Frequently Asked Questions

When multiple Node.js processes initialize the Statsig SDK simultaneously, they might all try to write to the file at the same time, which could lead to race conditions or other issues. To mitigate this, you can use a locking mechanism to ensure that only one process writes to the file at a time. This could be a file-based lock, a database lock, or another type of lock depending on your application's architecture and requirements.

Another approach could be to have a single process responsible for writing to the file. This could be a separate service or a designated process among your existing ones. This process would be the only one to initialize Statsig with the rulesUpdatedCallback, while the others would initialize it with just the bootstrapValues.Remember to handle any errors that might occur during the file writing process to ensure your application's robustness.

If you're using a distributed system, you might want to consider using something like Redis, which is designed to handle consumers across a distributed system. Statsig's Data Adapter is designed to handle this so you don't need to build this manually. You can find more information about the Data Adapter in the Data Adapter overview and the Node Redis data adapter.

However, for these types of cases, it's recommended to only have a single data adapter that is enabled for writes, so you don't run into concurrent write issues.If your company doesn't currently use Redis for anything else and you use GCP buckets for file storage, there's no need to adopt Redis. The data adapter is the latest supported way to accomplish what you're trying to do.

In terms of performance, startup time is the primary concern here. And write() performance to an extent, though if you limit that to a single instance that issues writes, they should be infrequent.

In the case of using both the front end and the back end SDKs in tandem, this is common. You can even use the server SDKs to bootstrap the client SDKs (so that there’s no asynchronous request back to statsig to get assignments). For more notes on resilience and best practices, you can refer to the Statsig reliability FAQs.