limit sql length to avoid breaking the json

[kima92]

Issue

We've identified a bug within Laravel Pulse where if the slow query detector captures an excessively large SQL statement, it leads to a disruption in the JSON schema stored in the database. This disruption makes it impossible to read the affected data, impacting the tool's ability to provide accurate insights into application performance.

Root Cause

The root cause of this issue lies in the default length of the database column designated for storing SQL statements. When a captured SQL statement exceeds this default length (65535), the resulting JSON encoding process creates a payload that violates the column's size constraints, leading to corruption of the JSON schema and subsequent data retrieval problems.

Proposed Solution

To address this issue, I propose implementing a check to truncate SQL statements to a maximum character length before encoding them into JSON. This approach ensures that the payload size remains within the database field size constraints, thus preserving the integrity of the JSON schema.

Changes Made

Start using Str::limit($sql, 65000) to make sure we are not getting too close to the limit.

Impact

This fix ensures that Laravel Pulse can handle large SQL statements without compromising the JSON schema's integrity in the database, thereby maintaining the tool's efficacy in providing performance insights.

[taylorotwell]

Drafting pending review from @jessarcher or @timacdonald

[timacdonald]

@kima92, it sounds like you have the old migration where the key was a TEXT column. We have migrated it to a MEDIUMTEXT, which should mean you can store ~16,777,215 characters, instead of the ~65,535 characters you are hitting up against.

I would recommend updating your schema to match the latest migrations.

That being said, I do feel it would be a nice additional to allow the maximum query length to be controlled. In most cases I would think that there isn't much value in having Pulse retrieve potentially megabytes worth of SQL string.

I would prefer this be a configurable option rather than a hardcoded length.

[kima92]

Thank you @timacdonald, I've updated the schema and it works great now.
Also added config with env to the code