Artery was added in Akka 2.5.0 but do note that a long time has passed since 2.5.32 which was the last 2.5 release. Bug and security fixes as well as performance improvements has only happened to the active 2.6 branch since then, and we are not actively maintaining 2.5 anymore. (Note that this will also soon change for for 2.6 after 2.6.20 except critical issues however Akka 2.7 will be a drop in replacement for 2.6).
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