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Regular db pings to reconnect after timed out connections #41819

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Merged
juliusknorr merged 1 commit into from
Jan 12, 2024
Merged

Regular db pings to reconnect after timed out connections #41819

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27 changes: 27 additions & 0 deletions lib/private/DB/Connection.php
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,7 @@
use Doctrine\DBAL\Connections\PrimaryReadReplicaConnection;
use Doctrine\DBAL\Driver;
use Doctrine\DBAL\Exception;
use Doctrine\DBAL\Exception\ConnectionLost;
use Doctrine\DBAL\Platforms\MySQLPlatform;
use Doctrine\DBAL\Platforms\OraclePlatform;
use Doctrine\DBAL\Platforms\SqlitePlatform;
Expand Down Expand Up @@ -78,6 +79,7 @@ class Connection extends PrimaryReadReplicaConnection {

/** @var DbDataCollector|null */
protected $dbDataCollector = null;
private array $lastConnectionCheck = [];

protected ?float $transactionActiveSince = null;

Expand Down Expand Up @@ -127,10 +129,13 @@ public function __construct(
public function connect($connectionName = null) {
try {
if ($this->_conn) {
$this->reconnectIfNeeded();
/** @psalm-suppress InternalMethod */
return parent::connect();
}

$this->lastConnectionCheck[$this->getConnectionName()] = time();
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@artonge artonge Feb 18, 2025

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$this->getConnectionName() will return replica when the $this->_conn is null.
So, on initialization, we will always save:

$this->lastConnectionCheck =  [
  'replica' => time(),
],


// Only trigger the event logger for the initial connect call
$eventLogger = \OC::$server->get(IEventLogger::class);
$eventLogger->start('connect:db', 'db connection opened');
Expand Down Expand Up @@ -679,4 +684,26 @@ public function rollBack() {
}
return $result;
}

private function reconnectIfNeeded(): void {
if (
!isset($this->lastConnectionCheck[$this->getConnectionName()]) ||
$this->lastConnectionCheck[$this->getConnectionName()] + 30 >= time() ||
$this->isTransactionActive()
Comment on lines +690 to +692
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@artonge artonge Feb 18, 2025

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Regarding this condition: !isset($this->lastConnectionCheck[$this->getConnectionName()])

This means that if we never saved the last connection check for a connection, we are skipping the reconnect logic?

Practically, this seems like for single DB server setups, we are always skipping the reconnect logic, as $this->getConnectionName() returns replica before initialization, and primarry afterward.

) {
return;
}

try {
$this->_conn->query($this->getDriver()->getDatabasePlatform()->getDummySelectSQL());
$this->lastConnectionCheck[$this->getConnectionName()] = time();
} catch (ConnectionLost|\Exception $e) {
$this->logger->warning('Exception during connectivity check, closing and reconnecting', ['exception' => $e]);
$this->close();
}
}

private function getConnectionName(): string {
return $this->isConnectedToPrimary() ? 'primary' : 'replica';
}
}