The problem is that completion request can takes too much time,
especially with S3 storage, and because of this it fails sometimes after
client writes "Bye.", like here [1]:
2023-03-07 22:20:22 send: sending "\u0004" to { exp7 }
2023-03-07 22:20:22 Bye.
2023-03-07 22:20:22 [?2004lexpect: timed out
[1]: https://s3.amazonaws.com/clickhouse-test-reports/47295/946dff2d04e7f7af8d3541ed7de11f195b521b6c/stateless_tests__release__s3_storage__[2/2].html
And from server logs:
2023.03.07 22:19:21.885151 [ 41723 ] {00cb66fe-d01f-40ca-a6ef-b7dbd9f69d9e} <Trace> ContextAccess (default): Access granted: CREATE DATABASE ON test_4xqrwzwv.*
...
2023.03.07 22:19:22.286606 [ 5806 ] {} <Debug> TCPHandler: Connected ClickHouse client version 23.3.0, revision: 54461, database: test_4xqrwzwv, user: default.
2023.03.07 22:19:22.287361 [ 5806 ] {1493527c-8b85-4080-be82-a1c78829a104} <Debug> executeQuery: (from [::1]:40978) SELECT DISTINCT arrayJoin(extractAll(name, '[\\w_]{2,}')) AS res FROM (SELECT * FROM viewIfPermitted(SELECT name FROM system.functions ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT name FROM system.table_engines ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT name FROM system.formats ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT name FROM system.table_functions ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT name FROM system.data_type_families ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT name FROM system.merge_tree_settings ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT name FROM system.settings ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT cluster FROM system.clusters ELSE null('cluster String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT macro FROM system.macros ELSE null('macro String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT policy_name FROM system.storage_policies ELSE null('policy_name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT concat(func.name, comb.name) AS x FROM system.functions AS func CROSS JOIN system.aggregate_function_combinators AS comb WHERE is_aggregate ELSE null('x String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT name FROM system.databases LIMIT 10000 ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT DISTINCT name FROM system.tables LIMIT 10000 ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT DISTINCT name FROM system.dictionaries LIMIT 10000 ELSE null('name String')) UNION ALL SELECT * FROM viewIfPermitted(SELECT DISTINCT name FROM system.columns LIMIT 10000 ELSE null('name String'))) WHERE notEmpty(res) (stage: Complete)
...
2023.03.07 22:20:22.316230 [ 58563 ] {} <Trace> DynamicQueryHandler: Request URI: /?query=DROP+DATABASE+IF+EXISTS+test_4xqrwzwv&database=system&connect_timeout=539&receive_timeout=539&send_timeout=539&http_connection_timeout=539&http_receive_timeout=539&http_send_timeout=539&log_comment=01300_client_save_history_when_terminated_long.expect
...
2023.03.07 22:20:45.575830 [ 5806 ] {1493527c-8b85-4080-be82-a1c78829a104} <Warning> TCPHandler: Client has gone away.
2023.03.07 22:20:45.575843 [ 5806 ] {1493527c-8b85-4080-be82-a1c78829a104} <Debug> TCPHandler: Processed in 83.289128886 sec.
So query for autocomplete takes 83 seconds!
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
Prevous implementation (DBMS_MIN_REVISION_WITH_INTERSERVER_SECRET)
accepts the salt from the client, which make it useless.
Reimplement the protocol to send the salt by the server and use it in
the client instead.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
