Compatibility breaks in Embulk v0.9

(Copied from an old post in the embulk-announce mailing list.)


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We’ll be releasing Embulk v0.9 in a couple of months, which expects some compatibility breaks from the v0.8 series. Some existing plugins may not work in v0.9. Let me summarize the expected breaks here, and ask a favor of you to give your feedbacks for us on the expected compatibility breaks.

tl;dr for Users

The biggest change is that Embulk v0.9 would expect Java 8. Embulk core would be tested only in Java 8 (and possibly Java 9 in addition sooner or later… hopefully). Plugins compiled with Java 8 features are welcome then!

Next, we stop providing embulk.gem from v0.9. If you are using embulk.gem and/or require 'embulk' from Ruby, please see and comment in: https://github.com/embulk/embulk/issues/628 and/or https://github.com/embulk/embulk/issues/766

Then, please try Embulk v0.8.36 soon with the plugins and the usages which you actually operate. You’d see some warning messages like below on your console (stderr) if your usage expects compatibility breaks.

===== Example warning message =====
[WARN] Plugin uses deprecated constructor of
[WARN] Report plugins in your config at:
===== Example warning message =====

If you see such warning messages, please report in the GitHub Issues URL in your case. We’d provide how to workaround, notify the developer of the plugin, or reconsider the breakage then.

for Plugin Developers

v0.9 would introduce 6 types of plugin SPI incompatibilities as of now. They are related with JRuby which we’re removing from Embulk’s deeply-tightened dependencies in v0.9. Some of them are related with Timestamps which have been unnecessarily depending on JRuby.

1) Some constructors of TimestampParser and TimestampFormatter


It could be the most impactful on plugins. TimestampParser and TimestampFormatter have been constructed with JRuby instances, but the constructors will be removed in v0.9. The GitHub Issue above describes how to workaround this incompatibility.

2) AbstractDynamicColumnSetter#setRubyObject


We expect no plugins are calling this method directly. Ruby’s PageBuilder had been calling it inside Embulk core, but the part is now replaced to pure-Ruby implementation. Please ping us if your plugin is calling the method directly.

3) RubyValueApi


We expect no plugins are using this class directly. It had been a static utility class to convert internal MessagePack values and JRuby values inside Embulk core, but the part is now replaced to pure-Ruby implementation. Please ping us if your plugin is using this class directly.

4) Timestamp#getRubyTime or Timestamp.fromRubyTime


We expect no plugins are using these methods directly. The methods had been used to convert Embulk Timestamps and JRuby’s time objects inside Embulk core, but the part is now replaced to pure-Ruby implementation. Please ping us if your plugin is calling the methods directly.

5) Some constructors of PagePrinter


We expect no plugins are using PagePrinter. The class had been used from embedded StdoutOutputPlugin. StdoutOutputPlugin now calls PagePrinter’s new constructor.

6) TimestampFormat: newFormatter and newParser


We expect no plugins are using these methods to create TimestampFormatter and/or TimestampParser. They have been @Deprecated for a long time since v0.6.14.