Upgrade to 3.0.0 Fails with Max Key Length Error

[timothystewart6]

How Shlink is set-up

• Shlink Version: 2.10.3 -> 3.0.0
• PHP Version: version that ships with 2.10.3 container
• How do you serve Shlink: Self-hosted Docker image
• Database engine used: MySQL

Summary

Upgrade fails with

db:migrate
An exception occurred while executing a query: SQLSTATE[42000]: Syntax error access violation: 1071 Specified key was too long; max key length is too long; max key length is 767 bytes

Current behavior

Crashloop

Expected behavior

Upgrade, no crashloop

How to reproduce

Upgraded container from 2.10.3 to 3.3.0

[acelaya]

In order to fully support emojis, Shlink 3.0.0 changes the charset for some fields from utf8 to utf8mb4, which can potentially increase the size needed to store some characters.

Probably some of those fields has or is part of some key that I missed.

I'll check which one is it.

[acelaya]

So, I have checked which of the fields getting updated to utf8mb4 have an index, and only the short_code and import_original_short_code columns in short_urls table, and the name column in tags table fulfill this condition.

The thing is that those should supposedly be pretty short, however, could it be that for you any of those has a very long value in some of the entries?

Also, could you try passing the env var SHELL_VERBOSITY=3 to the docker image? It should print more stuff when the error occurs.

[timothystewart6]

Hi and thank you! I check and my longest short code is 20 characters. I can set shell verbosity the next time I attempt the upgrade however need to accommodate for it being down.

[acelaya]

Something I forgot to ask. What MySQL version are you using?

[timothystewart6]

Sorry, something I should have included. 5.6

[acelaya]

That might be related. I have read that in versions older than 5.7, the fields which are part of the keys should have a maximum length of 191, otherwise it can throw this error even if there are no value longer than that.

Some of the fields I mentioned have a length of 255, so that might be the problem.

I'll try to reproduce this with MySQL 5.6 and let you know.

[acelaya]

Confirmed. This happens only with MySQL 5.6

@timothystewart6 I would suggest updating to MySQL 5.7, as 5.6 is no longer actively supported.

[timothystewart6]

Thank you and sorry. Will migrate soon. I used this version because another old app requires it, missed that Postgres was supported in the docs or I would have just used that. Sorry to waste your time. Thanks for a great product!

[acelaya]

No worries! I'm just glad to know what's the root cause.

[timothystewart6]

Just reporting back. I ended up moving to Postgres (thanks to your guide on moving instances) and everything is working after the upgrade. I did lost my stats because of an error with max size during the transfer but getting on Postgres was more important than a legacy version of mysql. Thanks again!