream + other_streams
else:
LOGGER.info("No currently_syncing found")
for stream in traditional_streams:
state = sync_traditional_stream(
conn_config, stream, state,
sync_method_lookup[stream["tap_stream_id"]], end_lsn)
logical_streams.sort(key=lambda s: metadata.to_map(s["metadata"]).get(
()).get("database-name"))
for dbname, streams in itertools.groupby(
logical_streams, lambda s: metadata.to_map(s["metadata"]).get(
()).get("database-name")):
conn_config["dbname"] = dbname
state = sync_logical_streams(conn_config, list(streams), state,
end_lsn)
return state
def attempt_connection_to_db(conn_config, dbname):
nascent_config = copy.deepcopy(conn_config)
nascent_config["dbname"] = dbname
LOGGER.info("(%s) Testing connectivity...", dbname)
try:
conn = post_db.open_connection(nascent_config)
LOGGER.info("(%s) connectivity verified", dbname)
conn.close()
return True
except Exception as err:
LOGGER.warning(
'Unable to connect to %s. This is OK if you do not replicate from this database: "%s"',
dbname,
err,
)
return False
def sync_logical_streams(conn_config, logical_streams, state, end_lsn):
if logical_streams:
LOGGER.info(
"Pure Logical Replication upto lsn %s for (%s)",
end_lsn,
list(map(lambda s: s["tap_stream_id"], logical_streams)),
)
logical_streams = list(
map(
lambda s: logical_replication.add_automatic_properties(
s, conn_config),
logical_streams,
))
state = logical_replication.sync_tables(conn_config, logical_streams,
state, end_lsn)
return state
def do_discovery(conn_config):
all_streams = []
with post_db.open_connection(conn_config) as conn:
with conn.cursor(cursor_factory=psycopg2.extras.DictCursor,
name="stitch_cursor") as cur:
cur.itersize = post_db.cursor_iter_size
sql = """SELECT datname
FROM pg_database
WHERE datistemplate = false
AND datname != 'rdsadmin'"""
if conn_config.get("filter_dbs"):
sql = post_db.filter_dbs_sql_clause(sql,
conn_config["filter_dbs"])
LOGGER.info("Running DB discovery: %s with itersize %s", sql,
cur.itersize)
cur.execute(sql)
found_dbs = (row[0] for row in cur.fetchall())
filter_dbs = filter(
lambda dbname: attempt_connection_to_db(conn_config, dbname),
found_dbs)
for db_row in filter_dbs:
dbname = db_row
LOGGER.info("Discovering db %s", dbname)
conn_config["dbname"] = dbname
with post_db.open_connection(conn_config) as conn:
db_streams = discover_db(conn)
all_streams = all_streams + db_streams
if len(all_streams) == 0:
raise RuntimeError(
"0 tables were discovered across the entire cluster")
dump_catalog(all_streams)
return all_streams
def open_connection(conn_config, logical_replication=False):
cfg = {
"host": conn_config["host"],
"dbname": conn_config["dbname"],
"user": conn_config["user"],
"password": conn_config["password"],
"port": conn_config["port"],
"connect_timeout": 30,
}
if conn_config.get("sslmode"):
cfg["sslmode"] = conn_config["sslmode"]
if logical_replication:
cfg["connection_factory"] = psycopg2.extras.LogicalReplicationConnection
conn = psycopg2.connect(**cfg)
LOGGER.info(
"Connected with sslmode = %s",
conn.get_dsn_parameters().get("sslmode", "unknown"),
)
return conn
def sync_traditional_stream(conn_config, stream, state, sync_method, end_lsn):
LOGGER.info("Beginning sync of stream(%s) with sync method(%s)",
stream["tap_stream_id"], sync_method)
md_map = metadata.to_map(stream["metadata"])
conn_config["dbname"] = md_map.get(()).get("database-name")
desired_columns = [
c for c in stream["schema"]["properties"].keys()
if sync_common.should_sync_column(md_map, c)
]
desired_columns.sort()
if len(desired_columns) == 0:
LOGGER.warning(
"There are no columns selected for stream %s, skipping it",
stream["tap_stream_id"])
return state
register_type_adapters(conn_config)
if sync_method == "full":
state = singer.set_currently_syncing(state, stream["tap_stream_id"])
state = do_sync_full_table(conn_config, stream, state, desired_columns,
md_map)
elif sync_method == "incremental":
state = singer.set_currently_syncing(state, stream["tap_stream_id"])
state = do_sync_incremental(conn_config, stream, state,
desired_columns, md_map)
elif sync_method == "logical_initial":
state = singer.set_currently_syncing(state, stream["tap_stream_id"])
LOGGER.info("Performing initial full table sync")
state = singer.write_bookmark(state, stream["tap_stream_id"], "lsn",
end_lsn)
sync_common.send_schema_message(stream, [])
state = full_table.sync_table(conn_config, stream, state,
desired_columns, md_map)
state = singer.write_bookmark(state, stream["tap_stream_id"], "xmin",
None)
elif sync_method == "logical_initial_interrupted":
state = singer.set_currently_syncing(state, stream["tap_stream_id"])
LOGGER.info(
"Initial stage of full table sync was interrupted. resuming...")
sync_common.send_schema_message(stream, [])
state = full_table.sync_table(conn_config, stream, state,
desired_columns, md_map)
else:
raise Exception("unknown sync method {} for stream {}".format(
sync_method, stream["tap_stream_id"]))
state = singer.set_currently_syncing(state, None)
singer.write_message(singer.StateMessage(value=copy.deepcopy(state)))
return state
def sync_tables(conn_info, logical_streams, state, end_lsn):
start_lsn = min(
[get_bookmark(state, s["tap_stream_id"], "lsn") for s in logical_streams]
)
time_extracted = utils.now()
slot = locate_replication_slot(conn_info)
last_lsn_processed = None
poll_total_seconds = (
conn_info["logical_poll_total_seconds"] or 60 * 30
) # we are willing to poll for a total of 30 minutes without finding a record
keep_alive_time = 10.0
begin_ts = datetime.datetime.now()
for s in logical_streams:
sync_common.send_schema_message(s, ["lsn"])
with post_db.open_connection(conn_info, True) as conn:
with conn.cursor() as cur:
LOGGER.info(
"Starting Logical Replication for %s(%s): %s -> %s. poll_total_seconds: %s",
list(map(lambda s: s["tap_stream_id"], logical_streams)),
slot,
start_lsn,
end_lsn,
poll_total_seconds,
)
try:
cur.start_replication(slot_name=slot, decode=True, start_lsn=start_lsn)
except psycopg2.ProgrammingError:
raise Exception(
"unable to start replication with logical replication slot {}".format(
slot
)
)
rows_saved = 0
while True:
poll_duration = (datetime.datetime.now() - begin_ts).total_seconds()
if poll_duration > poll_total_seconds:
LOGGER.info(
"breaking after %s seconds of polling with no data",
poll_duration,
)
break
msg = cur.read_message()
if msg:
begin_ts = datetime.datetime.now()
if msg.data_start > end_lsn:
LOGGER.info("gone past end_lsn %s for run. breaking", end_lsn)
break
state = consume_message(
logical_streams, state, msg, time_extracted, conn_info, end_lsn
)
# msg has been consumed. it has been processed
last_lsn_processed = msg.data_start
rows_saved = rows_saved + 1
if rows_saved % conn_info["emit_state_every_n_rows"] == 0:
singer.write_message(
singer.StateMessage(value=copy.deepcopy(state))
)
else:
now = datetime.datetime.now()
timeout = keep_alive_time - (now - cur.io_timestamp).total_seconds()
try:
sel = select([cur], [], [], max(0, timeout))
if not any(sel):
LOGGER.info(
(
"no data for {} seconds. sending feedback to server with NO "
"flush_lsn. just a keep-alive"
).format(timeout)
)
cur.send_feedback()
except InterruptedError:
pass # recalculate timeout and continue
if last_lsn_processed:
for s in logical_streams:
LOGGER.info(
"updating bookmark for stream %s to last_lsn_processed %s",
s["tap_stream_id"],
last_lsn_processed,
)
state = singer.write_bookmark(
state, s["tap_stream_id"], "lsn", last_lsn_processed
)
singer.write_message(singer.StateMessage(value=copy.deepcopy(state)))
return state
def sync_table(conn_info, stream, state, desired_columns, md_map):
time_extracted = utils.now()
stream_version = singer.get_bookmark(state, stream["tap_stream_id"], "version")
if stream_version is None:
stream_version = int(time.time() * 1000)
state = singer.write_bookmark(state, stream["tap_stream_id"], "version", stream_version)
singer.write_message(singer.StateMessage(value=copy.deepcopy(state)))
schema_name = md_map.get(()).get("schema-name")
escaped_columns = map(post_db.prepare_columns_sql, desired_columns)
activate_version_message = singer.ActivateVersionMessage(
stream=post_db.calculate_destination_stream_name(stream, md_map), version=stream_version
)
singer.write_message(activate_version_message)
replication_key = md_map.get((), {}).get("replication-key")
replication_key_value = singer.get_bookmark(
state, stream["tap_stream_id"], "replication_key_value"
)
replication_key_sql_datatype = md_map.get(("properties", replication_key)).get("sql-datatype")
hstore_available = post_db.hstore_available(conn_info)
with metrics.record_counter(None) as counter:
with post_db.open_connection(conn_info) as conn:
# Client side character encoding defaults to client_encoding in postgresql.conf.
# The server / db can also have its own configred encoding.
with conn.cursor() as cur:
cur.execute("show server_encoding")
LOGGER.info("Current Server Encoding: %s", cur.fetchone()[0])
cur.execute("show client_encoding")
LOGGER.info("Current Client Encoding: %s", cur.fetchone()[0])
if hstore_available:
LOGGER.info("hstore is available")
psycopg2.extras.register_hstore(conn)
else:
LOGGER.info("hstore is UNavailable")
with conn.cursor(
cursor_factory=psycopg2.extras.DictCursor, name="stitch_cursor"
) as cur:
cur.itersize = post_db.cursor_iter_size
LOGGER.info("Beginning new incremental replication sync %s", stream_version)
if replication_key_value:
select_sql = """SELECT {}
FROM {}
WHERE {} > '{}'::{}
ORDER BY {} ASC""".format(
",".join(escaped_columns),
post_db.fully_qualified_table_name(schema_name, stream["table_name"]),
post_db.prepare_columns_sql(replication_key),
replication_key_value,
replication_key_sql_datatype,
post_db.prepare_columns_sql(replication_key),
)
else:
# if not replication_key_value
select_sql = """SELECT {}
FROM {}
ORDER BY {} ASC""".format(
",".join(escaped_columns),
post_db.fully_qualified_table_name(schema_name, stream["table_name"]),
post_db.prepare_columns_sql(replication_key),
)
LOGGER.info("select statement: %s with itersize %s", select_sql, cur.itersize)
cur.execute(select_sql)
LOGGER.info("Query returned - processing results")
rows_saved = 0
for rec in cur:
record_message = post_db.selected_row_to_singer_message(
stream, rec, stream_version, desired_columns, time_extracted, md_map
)
singer.write_message(record_message)
rows_saved = rows_saved + 1
# Picking a replication_key with NULL values will result in it ALWAYS being
# synced which is not great. Even worse would be allowing the NULL value to
# enter into the state.
if record_message.record[replication_key] is not None:
state = singer.write_bookmark(
state,
stream["tap_stream_id"],
"replication_key_value",
record_message.record[replication_key],
)
if rows_saved % conn_info["emit_state_every_n_rows"] == 0:
singer.write_message(singer.StateMessage(value=copy.deepcopy(state)))
counter.increment()
LOGGER.info("Incremental table tap complete")
return state
def sync_table(conn_info, stream, state, desired_columns, md_map):
time_extracted = utils.now()
# before writing the table version to state, check if we had one to begin with
first_run = singer.get_bookmark(state, stream["tap_stream_id"],
"version") is None
# pick a new table version IFF we do not have an xmin in our state
# the presence of an xmin indicates that we were interrupted last time through
if singer.get_bookmark(state, stream["tap_stream_id"], "xmin") is None:
nascent_stream_version = int(time.time() * 1000)
else:
nascent_stream_version = singer.get_bookmark(state,
stream["tap_stream_id"],
"version")
state = singer.write_bookmark(state, stream["tap_stream_id"], "version",
nascent_stream_version)
singer.write_message(singer.StateMessage(value=copy.deepcopy(state)))
schema_name = md_map.get(()).get("schema-name")
escaped_columns = map(post_db.prepare_columns_sql, desired_columns)
activate_version_message = singer.ActivateVersionMessage(
stream=post_db.calculate_destination_stream_name(stream, md_map),
version=nascent_stream_version,
)
if first_run:
singer.write_message(activate_version_message)
hstore_available = post_db.hstore_available(conn_info)
with metrics.record_counter(None) as counter:
with post_db.open_connection(conn_info) as conn:
# Client side character encoding defaults to client_encoding in postgresql.conf.
# The server / db can also have its own configred encoding.
with conn.cursor() as cur:
cur.execute("show server_encoding")
LOGGER.info("Current Server Encoding: %s", cur.fetchone()[0])
cur.execute("show client_encoding")
LOGGER.info("Current Client Encoding: %s", cur.fetchone()[0])
if hstore_available:
LOGGER.info("hstore is available")
psycopg2.extras.register_hstore(conn)
else:
LOGGER.info("hstore is UNavailable")
with conn.cursor(cursor_factory=psycopg2.extras.DictCursor,
name="stitch_cursor") as cur:
cur.itersize = post_db.cursor_iter_size
xmin = singer.get_bookmark(state, stream["tap_stream_id"],
"xmin")
if xmin:
LOGGER.info(
"Resuming Full Table replication %s from xmin %s",
nascent_stream_version,
xmin,
)
select_sql = """SELECT {}, xmin::text::bigint
FROM {} where age(xmin::xid) <= age('{}'::xid)
ORDER BY xmin::text::bigint ASC""".format(
",".join(escaped_columns),
post_db.fully_qualified_table_name(
schema_name, stream["table_name"]),
xmin,
)
else:
LOGGER.info("Beginning new Full Table replication %s",
nascent_stream_version)
select_sql = """SELECT {}, xmin::text::bigint
FROM {}
ORDER BY xmin::text::bigint ASC""".format(
",".join(escaped_columns),
post_db.fully_qualified_table_name(
schema_name, stream["table_name"]),
)
LOGGER.info("select %s with itersize %s", select_sql,
cur.itersize)
cur.execute(select_sql)
LOGGER.info("Query returned - processing results")
rows_saved = 0
for rec in cur:
xmin = rec["xmin"]
rec = rec[:-1]
record_message = post_db.selected_row_to_singer_message(
stream, rec, nascent_stream_version, desired_columns,
time_extracted, md_map)
singer.write_message(record_message)
state = singer.write_bookmark(state,
stream["tap_stream_id"],
"xmin", xmin)
rows_saved = rows_saved + 1
if rows_saved % conn_info["emit_state_every_n_rows"] == 0:
singer.write_message(
singer.StateMessage(value=copy.deepcopy(state)))
counter.increment()
LOGGER.info(
"Processing complete - saved {} rows".format(rows_saved))
# once we have completed the full table replication, discard the xmin bookmark.
# the xmin bookmark only comes into play when a full table replication is interrupted
LOGGER.info("Writing bookmark")
state = singer.write_bookmark(state, stream["tap_stream_id"], "xmin", None)
# always send the activate version whether first run or subsequent
LOGGER.info("Sending activate version message")
singer.write_message(activate_version_message)
LOGGER.info("Full table tap complete")
return state
