After #36425 there was a lot of confusions/problems with configuring pools - when the message was confusing, and settings need to be ajusted in several places.
See some examples in #44251, #43351, #47900, #46515.
The commit includes the following changes:
1) Introduced a unified mechanism for reading pool sizes from the configuration file(s). Previously, pool sizes were read from the Context.cpp with fallbacks to profiles, whereas main_config_reloader in Server.cpp read them directly without fallbacks.
2) Corrected the data type for background_merges_mutations_concurrency_ratio. It should be float instead of int.
3) Refactored the default values for settings. Previously, they were defined in multiple places throughout the codebase, but they are now defined in one place (or two, to be exact: Settings.h and ServerSettings.h).
4) Improved documentation, including the correct message in system.settings.
Additionally make the code more conform with #46550.
There are lots of thread pools and simple local-vs-global is not enough
already, it is good to know which one in particular uses threads.
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
CI reports [1]:
2023.03.14 00:29:07.031349 [ 166170 ] {110f8654-7d7d-4b47-b6b0-3ce83414a80f} <Error> ReadWriteBufferFromHTTP: HTTP request to `http://127.0.0.1:9018/columns_info?use_connection_pooling=1&version=1&connection_string=DSN%3D%7BClickHouse%20DSN%20%28ANSI%29%7D&schema=test_15&table=t&external_table_functions_use_nulls=1` failed at try 1/1 with bytes read: 0/unknown. Error: DB::HTTPException: Received error from remote server /columns_info?use_connection_pooling=1&version=1&connection_string=DSN%3D%7BClickHouse%20DSN%20%28ANSI%29%7D&schema=test_15&table=t&external_table_functions_use_nulls=1. HTTP status code: 500 Internal Server Error, body: Error getting columns from ODBC 'Code: 49. DB::Exception: Columns definition was not returned. (LOGICAL_ERROR) (version 23.2.4.12 (official build))'
[1]: https://s3.amazonaws.com/clickhouse-test-reports/47541/3d247b8635da44bccfdeb5fcd53be7130b8d0a32/upgrade_check__msan_.html
Here the problem is that system.columns has cached value for number of
total table to iterate, and so it can skip something.
But anyway, this should be LOGICAL_ERROR, since ODBC bridge does two
queries:
- to system.tables and
- to system.columns
And if between this two queries the table will be removed, them there
will be no columns
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
We have an issue when using external dictionary. Occasionally library bridge called with extDict_libClone and fails with Unknown library method 'extDict_libClone'. And it looks like it is because of at some point `else if (method == "extDict_libNew")` was changed to if (lib_new) with no handling for extDict_libClone inside this new if else statement and reporing an error that extDict_libClone is an unknown method.
So there is a two-line fix to handle extDict_libClone properly.
Error logs that we have:
```
2022.12.16 14:17:44.285088 [ 393573 ] {} <Error> ExternalDictionaries: Could not update cache dictionary 'dict.vhash_s', next update is scheduled at 2022-12-16 14:18:00: Code: 86. DB::Exception: Received error from remote server /extdict_request?version=1&dictionary_id=be2b2cd1-ba57-4658-8d1b-35ef40ab005b&method=extDict_libClone&from_dictionary_id=c3537142-eaa9-4deb-9b65-47eb8ea1dee6. HTTP status code: 500 Internal Server Error, body: Unknown library method 'extDict_libClone'
2022.12.16 14:17:44.387049 [ 399133 ] {} <Error> ExternalDictionaries: Could not update cache dictionary 'dict.vhash_s', next update is scheduled at 2022-12-16 14:17:51: Code: 86. DB::Exception: Received error from remote server /extdict_request?version=1&dictionary_id=0df866ac-6c94-4974-a76c-3940522091b9&method=extDict_libClone&from_dictionary_id=c3537142-eaa9-4deb-9b65-47eb8ea1dee6. HTTP status code: 500 Internal Server Error, body: Unknown library method 'extDict_libClone'
2022.12.16 14:17:44.488468 [ 397769 ] {} <Error> ExternalDictionaries: Could not update cache dictionary 'dict.vhash_s', next update is scheduled at 2022-12-16 14:19:38: Code: 86. DB::Exception: Received error from remote server /extdict_request?version=1&dictionary_id=2d8af321-b669-4526-982b-42c0fabf0e8d&method=extDict_libClone&from_dictionary_id=c3537142-eaa9-4deb-9b65-47eb8ea1dee6. HTTP status code: 500 Internal Server Error, body: Unknown library method 'extDict_libClone'
2022.12.16 14:17:44.489935 [ 398226 ] {datamarts_v_dwh_node0032-241534:0x552da2_1_11} <Error> executeQuery: Code: 510. DB::Exception: Update failed for dictionary 'dict.vhash_s': Code: 510. DB::Exception: Update failed for dictionary dict.vhash_s : Code: 86. DB::Exception: Received error from remote server /extdict_request?version=1&dictionary_id=be2b2cd1-ba57-4658-8d1b-35ef40ab005b&method=extDict_libClone&from_dictionary_id=c3537142-eaa9-4deb-9b65-47eb8ea1dee6. HTTP status code: 500 Internal Server Error, body: Unknown library method 'extDict_libClone'
```
Introduce new `--connection` option, by default as a connection name
`--host` will be used.
And using --connection you also can specify --host and it will be
overwritten.
Follow-up for: #45715
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
