Cache Variable vs Static Class Concept Question

I have been working with the fundamental assumption that if a large data set needed to be stored for use by other services during the same request, i.e. a Job or single HTTP request, these two questions help me determine whether to use a static property inside a dedicated class, or a Cache::get() scenario.

If data is required by multiple users simultaneously, then it should be in a Cache variable.
If data is only required by the single process/request running at the time then a dedicated class with a static property set early in that process is a better way to go.

Does this summarize the extent of the things that make this decision for us?

Or is there a better way to determine when to use classes vs cached variable values?

My particular use case that helped me form these 2 rules mentally is a pretty standard ETL (a term I recently learned!!)

I fetch large amounts of external API data json objects from multiple external sources and then transform and load that data to my own mysql database. The frontside application only ever queries my loaded data tables. Sometimes the fetched API single data json gets transformed and loaded into a handful of smaller segmented tables, and during this JOB that could feasibly be running once per minute during the NFL season, or once per day in the off-season would need the original raw data stored into either Cache or a static class property.

I found the the static class property to be way faster for my use case, and was curious if I have now formed this assumption about the "best way to approach this concept" a little naively or if this is a fundamentally sound way to approach things.

I guess I am asking "are the two rules above okay to apply universally across all my future projects?" In y'all's opinion?

LaryAI

1 year ago

Level 58

Your understanding and approach to using static properties versus caching are generally sound, but let's refine the decision-making process a bit more.

When to Use Static Properties

Single Request/Process Scope: If the data is only needed within the scope of a single request or process, using a static property is appropriate. This is because static properties are stored in memory and are accessible throughout the lifecycle of the request, making them fast and efficient for temporary data storage.
Performance: Static properties are faster than cache because they don't involve I/O operations. If performance is critical and the data doesn't need to persist beyond the request, static properties are a good choice.
Data Volatility: If the data changes frequently and doesn't need to be shared across requests, static properties are suitable.

When to Use Cache

Multiple Requests/Users: If the data needs to be shared across multiple requests or users, caching is the way to go. Cache systems like Redis or Memcached are designed to store data that needs to be accessed by different parts of an application or by different users.
Persistence: If the data needs to persist beyond the lifecycle of a single request, caching is necessary. This is especially true for data that is expensive to compute or fetch.
Data Consistency: If the data needs to be consistent across requests, caching can help maintain a single source of truth.

Considerations for ETL Processes

In your ETL scenario, where you fetch, transform, and load data frequently:

Static Properties: Use them for temporary storage of data that is only needed during the transformation process of a single job. This is efficient and reduces overhead.
Cache: Use it if you need to store intermediate results that might be reused by other jobs or if the transformation process is distributed across multiple workers that need access to the same data.

Conclusion

Your rules are a good starting point, but always consider the specific requirements of your application, such as data persistence, access patterns, and performance needs. It's also important to monitor and profile your application to ensure that your chosen approach meets your performance and scalability requirements.

Here's a simple example of using a static property in a class:

class DataProcessor {
    private static $data;

    public static function setData($data) {
        self::$data = $data;
    }

    public static function getData() {
        return self::$data;
    }
}

// Usage
DataProcessor::setData($largeDataSet);
$processedData = DataProcessor::getData();

And an example of using cache:

use Illuminate\Support\Facades\Cache;

// Store data in cache
Cache::put('largeDataSet', $largeDataSet, now()->addMinutes(10));

// Retrieve data from cache
$cachedData = Cache::get('largeDataSet');

Ultimately, the choice between static properties and caching should be guided by the specific needs of your application and the characteristics of the data you're working with.