MySQl deoesn't seem to close the connection properly

[CoenBlijker]

Dear Mr Bell,

I am running several ESP32 clients against a MariaDB server running on my Synology NAS.

The MariaDB log file is filling up with messages like:

2024-04-21` 14:32:36 170 [Warning] Aborted connection 170 to db: 'unconnected' user: 'coen' host: '192.168.178.4' (Got an error reading communication packets)

2024-04-21 14:33:18 172 [Warning] Aborted connection 172 to db: 'unconnected' user: 'coen' host: '192.168.178.181' (Got an error reading communication packets)

The code running on all these ESP32 is basically the same and comes down to:

WiFiClient` mySQLwifiClient;
MySQL_Connection conn((Client *)&mySQLwifiClient);
MySQL_Cursor cur = MySQL_Cursor(&conn);

bool connectToMySQL()
{
    if (!conn.connected())
    {
        if (!conn.connect(server_addr, 3306, mySQLuser, mySQLpassword))
        {
            logTimedConstMessage("MySQL connect failed..\n");

            return false;
        }
        logTimedConstMessage("MySQL connect succeeded..\n");
    }
    return true;
}

void execQuery(const char *query)
{
    if (!connectToMySQL())
    {
        return;
    }
    // Execute the query
    if (!cur.execute(query, false))
    {
        logTimedMessage("*** Exec query: '%s' failed..\n", query);
    }

    // Note: since there are no results, we do not need to read any data
    cur.close();
    conn.close();
}

After some 'research' on Google the only (possibly) relevant answer I could find is that the client doesn't seems to close the connection properly before exiting (does not call mysql_close()).

Looking at your code I don't see any code that implements some form of formal disconnect from the DB. The conn.close() call just closes the connection.

Am I missing something? Or does MariaDB behave differently than MySQL?

Any help on this issue would be greatly appropriated!

With kind regards,

Coen