What is Eliya?
Eliya JDK is an OpenJDK distribution built and maintained by Asymm Systems. It is distributed under GPLv2 with the Classpath Exception — the same licence as upstream OpenJDK.
Eliya exists to do three things:
- Ship upstream OpenJDK unchanged in essence. Eliya builds from the same source tree
(
openjdk/jdk25u), publishes on the same quarterly CPU cadence, and preserves API semantics. If your application runs on upstream OpenJDK 25, it runs on Eliya. - Activate telecom-optimised runtime defaults behind a single flag.
-XX:+UseEliyaDefaultsenables a curated profile (G1GC with 50 ms pause targets, string deduplication, compressed oops, tiered compilation) tuned for request-processing workloads like telecom API gateways and BSS components. Off by default — TCK compliance preserved. - Harden security defaults, always on. Eliya modifies
java.securityin the overlay to disable SSLv3, TLS 1.0, and TLS 1.1, block weak cipher suites (RC4, DES, 3DES, MD5), and enforce 2048-bit minimum key sizes. Active on every JVM invocation — no flags required.
What Eliya is not
Eliya is not a fork of OpenJDK in the sense of diverging from upstream. It is a branded build with a minimal, merge-safe source patch (the UseEliyaDefaults flag) and configuration overlays. Every quarterly upstream CPU flows into Eliya within two weeks.
Eliya is not a proprietary JVM. HotSpot is the underlying VM; no custom JIT, custom GC, or ahead-of-time compiler is layered on top. If you need those, see Azul Platform Prime or BellSoft Liberica NIK.
Eliya is not required for Dial. Dial targets JDK 25+ from any vendor — Corretto, Temurin, Zulu, Oracle, Liberica, or Eliya. Eliya is the recommended runtime because of the telecom optimisations, but never mandatory.
Relationship to upstream OpenJDK
| Layer | Source |
|---|---|
| Java APIs, compiler, standard library | Upstream openjdk/jdk25u — unchanged |
| HotSpot VM | Upstream — unchanged except the UseEliyaDefaults flag definition |
| GC defaults | Upstream defaults unless -XX:+UseEliyaDefaults is set |
java.security |
Eliya overlay — hardened |
asymm CLI (bin/asymm) |
Eliya overlay — diagnostic helper |
Overlay config (conf/eliya/) |
Eliya overlay — inspectable references |
Who Eliya is for
Eliya is built with telecom workloads in mind — BSS/OSS components, TMF Open-API gateways, request-heavy services where tail latency matters more than peak throughput. It is a reasonable default for any Linux server Java workload. It is not positioned for desktop or Windows deployments.
Eliya
Dial