Files
cartodb-postgresql/scripts-available/CDB_FederatedServerDiagnostics.sql
2019-11-12 12:42:28 +01:00

222 lines
6.8 KiB
PL/PgSQL

--------------------------------------------------------------------------------
-- Private functions
--------------------------------------------------------------------------------
--
-- Import a foreign table if it does not exist
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Import_If_Not_Exists(server_internal name, remote_schema name, remote_table name)
RETURNS void
AS $$
DECLARE
local_schema name := @extschema@.__CDB_FS_Create_Schema(server_internal, remote_schema);
BEGIN
IF NOT EXISTS (
SELECT * FROM pg_class
WHERE relnamespace = (SELECT oid FROM pg_namespace WHERE nspname = local_schema)
AND relname = remote_table
) THEN
EXECUTE format('IMPORT FOREIGN SCHEMA %I LIMIT TO (%I) FROM SERVER %I INTO %I',
remote_schema, remote_table, server_internal, local_schema);
END IF;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- Get the version of a remote PG server
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Foreign_Server_Version_PG(server_internal name)
RETURNS text
AS $$
DECLARE
remote_schema name := 'pg_catalog';
remote_table name := 'pg_settings';
local_schema name := @extschema@.__CDB_FS_Create_Schema(server_internal, remote_schema);
remote_server_version text;
BEGIN
PERFORM @extschema@.__CDB_FS_Import_If_Not_Exists(server_internal, remote_schema, remote_table);
BEGIN
EXECUTE format('
SELECT setting FROM %I.%I WHERE name = ''server_version'';
', local_schema, remote_table) INTO remote_server_version;
EXCEPTION WHEN OTHERS THEN
RAISE EXCEPTION 'Not enough permissions to access the server "%"',
@extschema@.__CDB_FS_Extract_Server_Name(server_internal);
END;
RETURN remote_server_version;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- Get the PostGIS extension version of a remote PG server
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Foreign_PostGIS_Version_PG(server_internal name)
RETURNS text
AS $$
DECLARE
remote_schema name := 'pg_catalog';
remote_table name := 'pg_extension';
local_schema name := @extschema@.__CDB_FS_Create_Schema(server_internal, remote_schema);
remote_postgis_version text;
BEGIN
PERFORM @extschema@.__CDB_FS_Import_If_Not_Exists(server_internal, remote_schema, remote_table);
BEGIN
EXECUTE format('
SELECT extversion FROM %I.%I WHERE extname = ''postgis'';
', local_schema, remote_table) INTO remote_postgis_version;
EXCEPTION WHEN OTHERS THEN
RAISE EXCEPTION 'Not enough permissions to access the server "%"',
@extschema@.__CDB_FS_Extract_Server_Name(server_internal);
END;
RETURN remote_postgis_version;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- Get the foreign server options of a remote PG server
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Foreign_Server_Options_PG(server_internal name)
RETURNS jsonb
AS $$
-- See https://www.postgresql.org/docs/current/catalog-pg-foreign-server.html
-- See https://www.postgresql.org/docs/current/functions-info.html
SELECT jsonb_object_agg(opt.option_name, opt.option_value) FROM (
SELECT (pg_options_to_table(srvoptions)).*
FROM pg_foreign_server
WHERE srvname = server_internal
) AS opt;
$$
LANGUAGE SQL VOLATILE PARALLEL UNSAFE;
--
-- Get a foreign PG server hostname from the catalog
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Foreign_Server_Host_PG(server_internal name)
RETURNS text
AS $$
BEGIN
-- TODO: implement
RETURN 'localhost';
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- Get a foreign PG server port from the catalog
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Foreign_Server_Port_PG(server_internal name)
RETURNS integer
AS $$
BEGIN
-- TODO: implement
RETURN 5432;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- Get one measure of network latency in ms to a remote TCP server
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_TCP_Network_Latency(
host text,
port integer DEFAULT 5432,
timeout_seconds float DEFAULT 5.0
)
RETURNS float
AS $$
import socket
from timeit import default_timer as timer
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(timeout_seconds)
t_start = timer()
try:
s.connect((host, int(port)))
t_stop = timer()
s.shutdown(socket.SHUT_RD)
except (socket.timeout, OSError, socket.error):
return None
return (t_stop - t_start) * 1000.0
$$
LANGUAGE plpythonu VOLATILE PARALLEL UNSAFE;
--
-- Get the network latency to a remote PG server
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Foreign_Server_Latency_PG(server_internal name)
RETURNS float
AS $$
DECLARE
remote_server_host text := @extschema@.__CDB_FS_Foreign_Server_Host_PG(server_internal);
remote_server_port integer := @extschema@.__CDB_FS_Foreign_Server_Port_PG(server_internal);
latency float;
BEGIN
latency := @extschema@.__CDB_FS_TCP_Network_Latency(host => remote_server_host, port => remote_server_port);
RETURN latency;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- Collect and return diagnostics info from a remote PG into a jsonb
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_Server_Diagnostics_PG(server_internal name)
RETURNS jsonb
AS $$
DECLARE
remote_server_version text := @extschema@.__CDB_FS_Foreign_Server_Version_PG(server_internal);
remote_postgis_version text := @extschema@.__CDB_FS_Foreign_PostGIS_Version_PG(server_internal);
remote_server_options jsonb := @extschema@.__CDB_FS_Foreign_Server_Options_PG(server_internal);
remote_server_latency float := @extschema@.__CDB_FS_Foreign_Server_Latency_PG(server_internal);
BEGIN
RETURN jsonb_build_object(
'server_version', remote_server_version,
'postgis_version', remote_postgis_version,
'server_options', remote_server_options,
'server_latency', remote_server_latency
);
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--------------------------------------------------------------------------------
-- Public functions
--------------------------------------------------------------------------------
--
-- Collect and return diagnostics info from a remote PG into a jsonb
--
CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_Diagnostics(server TEXT)
RETURNS jsonb
AS $$
DECLARE
server_internal name := @extschema@.__CDB_FS_Generate_Server_Name(input_name => server, check_existence => true);
server_type name := @extschema@.__CDB_FS_server_type(server_internal);
BEGIN
CASE server_type
WHEN 'postgres_fdw' THEN
RETURN @extschema@.__CDB_FS_Server_Diagnostics_PG(server_internal);
ELSE
RAISE EXCEPTION 'Not implemented server type % for remote server %', server_type, server;
END CASE;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;