fix: remove outdated section about shutdown hooks with prisma #2797
Conversation
This section has not been relevant since the introduction of the library engine as the default in Prisma 3. Now, in Prisma 5, the code example does not compile anymore since the `beforeExit` event was removed from Prisma Client (except when generating the client with the binary engine type, which most users should not do unless they have good reasons). Note that even in Prisma 2 or when switching to the binary engine, using `beforeExit` would've only been necessary to be able to run database queries in lifecycle hooks, and wouldn't be necessary otherwise. The justification for using `beforeExit` that was present in this section was not fully accurate because while the bug it refers to (prisma/prisma#3773) was fixed together with the introduction of `beforeExit` hook (which I believe led to the confusion), those were not strictly related changes.
| } | ||
| ``` | ||
|
|
||
| > info **Note** The `onModuleInit` is optional — if you leave it out, Prisma will connect lazily on its first call to the database. We don't bother with `onModuleDestroy`, since Prisma has its own shutdown hooks where it will destroy the connection. For more info on `enableShutdownHooks`, please see [Issues with `enableShutdownHooks`](recipes/prisma#issues-with-enableshutdownhooks) |
There was a problem hiding this comment.
We don't bother with
onModuleDestroy, since Prisma has its own shutdown hooks where it will destroy the connection.
This was also a little inaccurate, at least since Prisma 3.
Prisma's own shutdown hooks in Prisma 2 (or in modern Prisma when using the binary engine) existed to kill the query engine process, but they didn't explicitly close the db connection. I'm not sure if the engine did that by catching the signal itself, but I can't seem to find that in the engines codebase.
In Prisma 3+, with library engine (a Node.js native addon), the only reason the internal shutdown hooks still existed was to maintain backward compatibility and keep the beforeExit event, but they haven't been doing anything beyond that.
If it's desired to close the connections gracefully rather than dropping them, it's still necessary to add an onModuleDestroy method with explicit $disconnect. I can do this in this PR if you'd prefer.
|
LGTM |
* remove Shutdown Hook section * not needed since prisma v3 (nestjs/docs.nestjs.com#2797)
PR Checklist
Please check if your PR fulfills the following requirements:
PR Type
What kind of change does this PR introduce?
What is the current behavior?
Current Prisma guide needs to be updated as custom
enableShutdownHooksmethod has not been necessary since Prisma 3, and now the example doesn't compile since Prisma 5.This leads to confusion for users: prisma/prisma#20171
Release notes: https://github.com/prisma/prisma/releases/tag/5.0.0
What is the new behavior?
The outdated section is removed.
Does this PR introduce a breaking change?
Other information
This section has not been relevant since the introduction of the library engine as the default in Prisma 3. Now, in Prisma 5, the code example does not compile anymore since the
beforeExitevent was removed from Prisma Client (except when generating the client with the binary engine type, which most users should not do unless they have good reasons).Note that even in Prisma 2 or when switching to the binary engine, using
beforeExitwould've only been necessary to be able to run database queries in lifecycle hooks, and wouldn't be necessary otherwise. The justification for usingbeforeExitthat was present in this section was not fully accurate because while the bug it refers to (prisma/prisma#3773) was fixed together with the introduction ofbeforeExithook (which I believe led to the confusion), those were not strictly related changes.