storage: Fix TiFlash system tables cannot query in Keyspace Mode

[Lloyd-Pottiger]

What problem does this PR solve?

Issue Number: ref #9032

Problem Summary:

A.

❯ ~/Work/tiflash-cse/cmake-build-Debug/dbms/src/Server/tiflash client --port=9100 --host=127.0.0.1
ClickHouse client version 1.1.54381.
Connecting to 127.0.0.1:9100.
Connected to TiFlash server version 1.1.54381.

TiFlash :) show tables;

SHOW TABLES

Received exception from server (version 1.1.54381):
Code: 49. DB::Exception: Received from 127.0.0.1:9100. DB::Exception: pingcap::Exception code=UnknownError msg=unknown error : abort: "Error(InvalidKeyMode { cmd: get, storage_api_version: V2, key: \"6D536368656D6156FF65FF7273696F6E4BFF6579FF0000000000FF000000F700000000FF0000007300000000FB\" })".

0 rows in set. Elapsed: 0.641 sec.

B:

mysql> select * from information_schema.tiflash_tables;
ERROR 1105 (HY000): rpc error: code = Internal desc = pingcap::Exception code=UnknownError msg=unknown error : abort: "Error(InvalidKeyMode { cmd: get, storage_api_version: V2, key: \"6D536368656D6156FF65FF7273696F6E4BFF6579FF0000000000FF000000F700000000FF0000007300000000FB\" })"

This is because we always try to sync the schema version when querying from CLI client. Under keyspace mode, a KeyspaceID is required for it to work.

What is changed and how it works?

TiFlash's system tables don't need to sync schemas before querying. It does not belong to any keyspace as well. So we just skip sync schemas for these tables.

After this PR:

TiFlash :) show databases;

SHOW DATABASES

┌─name──────┐
│ ks_1_db_1 │
│ ks_1_db_2 │
│ system    │
└───────────┘

3 rows in set. Elapsed: 0.001 sec.

TiFlash :) select * from dt_segments;

SELECT *
FROM dt_segments

┌─database──┬─table─────┬─tidb_database─┬─tidb_table──┬─table_id─┬─is_tombstone─┬─segment_id─┬─range──────────────────────────────────────┬─epoch─┬──rows─┬──────size─┬─delta_rate─┬─delta_memtable_rows─┬─delta_memtable_size─┬─delta_memtable_column_files─┬─delta_memtable_delete_ranges─┬─delta_persisted_page_id─┬─delta_persisted_rows─┬─delta_persisted_size─┬─delta_persisted_column_files─┬─delta_persisted_delete_ranges─┬─delta_cache_size─┬─delta_index_size─┬─stable_page_id─┬─stable_rows─┬─stable_size─┬─stable_dmfiles─┬─stable_dmfiles_id_0─┬─stable_dmfiles_rows─┬─stable_dmfiles_size─┬─stable_dmfiles_size_on_disk─┬─stable_dmfiles_packs─┐
│ ks_1_db_2 │ ks_1_t_96 │ ks_1_test     │ ks_1_sample │       96 │            0 │          1 │ [-9223372036854775808,9223372036854775807) │     5 │ 60000 │ 189900000 │          0 │                   0 │                   0 │                           0 │                            0 │                      42 │                    0 │                    0 │                            0 │                             0 │                0 │             2032 │             43 │       60000 │   189900000 │              1 │                 105 │               60000 │           189900000 │                    53891161 │                    8 │
└───────────┴───────────┴───────────────┴─────────────┴──────────┴──────────────┴────────────┴────────────────────────────────────────────┴───────┴───────┴───────────┴────────────┴─────────────────────┴─────────────────────┴─────────────────────────────┴──────────────────────────────┴─────────────────────────┴──────────────────────┴──────────────────────┴──────────────────────────────┴───────────────────────────────┴──────────────────┴──────────────────┴────────────────┴─────────────┴─────────────┴────────────────┴─────────────────────┴─────────────────────┴─────────────────────┴─────────────────────────────┴──────────────────────┘

1 rows in set. Elapsed: 0.003 sec.

mysql> select * from information_schema.tiflash_tables;
+-----------+-----------+---------------+-------------+----------+--------------+---------------+------------+------------+---------------------+-----------------+---------------------+-------------------+------------------+------------------+-------------------------+------------------+------------------+------------------+-------------+------------------+------------------+----------------+----------------+-------------------------+--------------+-------------------+-------------------+---------------------------+-----------------+-----------------+---------------------------+-------------------------+-------------------------+------------------------+------------------------+----------------------------+--------------------------+-------------------------+-------------------------+------------------------------+-----------------------------------------+------------------------------------------+-------------------------------------------+-----------------------------+----------------------------------------+-----------------------------------------+------------------------------------------+----------------------------+---------------------------------------+----------------------------------------+-----------------------------------------+-------------------------+------------------+
| DATABASE  | TABLE     | TIDB_DATABASE | TIDB_TABLE  | TABLE_ID | IS_TOMBSTONE | SEGMENT_COUNT | TOTAL_ROWS | TOTAL_SIZE | TOTAL_DELETE_RANGES | DELTA_RATE_ROWS | DELTA_RATE_SEGMENTS | DELTA_PLACED_RATE | DELTA_CACHE_SIZE | DELTA_CACHE_RATE | DELTA_CACHE_WASTED_RATE | DELTA_INDEX_SIZE | AVG_SEGMENT_ROWS | AVG_SEGMENT_SIZE | DELTA_COUNT | TOTAL_DELTA_ROWS | TOTAL_DELTA_SIZE | AVG_DELTA_ROWS | AVG_DELTA_SIZE | AVG_DELTA_DELETE_RANGES | STABLE_COUNT | TOTAL_STABLE_ROWS | TOTAL_STABLE_SIZE | TOTAL_STABLE_SIZE_ON_DISK | AVG_STABLE_ROWS | AVG_STABLE_SIZE | TOTAL_PACK_COUNT_IN_DELTA | MAX_PACK_COUNT_IN_DELTA | AVG_PACK_COUNT_IN_DELTA | AVG_PACK_ROWS_IN_DELTA | AVG_PACK_SIZE_IN_DELTA | TOTAL_PACK_COUNT_IN_STABLE | AVG_PACK_COUNT_IN_STABLE | AVG_PACK_ROWS_IN_STABLE | AVG_PACK_SIZE_IN_STABLE | STORAGE_STABLE_NUM_SNAPSHOTS | STORAGE_STABLE_OLDEST_SNAPSHOT_LIFETIME | STORAGE_STABLE_OLDEST_SNAPSHOT_THREAD_ID | STORAGE_STABLE_OLDEST_SNAPSHOT_TRACING_ID | STORAGE_DELTA_NUM_SNAPSHOTS | STORAGE_DELTA_OLDEST_SNAPSHOT_LIFETIME | STORAGE_DELTA_OLDEST_SNAPSHOT_THREAD_ID | STORAGE_DELTA_OLDEST_SNAPSHOT_TRACING_ID | STORAGE_META_NUM_SNAPSHOTS | STORAGE_META_OLDEST_SNAPSHOT_LIFETIME | STORAGE_META_OLDEST_SNAPSHOT_THREAD_ID | STORAGE_META_OLDEST_SNAPSHOT_TRACING_ID | BACKGROUND_TASKS_LENGTH | TIFLASH_INSTANCE |
+-----------+-----------+---------------+-------------+----------+--------------+---------------+------------+------------+---------------------+-----------------+---------------------+-------------------+------------------+------------------+-------------------------+------------------+------------------+------------------+-------------+------------------+------------------+----------------+----------------+-------------------------+--------------+-------------------+-------------------+---------------------------+-----------------+-----------------+---------------------------+-------------------------+-------------------------+------------------------+------------------------+----------------------------+--------------------------+-------------------------+-------------------------+------------------------------+-----------------------------------------+------------------------------------------+-------------------------------------------+-----------------------------+----------------------------------------+-----------------------------------------+------------------------------------------+----------------------------+---------------------------------------+----------------------------------------+-----------------------------------------+-------------------------+------------------+
| ks_1_db_2 | ks_1_t_96 | ks_1_test     | ks_1_sample |       96 |            0 |             1 |      60000 |  189900000 |                   0 |               0 |                   0 |              NULL |                0 |             NULL |                    NULL |                0 |            60000 |        189900000 |           0 |                0 |                0 |           NULL |           NULL |                    NULL |            1 |             60000 |         189900000 |                  53891161 |           60000 |       189900000 |                         0 |                       0 |                    NULL |                   NULL |                   NULL |                          8 |                        8 |                    7500 |                23737500 |                            0 |                                       0 |                                        0 |                                           |                           0 |                                      0 |                                       0 |                                          |                          0 |                                     0 |                                      0 |                                         |                       0 | 127.0.0.1:3930   |
+-----------+-----------+---------------+-------------+----------+--------------+---------------+------------+------------+---------------------+-----------------+---------------------+-------------------+------------------+------------------+-------------------------+------------------+------------------+------------------+-------------+------------------+------------------+----------------+----------------+-------------------------+--------------+-------------------+-------------------+---------------------------+-----------------+-----------------+---------------------------+-------------------------+-------------------------+------------------------+------------------------+----------------------------+--------------------------+-------------------------+-------------------------+------------------------------+-----------------------------------------+------------------------------------------+-------------------------------------------+-----------------------------+----------------------------------------+-----------------------------------------+------------------------------------------+----------------------------+---------------------------------------+----------------------------------------+-----------------------------------------+-------------------------+------------------+
1 row in set (0.00 sec)

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

None

[JaySon-Huang]

Why querying information_schema.tiflash_tables in v7.5.x/v8.1.x are not affected?

[Lloyd-Pottiger]

Why querying information_schema.tiflash_tables in v7.5.x/v8.1.x are not affected?

Only affects keyspace mode. In v7.5.x/v8.1.x, keyspace is always equal to NullspaceID.

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-08-27 02:27:18.821671488 +0000 UTC m=+837233.956121604: ☑️ agreed by breezewish.
• 2024-08-27 02:58:18.466310205 +0000 UTC m=+839093.600760346: ☑️ agreed by JaySon-Huang.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: breezewish, JaySon-Huang, JinheLin

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[ti-chi-bot]

@Lloyd-Pottiger: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

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[Lloyd-Pottiger]

/retest