Login with mysql client lost username will be hang

[wubx]

Summary

use mysql client login databend lost username will be hang.

$mysql -h127.0.0.1 -P3307

databend-query + databend-meta

mysql> select version();
+-------------------------------------------------------------------------------------+
| version()                                                                           |
+-------------------------------------------------------------------------------------+
| DatabendQuery v-0.1.0-aaeb1dc-simd(1.60.0-nightly-2022-02-14T16:33:14.231860+00:00) |
+-------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
Read 1 rows, 1 B in 0.001 sec., 1.31 thousand rows/sec., 1.31 KB/sec.

mysql> show processlist;
+--------------------------------------+-------+-----------------+------+-------+----------+------------------+--------------+------------------------+-------------------------+-------------------------+--------------------------+
| id                                   | type  | host            | user | state | database | extra_info       | memory_usage | dal_metrics_read_bytes | dal_metrics_write_bytes | scan_progress_read_rows | scan_progress_read_bytes |
+--------------------------------------+-------+-----------------+------+-------+----------+------------------+--------------+------------------------+-------------------------+-------------------------+--------------------------+
| a8eb5161-a777-481d-be8b-c304cd464837 | MySQL | 127.0.0.1:63458 | NULL | Query | default  |                  |            0 |                      0 |                       0 |                       0 |                        0 |
| f7692569-2a3d-440a-b920-c652f6448a85 | MySQL | 127.0.0.1:62881 | NULL | Query | default  |                  |            0 |                      0 |                       0 |                       0 |                        0 |
| daa50c12-dd6b-4868-a5e2-33433f149e43 | MySQL | 127.0.0.1:62811 | NULL | Query | default  |                  |            0 |                      0 |                       0 |                       0 |                        0 |
| db02d1b6-ea7f-43ef-9569-04960f81c7eb | MySQL | 127.0.0.1:62818 | root | Query | default  | show processlist |            0 |                      0 |                       0 |                       0 |                        0 |
+--------------------------------------+-------+-----------------+------+-------+----------+------------------+--------------+------------------------+-------------------------+-------------------------+--------------------------+
4 rows in set (0.00 sec)
Read 4 rows, 732 B in 0.003 sec., 1.43 thousand rows/sec., 261.5 KB/sec.

Note: User column is: NULL

Please make errors like single databend-query.

[flaneur2020]

/assignme

[flaneur2020]

it seems the process hangs at the grpc client get_kv() method:

and the default grpc client timeout is 60 seconds

[BohuTANG]

We can track the metasrv log to see what is said.

[flaneur2020]

after setting the grpc client time out as 1 second, the do_read function also get hangs.

it seems hangs at the make_client routine on getting an instance from the pool:

[flaneur2020]

it seems get hangs in the handshake among connecting a grpc channel:

[flaneur2020]

as @zhang2014 suggested, we can not safely create tonic channel in a block_on().

this issue might relevant, let's try make the authenticate() method async.
datafuse-extras/msql-srv#21