Como resolver erros de timeout com as funções de tabela `remote` e `remoteSecure`

Saiba como corrigir erros de timeout ao usar as funções de tabela remote ou remoteSecure no ClickHouse, ajustando as configurações de timeout da conexão.

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Código: 279. DB::NetException: Todas as tentativas de conexão falharam.

Problema A função de tabela remote() ou remoteSecure() permite acessar uma tabela remota em outro nó do ClickHouse.

Ao usar essas funções em um nó localizado a mais de 100 ms (em termos de latência) do nó remoto, é comum ocorrer um erro de timeout.

Por exemplo:

4776d4bd8190 :) SELECT * FROM remoteSecure('HOSTNAME.us-east-2.aws.clickhouse.cloud', DATABASE, TABLE, 'USER', 'USER_PASSWORD')

SELECT *
FROM remoteSecure('HOSTNAME.us-east-2.aws.clickhouse.cloud', DATABASE, TABLE, 'USER', 'USER_PASSWORD')

Query id: 2bd6ddd0-66d9-4d19-830f-87e3cec3724b

0 rows in set. Elapsed: 1.213 sec.

Received exception from server (version 22.6.9):
Code: 519. DB::Exception: Received from localhost:9000. DB::NetException. DB::NetException: All attempts to get table structure failed. Log:

Code: 279. DB::NetException: All connection tries failed. Log:

Code: 209. DB::NetException: Timeout: connect timed out: 18.218.245.169:9440 (hc7d963h1t.us-east-2.aws.clickhouse.cloud:9440, connection timeout 100 ms). (SOCKET_TIMEOUT) (version 22.6.9.11 (official build))
Code: 209. DB::NetException: Timeout: connect timed out: 18.218.245.169:9440 (hc7d963h1t.us-east-2.aws.clickhouse.cloud:9440, connection timeout 100 ms). (SOCKET_TIMEOUT) (version 22.6.9.11 (official build))
Code: 209. DB::NetException: Timeout: connect timed out: 18.218.245.169:9440 (hc7d963h1t.us-east-2.aws.clickhouse.cloud:9440, connection timeout 100 ms). (SOCKET_TIMEOUT) (version 22.6.9.11 (official build))

. (ALL_CONNECTION_TRIES_FAILED) (version 22.6.9.11 (official build))

. (NO_REMOTE_SHARD_AVAILABLE)

Solução alternativa Para aumentar o timeout da conexão, defina connect_timeout_with_failover_secure_ms para um valor mais alto (por exemplo, 1 segundo) em vez do valor padrão de 100 ms.

4776d4bd8190 :) SELECT * FROM remoteSecure('HOSTNAME.us-east-2.aws.clickhouse.cloud:9440', DATABASE, TABLE, 'USER', 'USER_PASSWORD') SETTINGS connect_timeout_with_failover_secure_ms = 1000

SELECT *
FROM remoteSecure('HOSTNAME.us-east-2.aws.clickhouse.cloud:9440', DATABASE, TABLE, 'USER', 'USER_PASSWORD')
SETTINGS connect_timeout_with_failover_secure_ms = 1000

Query id: 8e2f4d41-307b-4e61-abb8-809190023247

┌─x─┐
│ 1 │
└───┘

1 row in set. Elapsed: 2.403 sec.