*: move config file option query-log-max-len to sysvar

[espresso98]

What problem does this PR solve?

Issue Number: ref #33769

Problem Summary:

The option query-log-max-len has historically been a config option and tidb-query-log-max-len has existed as a session variable. Based on requirements from cloud & PM it should instead be a GLOBAL sysvar.

What is changed and how it works?

This PR converts the option query-log-max-len to a global (cluster-wide) sysvar tidb-query-log-max-len, and removes the config option and the session sysvar.

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

Please refer to Release Notes Language Style Guide to write a quality release note.

The TiDB configuration file option `query-log-max-len` has been replaced by the global system variable `tidb-query-log-max-len`.  This change makes it easier to modify this setting on a cluster wide basis.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• dveeden
• morgo

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[sre-bot]

Code Coverage Details: https://codecov.io/github/pingcap/tidb/commit/9c92c0ae1e293cb192675927d868f0cec500f28f

[espresso98]

Please review @morgo

[morgo]

LGTM, but please resolve conflicts :-)

[dveeden]

sql> SET GLOBAL tidb_query_log_max_len=5;
Query OK, 0 rows affected (0.0047 sec)

sql> select sleep(id) from t1;
+-----------+
| sleep(id) |
+-----------+
|         0 |
+-----------+
1 row in set (5.0028 sec)

# Time: 2022-05-03T08:27:00.93426371+02:00
# Txn_start_ts: 432946339101278208
# User@Host: root[root] @ ::1 [::1]
# Conn_ID: 403
# Query_time: 5.002372906
# Parse_time: 0.000205323
# Compile_time: 0.000498304
# Rewrite_time: 0.000165694
# Optimize_time: 0.000127934
# Wait_TS: 0.000028787
# Cop_time: 0.000409313 Request_count: 1
# DB: test
# Is_internal: false
# Digest: 850922af8bcba539198bb9559d6e317af6768dbd53539fee0225f44600f68688
# Stats: t1:pseudo
# Num_cop_tasks: 1
# Cop_proc_avg: 0 Cop_proc_addr: store1
# Cop_wait_avg: 0 Cop_wait_addr: store1
# Mem_max: 539
# Prepared: false
# Plan_from_cache: false
# Plan_from_binding: false
# Has_more_results: false
# KV_total: 0
# PD_total: 0.000004407
# Backoff_total: 0
# Write_sql_response_total: 0.00000353
# Result_rows: 1
# Succ: true
# IsExplicitTxn: false
# Plan: tidb_decode_plan('hAPwkDAJM18zCTAJMQlzbGVlcChjYXN0KHRlc3QudDEuaWQsIGRvdWJsZSBCSU5BUlkpKS0+Q29sdW1uIzIJMQl0aW1lOjVzLCBsb29wczoyLCBDb25jdXJyZW5jeTpPRkYJMzgwIEJ5dGVzCU4vQQoxCTMxXzUJMAkxCWRhdGE6VGFibGVGdWxsU2Nhbl80CTEJdGkBUhgxOC4xwrVzHVhwY29wX3Rhc2s6IHtudW06IDEsIG1heDogMjc5LjkFK0Rwcm9jX2tleXM6IDAsIHJwY18RKQEMBaoUIDE5OC40BS54Y29wcl9jYWNoZV9oaXRfcmF0aW86IDAuMDB9CTE1OR20JDIJNDNfNAkxXzABnwGxiDp0MSwga2VlcCBvcmRlcjpmYWxzZSwgc3RhdHM6cHNldWRvASsIaWt2CbMAewV9EDE1My42BXwAbCUtKDB9CU4vQQlOL0EK')
# Plan_digest: e81eea3563158d75f62a9ce11cffdbdb995e1c92323448dbebc16f8f154e2c46
"selec"(len:24);

[morgo]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 0e6491a

[hawkingrei]

/run-mysql-test

[sre-bot]

TiDB MergeCI notify

🔴 Bad News! New failing [1] after this pr merged.
These new failed integration tests seem to be caused by the current PR, please try to fix these new failed integration tests, thanks!

CI Name	Result	Duration	Compare with Parent commit
idc-jenkins-ci-tidb/integration-common-test	🟥 failed 1, success 10, total 11	10 min	New failing
idc-jenkins-ci/integration-cdc-test	🟢 all 34 tests passed	25 min	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-2	🟢 all 28 tests passed	6 min 43 sec	Existing passed
idc-jenkins-ci-tidb/common-test	🟢 all 12 tests passed	6 min 36 sec	Existing passed
idc-jenkins-ci-tidb/integration-ddl-test	🟢 all 6 tests passed	6 min 30 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-1	🟢 all 26 tests passed	6 min 17 sec	Existing passed
idc-jenkins-ci-tidb/tics-test	🟢 all 1 tests passed	6 min 10 sec	Existing passed
idc-jenkins-ci-tidb/integration-compatibility-test	🟢 all 1 tests passed	5 min 16 sec	Existing passed
idc-jenkins-ci-tidb/mybatis-test	🟢 all 1 tests passed	4 min 10 sec	Existing passed
idc-jenkins-ci-tidb/plugin-test	🟢 build success, plugin test success	4min	Existing passed