Performance issue calculating sha256 for generic packs

[ChipWolf]

Describe the problem

We've spotted a few servers taking several minutes to start, seemingly hanging on [init] Checking Forge version information.

After enabling debug to take a closer look, it seems the startup is hanging on this command for a significant amount of time sha256sum -c /data/.generic_pack.sum --status

Removing the sum file appears to allow the startup to proceed much faster.

Container definition

No response

Container logs

No response

[itzg]

Ah yes, I could see that being a problem. I need to revisit that section and see if the checksum process is overkill there.

[itzg]

The latest image now uses sha1 instead of sha256 which should make it faster, but not dramatically faster.

Let me know if you're interested in a variable to indicate skipping of generic pack update checks in general.

[itzg]

...I can also tag the image if that helps for your verification.

[ChipWolf]

...I can also tag the image if that helps for your verification.

Assuming it'll be on java8-openj9?

[itzg]

Yes. I now have it build all of the variants (except the old java8 one) with each push to master.

[ChipWolf]

Seems to be relatively faster @itzg

2022-02-02T21:01:49Z [init] Checking Forge version information.
2022-02-02T21:03:08Z [init] Disabling whitelist functionality

It could do with some additional logging to see what's actually happening without enabling debug there whenever you have a sec, please. I don't recall it taking very long in the past, even a 1-minute check is surprising, for us a flag to disable the check would be handy as the bootstrapping of a generic pack is quicker than this check.

[itzg]

I have now added options to skip/force, along with more logs : #1333