Truncate Doctrine\DBAL\Exception\DriverException message if too long

[shtrom]

Hi have an issue---triggered by ownCloud and an erroneous vCard with a duplicated PHOTO field---where a database insertion request into MySQL via the Doctrine DBAL fails.

Essentially, the blob inserted is too big for MySQL, and it issues a Syntax error or access violation: 1118 The size of BLOB/TEXT data inserted in one transaction is greater than 10% of redo log size.” which gets transformed into a Doctrine\DBAL\Exception\DriverException.

The message for the exception is An exception occurred while executing [QUERY] with params [PARAMS]. This is where the issue with Doctrine is: the blob is about 9MiB at this stage, and it is dumped verbatim as part of the PARAMS bit in the error message. This makes the Exception a bit hard to understand, as it is not concise enough, and this makes log files grow at a very very high rate.

A solution to this problem would be to either

• truncate or ellipsise PARAMS longer than a given threshold in the error message, e.g., BEGIN:VCARD\r ... END:VCARD\r(line ending might or might not be a good idea to rely on)
• not reproduce blobs, and replace them altogether with something like BLOB of 9MiB, or
• a combination of both: BEGIN:VCARD\r [about 9MiB of blob] END:VCARD\r.

Note that my example is with ownCloud and vCards, but the problem is more generic, with any blob too big for comfortable display.

[kimhemsoe]

Sounds to me that it is the exception handler which prints out the exception. Any reason why this could not be fixed in the presentation of the exception?

[shtrom]

This could work. However the DBALException (well, driverExceptionDuringQuery) has a better view into which $param is the longest, and can cut the cruft more accurately, without touching the others.

In my example above, there is still valuable information at the end of the exception (in the output of ->getMessage()), which would otherwise be removed at the logging site by, e.g., an mb_strimwidth, as I've used in my test above.

[shtrom]

Yup, the fix in the commit above fixes the issue nicely, while retaining useful information. It truncates the long blob properly, but retains useful things such as the stacktrace after that.

[Ocramius]

Looking at #2524, I think this is up to the exception handler printing the error. It is indeed a lot of data, but imagine having an incorrect character at position 2500 (invalid encoding), and then going mad :-P

[shtrom]

It is indeed a lot of data, but imagine having an incorrect character at position 2500 (invalid encoding)

Right, I didn't consider this.

That said, if the exception handler truncates the whole message, you will lose the information too, but also the rest of the error message, with a potentially much more helpful “invalid encoding”. If we just truncate the parameter here, the exception handler will still be able to get and display the error message from the database.

Perhaps there can be a middle ground, where we give a formatted message, but add the full parameters to the Exception as additional properties, or the other way round?

[shtrom]

If we just truncate the parameter here, the exception handler will still be able to get and display the error message from the database.

What I mean is something like in this pseudo example.

Truncate in the exception handler:

An exception occurred while executing [QUERY] with params [PARAM1, PARAM2, PARA...

Truncate the parameter in in the exception formatter:

An exception occurred while executing [QUERY] with params [PARAM1, PARAM2, PARA..., PARAM4]: Syntax error or access violation: 1118 The size of BLOB/TEXT data inserted in one transaction is greater than 10% of redo log size.

I think truncating late leads to a much less useful error message.

[scaytrase]

Is it possible just to make the original message (or the whole driver exception) from dbal driver exception https://github.com/doctrine/dbal/blob/master/lib/Doctrine/DBAL/Exception/DriverException.php#L38 accessible via doctrine exception interface?

In out case we handle some exception conversions by ourselves so it would be handy just to have a string like

SQLSTATE[22003]: Numeric value out of range: 7 ERROR:  value \"9223372036854775807\" is out of range for type integer",

to view

[morozov]

This should have been fixed by #4387.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.